Device and method for determining liquid contact and liquid volume in a liquid dispenser based on sound

Abstract

Devices and methods are provided for determining contact between a liquid dispenser and a liquid based on sound and / or for determining the volume of liquid within a liquid dispenser. According to one embodiment, a liquid dispenser includes a sound generator and an acoustic sensor, wherein at least one of the sound generator or acoustic sensor is disposed within a dispense chamber portion. According to one embodiment, the liquid dispenser includes the sound generator and the acoustic sensor, and further includes one or more side conduits, wherein at least one of the sound generator or acoustic sensor is disposed within a respective cavity of the one or more side conduits, wherein the cavity and connector of each of the one or more side conduits are free of resonance within a frequency range of sound sensed by the acoustic sensor.

Description

[Technical Field]

[0001] Related Articles This application claims the benefit of prior U.S. Application No. 62 / 869,725, filed July 2, 2019, the entire contents of which are incorporated herein by reference.

[0002] The present invention is directed to devices and methods for detecting liquid contact and liquid volume in a liquid dispenser based on sound. [Background technology]

[0003] A liquid dispenser can be used to transport a specific amount of liquid from a reservoir that stores the liquid to a target location. The use of a liquid dispenser can be automated using a liquid dispenser and an automated liquid dispenser system that can move the liquid dispenser's piston. For example, the automated dispenser system can control the liquid dispenser to draw a specific amount of liquid from a liquid reservoir and dispense the specific amount of liquid to a target location with little or no human intervention. To draw liquid, the automated dispenser system can lower the liquid dispenser until the dispensing tip of the liquid dispenser sufficiently contacts the liquid, and then draw liquid into the liquid dispenser until a specific volume is reached. To accurately draw a specific volume of liquid, the automated dispenser system must be able to lower the liquid dispenser sufficiently until the dispensing tip of the liquid dispenser contacts the liquid. Furthermore, automated pipette systems must ensure that the dispensing tip of a liquid dispenser does not descend too far into the liquid, as this can cause the liquid to adhere to the outer wall of the dispensing tip, which can then cause errors in the amount of liquid delivered by the dispensing tip. Accordingly, various approaches have been developed to accurately detect the gas-liquid boundary by determining whether contact has occurred between the dispensing tip of a pipette and the liquid. Summary of the Invention

[0004] One aspect of the embodiments herein relates to a liquid dispenser. The liquid dispenser includes a dispenser body having a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber via the second opening and configured to guide a piston in a linear motion within the piston chamber to draw liquid into the liquid dispenser and dispense liquid out of the liquid dispenser. The liquid dispenser further includes a sound generator configured to generate sound to induce acoustic resonance within the dispense chamber. The liquid dispenser further includes an acoustic sensor configured to sense sound within the dispense chamber, with at least one of the sound generator or the acoustic sensor disposed within the dispense chamber portion. The liquid dispenser may further include control circuitry for determining whether contact between the dispensing tip and the liquid has occurred based on the sensed sound.

[0005] One aspect of the embodiments herein relates to a liquid dispenser. The liquid dispenser includes a dispenser body having a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, one or more side conduits, each having a respective cavity and a respective connector channel connecting the respective cavity to the dispense chamber, and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber through the second opening and configured to direct a piston in a linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser. The liquid dispenser further includes a sound generator configured to generate sound to induce acoustic resonance within the dispense chamber. The liquid dispenser may further include an acoustic sensor configured to sense sound within the dispensing chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within a cavity of each of the one or more side conduits, and the cavity and connector of each of the one or more side conduits is free of resonance within a frequency range of the sound sensed by the acoustic sensor. The liquid dispenser may further include control circuitry configured to determine whether contact between the dispensing tip and the liquid has occurred based on the sensed sound.

[0006] One aspect of the embodiments herein relates to a liquid dispenser. The liquid dispenser includes a dispenser body including a dispense chamber portion having a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, and a piston chamber portion having a piston chamber therein, the piston chamber connected to the dispense chamber through the second opening and configured to guide a piston in a linear motion within the piston chamber to draw liquid into the liquid dispenser and dispense liquid out of the liquid dispenser; and an acoustic filter disposed between the dispense chamber and the piston chamber, the acoustic filter configured to acoustically isolate the dispense chamber from the piston chamber. The liquid dispenser further includes a sound generator configured to generate sound in the dispense chamber. The liquid dispenser further includes an acoustic sensor configured to sense an acoustic signal resulting from the generated sound. The liquid dispenser may further include a control circuit configured to determine at least one of whether contact between the dispensing tip and the liquid has occurred based on the sensed sound, or the volume of liquid in the dispensing tip based on the sensed sound.

[0007] One aspect of embodiments herein relates to a method for detecting contact between a liquid and a liquid dispenser. The method includes obtaining, via an acoustic sensor, a plurality of voltage values ​​associated with sound sensed by the acoustic sensor within a time window. The method further includes squaring each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window. The method further includes calculating an average value of the plurality of squared voltage values ​​for the time window. The method further includes determining whether contact between a dispenser tip of the liquid dispenser and the liquid occurred during the time window based on the average value of the plurality of squared voltage values. [Brief explanation of the drawings]

[0008] The foregoing and other features, objects, and advantages of the present invention will become apparent from the following description of embodiments thereof, as illustrated in the accompanying drawings, which are incorporated in and form a part of this specification and further serve to explain the principles of the invention and to enable those skilled in the art to make and use the invention. The drawings are not to scale. [Figure 1A] FIG. 1 shows a block diagram of a liquid dispenser system for transporting and dispensing liquids configured to detect tip-liquid contact. [Figure 1B] FIG. 1 shows a block diagram of a controller for a liquid dispenser system. [Figure 2A-2B] 2A and 2B are exemplary diagrams showing a liquid dispenser system configured to detect tip-liquid contact and a cross-sectional view of a portion of the liquid dispenser shown in FIG. 2A. [Figures 2C-2D] 2C is another exemplary diagram showing a liquid dispenser system 298 configured to detect tip-liquid contact. FIG. 2D is an exemplary diagram showing a cross-sectional view of a portion of the liquid dispenser shown in FIG. 2C. [Figure 3] FIG. 1 is an exemplary diagram showing a cross-sectional view of an example liquid dispenser. [Figure 4] Calculation of acoustic resonance frequencies based on the geometry of the side conduit including the connecting channel and cavity is shown. [Figure 5A] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser with a short side conduit structured to avoid acoustic resonance within a frequency range for sound sensing, according to an embodiment of the present disclosure. [Figure 5AA] 5B is an exemplary diagram showing the calculation of the acoustic resonance frequency based on the geometry of the side conduit including the connecting channel and cavity for the embodiment shown in FIG. 5A. FIG. [Figure 5B] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser with a single, short side conduit structured to avoid acoustic resonance within the frequency range for sound sensing, according to an embodiment of the present disclosure. [Figure 5C]FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser with a single, short side conduit structured to avoid acoustic resonance within the frequency range for sound sensing, according to an embodiment of the present disclosure. [Figure 6] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser for avoiding acoustic resonance within a frequency range for sensing sound, according to an embodiment herein. [Figure 7] 10 illustrates a calculation of the resonant frequency of sound in a connecting channel between a cavity and a dispensing chamber when the width of the cavity and the width of the connecting channel are substantially the same, according to an embodiment herein. [Figures 8A-8C] 10A-10C show experimental results based on a liquid dispenser when the width of the cavity and the width of the connecting channel are substantially the same, according to an embodiment herein. [Figure 9A] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser for avoiding acoustic resonance within a frequency range for sensing sound, according to an embodiment herein. [Figure 9AA] FIG. 9B is an exemplary diagram showing a calculation of the acoustic resonance frequency in the connecting channel between the cavity and the dispensing chamber for the embodiment shown in FIG. 9A. [Figure 10A] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser for avoiding acoustic resonance within a frequency range for sensing sound, according to an embodiment herein. [Figure 10AA] FIG. 10B is an exemplary diagram showing a calculation of the acoustic resonance frequency in the connecting channel between the cavity and the dispensing chamber for the embodiment shown in FIG. 10A. [Figure 11A] FIG. 10 is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser with a short side conduit structured to avoid acoustic resonance within a frequency range for sound sensing, according to an embodiment of the present disclosure. [Figure 11AA] FIG. 11B is an exemplary diagram showing a calculation of the acoustic resonance frequency in the connecting channel between the cavity and the dispensing chamber for the embodiment shown in FIG. 11A. [Figure 12]1 is an exemplary diagram illustrating a liquid dispenser system including a cross-sectional view of a liquid dispenser according to an embodiment herein. [Figure 13] FIG. 10 is an exemplary diagram illustrating an exemplary acoustic filter implemented in a liquid dispenser, according to an embodiment of the present disclosure. [Figure 14A] 10A-10C are exemplary diagrams showing plots illustrating the frequency spectrum of an acoustic signal at various piston positions within the piston chamber and different liquid levels within the dispenser tip, according to one embodiment without an acoustic filter. [Figure 14B] FIG. 10 is an exemplary diagram showing a plot illustrating the frequency spectrum of an acoustic signal at various piston positions within the piston chamber and different liquid levels within the dispenser tip, according to one embodiment with an acoustic filter. [Figure 15A] 1 is an exemplary diagram showing acoustic spectra at different acoustic filter thicknesses when the acoustic filter is made of polyethylene (PE). FIG. [Figure 15B] 1 is an exemplary diagram showing acoustic spectra at different thicknesses of an acoustic filter when the acoustic filter is made of polyurethane (PU). FIG. [Figure 16A] FIG. 10 is an exemplary diagram showing that different liquid levels in a dispensing tip correspond to different frequencies when the acoustic filter is 5 mm thick. [Figure 16B] FIG. 10 is an exemplary diagram showing that different liquid levels in a dispensing tip correspond to different frequencies when the acoustic filter is 10 mm thick. [Figure 17] 1 is an exemplary diagram illustrating a liquid dispenser system including a cross-sectional view of a liquid dispenser with an acoustic filter according to an embodiment herein. [Figure 18] FIG. 10 is an exemplary diagram illustrating false positive errors due to white noise when using sound amplitude to detect tip-liquid contact. [Figure 19] FIG. 10 is an exemplary diagram illustrating false positive errors due to single tone noise when using sound amplitude to detect tip-liquid contact. [Figure 20] 1 shows an exemplary diagram illustrating false positive errors due to airflow noise. [Figure 21] 1 shows a flow diagram of an exemplary method for detecting contact between a dispenser and a liquid. [Figure 22] FIG. 10 is an exemplary diagram showing experimentally acquired acoustic spectra for multiple tip conditions. [Figure 23] 1 shows a flow diagram of a method for chip presence detection consistent with embodiments herein. [Figure 24] FIG. 10 is an exemplary diagram showing experimentally obtained acoustic spectra for multiple dispensing tip types. [Figures 25A-25E] FIG. 10 is an exemplary diagram showing experimentally obtained acoustic spectra for multiple dispensing tip types. [Figures 26A-26E] FIG. 10 is an exemplary diagram showing experimentally acquired acoustic spectra at multiple temperatures for a single dispensing tip. [Figures 27A-27E] FIG. 10 is an exemplary diagram showing experimentally acquired acoustic spectra at multiple temperatures for a single dispensing tip. [Figures 28A-28D] FIG. 10 is an exemplary diagram showing experimentally acquired acoustic spectra at multiple temperatures and multiple volume levels for a single dispensing tip. [Figure 29] FIG. 10 is an exemplary diagram showing experimentally obtained acoustic spectra for multiple dispensing tip types. [Figure 30] 1 shows a flow diagram of a method for chip identification consistent with embodiments herein. [Figure 31] FIG. 10 is an exemplary block diagram showing a block diagram for processing the voltage output from the acoustic sensor. [Figure 32] FIG. 10 is an exemplary diagram illustrating the elimination of false positive errors when tip-liquid contact is detected based on a value associated with the average power or intensity of sound. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following detailed description is merely exemplary in nature and is not intended to limit the invention, its application, and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description.

[0010]

[0003] Embodiments described herein relate to devices and methods for detecting liquid contact by a liquid dispenser, such as a pipette. Other embodiments described herein relate to devices and methods for determining the volume of liquid in a liquid dispenser. To provide for effective drawing of liquid into the liquid dispenser, automated liquid dispenser systems can be configured to detect when contact between a dispensing tip and a liquid (e.g., tip-liquid contact) occurs. One approach can detect when a tip of the liquid dispenser contacts a liquid by detecting a change in a characteristic of sound sensed by an acoustic sensor. In particular, the liquid dispenser can include a dispensing chamber connected to the dispensing tip, which can provide a particular sound characteristic. When the dispensing tip contacts a liquid, the characteristic of sound within the dispensing chamber can change due to at least the liquid blocking the dispensing tip. Thus, a sound generator and an acoustic sensor can be implemented with the liquid dispenser such that the sound generator can generate a sound that travels within the dispensing chamber of the liquid dispenser, and the acoustic sensor can sense an acoustic signal resulting from the sound generated within the dispensing chamber of the liquid dispenser. The automated liquid dispenser system can determine that the tip of the liquid dispenser has contacted a liquid when the automated liquid dispenser system detects a significant change in the acoustic signal sensed by the acoustic sensor. Additionally, embodiments described herein improve the accuracy of tip-liquid contact detection and minimize errors based on the structure of the automated liquid dispenser system and / or the method of detection based on the sensed acoustic signal.

[0011] The acoustic sensor and sound generator may be implemented within the structure of the liquid dispenser. For example, an acoustic sensor that senses an acoustic signal within the liquid dispenser and a sound generator that provides sound to the interior of the liquid dispenser may be disposed within respective protruding side structures connected to the dispense chamber of the liquid dispenser. Such protruding structures may be referred to as side conduits and may extend outward from the dispense chamber to provide sufficient space to accommodate the acoustic sensor and sound generator, respectively. The embodiments described herein prevent the side conduits from extending to form structures that may introduce undesirable acoustic resonances that cause errors in the detection of tip-liquid contact. For example, if an acoustic resonance formed by the side conduit falls near an acoustic resonance associated with the detection of tip-liquid contact, the threshold for determining tip-liquid contact may become sensitive to dimensional changes in the side conduit. In one example, the dimensional change may include a change in the cavity volume within the side conduit due to a change in the position of the sensor and / or generator within the side conduit. Furthermore, the embodiments described herein similarly prevent interference with the implementation of liquid volume sensing. For example, resonances formed by side conduits can introduce significant distortion into the sound spectrum that would otherwise be sensed by the acoustic sensor, making it difficult to establish a clear relationship between peak frequency and desired liquid volume. Accordingly, the invention described herein provides improvements to the structure housing the acoustic sensor and sound generator to reduce or avoid these undesirable acoustic resonances.

[0012] One aspect of the embodiments herein relates to improving the accuracy of tip-liquid contact detection through structural improvements including a sound generator and an acoustic sensor. In one embodiment, the dispense chamber of a liquid dispenser can be configured so that the sound generator and acoustic sensor can be disposed within the dispense chamber instead of using a side conduit. In this embodiment, there is no side conduit protruding from and connected to the dispense chamber, thereby reducing or avoiding undesirable acoustic resonance caused by a protruding side conduit. According to another embodiment, side conduits protruding from the dispense chamber of a liquid dispenser can be used to house the sound generator and acoustic sensor, and the structure of the side conduit can be configured to avoid undesirable acoustic resonance. In particular, the length of each side conduit can be limited to a specific length compared to the opening and interior space of the side conduit to maintain the resonant frequency caused by the side conduit within a specific range.

[0013] In some embodiments, the liquid dispenser may also have a piston chamber connected to the dispense chamber of the liquid dispenser. The piston chamber can receive and guide the movement of the piston, so that liquid can be drawn in or dispensed by pressure induced by the piston movement. Piston movement can cause additional noise that can be detected by an acoustic sensor. Other changes in acoustic characteristics caused by piston movement can introduce errors into the acoustic signal detected by the acoustic sensor. Therefore, the present disclosure provides approaches for reducing or eliminating the adverse effects of piston movement, as described in more detail below.

[0014] One aspect of the embodiments herein relates to improving the accuracy of tip-liquid contact detection and / or substantially improving the accuracy of sensing liquid within the tip (liquid volume sensing) by implementing an acoustic filter disposed between the dispense chamber and piston chamber of a liquid dispenser. More specifically, the acoustic filter can be selected and positioned such that it can acoustically isolate the dispense chamber from the piston chamber. In this way, the effect of piston movement within the piston chamber on the acoustic signal sensed by the acoustic sensor can be reduced or eliminated.

[0015] Furthermore, several approaches can be developed to detect tip-liquid contact using the acoustic signal sensed by the acoustic sensor. For example, tip-liquid contact can be detected by measuring changes in amplitude / phase or acoustic impedance based on the acoustic signal sensed by the acoustic sensor. However, such approaches may have a high rate of false positive detection of tip-liquid contact as background noise increases. Because liquid dispensers may operate in a constant noisy environment, background noise is an important factor to consider when detecting tip-liquid contact. Therefore, the present disclosure provides an approach for detecting tip-liquid contact that is less affected by background noise, as described in more detail below.

[0016] One aspect of the embodiments herein relates to improving the accuracy of tip-liquid contact detection by using an improved approach for processing acoustic signals sensed by an acoustic sensor to detect tip-liquid contact. Instead of relying solely on amplitude / phase or acoustic impedance, the acoustic power or acoustic intensity of the sound sensed by the acoustic sensor may be monitored. In particular, tip-liquid contact may be detected based on detected changes in values ​​associated with acoustic power or acoustic intensity.

[0017] FIG. 1A shows a block diagram of a liquid dispenser system 100 (e.g., an automated pipetting system) for transporting and dispensing a liquid. The liquid dispenser system 100 may include a controller 110 configured to control various components of the liquid dispenser system 100, a liquid dispenser 130 for transporting the liquid, a piston driver 180 for driving a piston 170 of the liquid dispenser 130, and a liquid dispenser transport device 185 for driving the liquid dispenser 130. In one embodiment, the controller 110 may be part of the liquid dispenser 130 or may be a separate device from the liquid dispenser 130. In one embodiment, the liquid dispenser 130 may be a pipette, and the liquid dispenser system 100 may be an automated pipette system. The piston driver 180 may include one or more motors controlled by the controller 110 to drive the piston 170, and may be coupled to the piston 170. The liquid dispenser transport device 185 may include one or more motors controlled by the controller 110 to drive the liquid dispenser 130 and may be coupled to the liquid dispenser 130. The liquid dispenser 130 may include a sound generator 150 configured to generate a sound and an acoustic sensor 160 configured to sense an acoustic signal. A piston 170 of the liquid dispenser 130 may be configured to move within the liquid dispenser 130 to generate pressure within the liquid dispenser 130 to draw liquid into or dispense liquid out of the liquid dispenser 130. The liquid dispenser 130 may include a dispenser body 131 that includes the sound generator 150 and the acoustic sensor 160. The dispenser body 131 may be structured to receive and guide the movement of the piston 170.

[0018] The controller 110 may be configured to receive and process acoustic signals sensed by the acoustic sensor 160 and to detect whether contact between the liquid dispenser 130 and the liquid has occurred (e.g., via the dispensing tip), as discussed in more detail below. The controller 110 may be configured to control the sound generator 150 to generate sounds. For example, the controller 110 may set various settings for sound generation by the sound generator 150, such as the frequency of the sound, the type of sound, the duration of the sound, and the intensity / volume of the sound. The controller 110 may further be configured to control the piston driver 180 to drive the piston 170. For example, the controller 110 may control the piston driver 180 to drive the piston 170 based on whether the controller 110 determines to draw liquid into the liquid dispenser 130 or dispense liquid out of the dispenser 130. The controller 110 may further be configured to control the liquid dispenser transport device 185 to drive the liquid dispenser 130. For example, the controller 110 can control the liquid dispenser transport device 185 so that the liquid dispenser transport device 185 moves the liquid dispenser 130 to a liquid reservoir, draws liquid from the liquid reservoir, and moves the liquid dispenser 130 to a target location for dispensing the liquid.

[0019] In one embodiment, the controller 110 may be configured to communicate with the liquid dispenser 130 (e.g., the sound generator 150 and the acoustic sensor 160), the piston driver 180, and the liquid dispenser transport device 185 via wired or wireless communication. For example, the controller 110 may be configured to communicate with a serial peripheral interface (SPI), 2The controller 110 may be configured to communicate with the liquid dispenser 130, the piston drive 180, and / or the liquid dispenser transport device 185 via a C (Inter-Integrated Circuit) bus, an RS-232 interface, a Universal Serial Bus (USB) interface, an Ethernet interface, a Bluetooth interface, an IEEE 802.11 interface, or any combination thereof. In one embodiment, the controller 110 may be configured to communicate with the liquid dispenser 130, the piston drive 180, and / or the liquid dispenser transport device 185 via a local computer bus, such as a Peripheral Component Interconnect (PCI) bus. In one embodiment, the controller 110 may be separate from the liquid dispenser 130 and may communicate with the dispenser 130 via a wireless or wired connection as discussed above. In one embodiment, the controller 110 may be an integral component of the liquid dispenser 130 and may communicate with other components of the liquid dispenser 130 and / or the piston drive 180 and / or the liquid dispenser transport device 185 via the local computer bus as discussed above. In some cases, controller 110 may be a dedicated controller that controls only liquid dispenser 130. In other cases, controller 110 may be configured to control multiple liquid dispensers, including liquid dispenser 130. In one embodiment, controller 110 and liquid dispenser 130 are located in the same facility (e.g., a laboratory). In another embodiment, controller 110 may be remote from liquid dispenser 130, piston driver 180, and liquid dispenser transport device 185 and may be configured to communicate with liquid dispenser 130, piston driver 180, and liquid dispenser transport device 185 via a network connection (e.g., a local area network (LAN) connection).

[0020] 1B shows a block diagram of the controller 110 of the liquid dispenser system 100. As shown in the block diagram, the controller 110 includes a control circuit 111, a communication interface 113, and a non-transitory computer-readable medium 115 (e.g., memory or other computer-readable storage medium). In one embodiment, the control circuit 111 may include one or more processors, a programmable logic circuit (PLC) or programmable logic array (PLA), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or any other control circuit.

[0021] In one embodiment, communication interface 113 may include one or more components configured to communicate with liquid dispenser 130 (e.g., sound generator 150 and acoustic sensor 160), piston driver 180, and liquid dispenser transport device 185. For example, communication interface 113 may include communication circuitry configured to perform communications via a wired or wireless protocol. By way of example, the communication circuitry may include an SPI controller, an I 2 The communication circuitry may include a C controller, an RS-232 port controller, a USB controller, an Ethernet controller, a Bluetooth controller, a PCI bus controller, any other communication circuitry, or a combination thereof.

[0022] In one embodiment, non-transitory computer-readable medium 115 may include computer memory. Computer memory may include, for example, flash, electrically erasable programmable read-only memory (EEPROM), dynamic random access memory (DRAM), solid-state integrated memory, and / or a hard disk drive (HDD). In some cases, various methods described herein may be performed via computer-executable instructions (e.g., computer code) stored on non-transitory computer-readable medium 115. In such cases, control circuitry 111 may include one or more processors configured to execute the computer-executable instructions (e.g., the steps illustrated in FIG. 18 ).

[0023] The controller 110 may further include an analog-to-digital converter 117 that converts analog signals to digital signals. The analog-to-digital converter 117 may be an optional component. In one embodiment, the output signals from the acoustic sensors 160 are analog signals and therefore may be converted to digital signals using the analog-to-digital converter 117 so that they can be further processed by the control circuitry 111. The controller 110 may further include a digital-to-analog converter 119 that converts digital signals to analog signals. The digital-to-analog converter 119 may be an optional component. In one embodiment, the input signals to the sound generator 150 are analog signals and therefore may be derived from the digital signals generated from the control circuitry 111 using the digital-to-analog converter 119.

[0024] The controller 110 may further include a signal conditioning circuit 121. The signal conditioning circuit 121 may manipulate various analog signals so that they meet the requirements of the next stage for further processing. The signal conditioning circuit 121 may include an amplifier that receives an input signal, amplifies the input signal, and outputs the amplified input signal as an output signal. In one aspect, an amplifier may be used to amplify the input signal so that the sound output from the sound generator 150 can reach a desired volume range based on the input signal generated by the control circuit 111. In one embodiment, an analog amplifier may be used to amplify the input signal associated with the sound sensed by the acoustic sensor 160 so that the output signal from the acoustic sensor 160 can reach a desired level that matches the input range of the analog-to-digital converter 117. The signal conditioning circuit 121 may further include an active / passive filter for the signal. For example, the filter may be a low-pass filter configured to pass signals with frequencies below a cutoff frequency and discard signals with frequencies at or above the cutoff frequency. The low-pass filter may be used to output a smoother form of the input signal. Thus, a low-pass filter can be used to reduce noise. In one embodiment, the output signal from acoustic sensor 160 may be passed through a low-pass filter, for example, to perform initial smoothing of the output signal from acoustic sensor 160.

[0025] FIG. 2A is an exemplary diagram showing a liquid dispenser system 200 configured to detect tip-liquid contact. FIG. 2B is an exemplary diagram showing a cross-sectional view of a portion of a liquid dispenser 230 of liquid dispenser system 200. Liquid dispenser system 200 may be an exemplary embodiment of liquid dispenser system 100 of FIG. 1, and thus, components of liquid dispenser system 200 may correspond to components of liquid dispenser system 100. Liquid dispenser system 200 includes a liquid dispenser 230 controlled by controller 110. Liquid dispenser 230 may include a dispenser body 231 including a dispense chamber portion 240 and a piston chamber portion 275. Dispenser body 231 of liquid dispenser 230 may be contained within housing 235, which may be an optional structure.

[0026] Dispense chamber portion 240 includes dispensing chamber 241 having a first opening in first portion 243 of dispensing chamber 241 and a second opening in second portion 245 of dispensing chamber 241 connected to piston chamber 277. First portion 243 may be at a first end of dispensing chamber 241, and second portion 245 may be at a second end of dispensing chamber 241. Liquid dispenser 230 further includes piston 270, which is received and guided by piston chamber 277 within piston chamber portion 275 of dispenser body 231. First portion 243 of dispensing chamber 241 is configured to mate with a dispensing tip, such as dispensing tip 247. Dispensing tip 247 may be permanently attached to first portion 243 or may be removably attached to first portion 243. In one example, dispense tip 247 can be part of dispense chamber portion 240. The cavity of dispense tip 247, dispense chamber 241, and piston chamber 277 are connected to one another, so that piston 270 can be moved to change the pressure within dispense chamber 241 and draw liquid into dispense tip 247. Liquid dispenser system 200 includes a liquid dispenser transport device 285 configured to drive liquid dispenser 230 and a piston driver 280 configured to drive piston 270 within piston chamber 277. Dispense tip 247 can be configured to dispense volumes ranging from 5 μl to 1000 μl, although other volumes are contemplated. In an exemplary embodiment, dispense tip 247 is a 350 μl volume tip. Additionally, dispense tip 247 can include an off-the-shelf automation tip, such as a TECAN brand or RAININ brand tip, or a conductive type tip adapted to employ capacitive sensing. Additionally, dispensing tip 247 can dispense at various dispensing rates ranging from 5 μl / sec to 700 μl / sec, although other rates are contemplated. For example, in a non-limiting exemplary embodiment, dispensing tip 247 is adapted to dispense at approximately 600 μl / sec.

[0027] In one example, the liquid dispenser transport device 285 can move the liquid dispenser 230 over a liquid reservoir 295 containing the liquid 290 and lower the liquid dispenser 230 toward the liquid 290 until the dispensing tip 247 contacts the liquid 290. When the controller 110 detects that the dispensing tip 247 has contacted the liquid 290, the controller 110 can control the liquid dispenser transport device 285 to stop the movement of the liquid dispenser 230. The controller 110 can then further control the piston driver 280 to move the piston 270 upward to draw a specific amount of liquid 290 into the dispensing tip 247. After the specific amount of liquid 290 has been drawn, the controller 110 can control the piston driver 280 to stop the movement of the piston 270 and control the liquid dispenser transport device 285 to move the liquid dispenser 230 to a target position. Once the target position is reached, the controller 110 can control the piston driver 280 to move the piston 270 downward to dispense the liquid from the dispensing tip 247.

[0028] Dispenser body 231 of liquid dispenser 230 may include sound generator 250 that generates sound within dispense chamber 241 to induce acoustic resonance within dispense chamber 241. Dispenser body 231 of liquid dispenser 230 may include acoustic sensor 260 that can sense sound from dispense chamber 241. The non-limiting exemplary embodiment shown in FIG. 2A shows sound generator 250 and acoustic sensor 260 disposed opposite each other and spaced apart from each other. However, the arrangement and relative positions of sound generator 250 and acoustic sensor 260 are not limited to the example of FIG. 2A . For example, in another example, sound generator 250 and acoustic sensor 260 may not face each other and / or may be disposed adjacent to each other.

[0029] FIG. 2C is another exemplary diagram illustrating a liquid dispenser system 298 configured to detect tip-liquid contact. The liquid dispenser system 298 of FIG. 2C may be similar to the liquid dispenser system 200 of FIG. 2A, except for the location of the sound generator 250. Notably, the sound generator 250 in the liquid dispenser system 298 may be located outside the liquid dispenser 230. In one embodiment, the liquid dispenser system 298 may include an opening or gap to allow the sound generated by the sound generator 250 to travel to the acoustic sensor 260. FIG. 2D is an exemplary diagram illustrating a cross-sectional view of a portion of the liquid dispenser 230 of the liquid dispenser system 298. As discussed above, the liquid dispenser system 298 of FIG. 2C may be similar to the liquid dispenser system 200 of FIG. 2A, except for the location of the sound generator 250. Thus, FIG. 2D illustrates the same features as FIG. 2B.

[0030] FIG. 3 is an exemplary diagram showing a cross-sectional view of liquid dispenser 330. In one embodiment, liquid dispenser 330 may be an embodiment of liquid dispenser 230. In the embodiment shown in FIG. 3, liquid dispenser includes a dispenser body 331 including a dispense chamber portion 340 and a piston chamber portion 375. Dispense chamber portion 340 has a dispense chamber 341 therein. Dispense chamber 340 may have a first opening at a first portion 343 of dispense chamber 340 and a second opening at a second portion 345 of dispense chamber 340. First portion 343 of dispense chamber 340 is coupled to a dispense tip 347. Dispense chamber 341 is connected to a piston chamber 377 of piston chamber portion 375 via a second opening at second portion 345. Piston chamber 377 is configured to direct piston 370 in linear motion within piston chamber 377 to draw liquid into liquid dispenser 330 and dispense liquid out of liquid dispenser 330 (e.g., via dispensing tip 347). Liquid can be drawn into tip cavity 349 of dispensing tip 347 and dispensed out of tip cavity 349 based on movement of piston 370.

[0031] Dispenser body 331 further includes a first side conduit 355 having a first cavity 357 and a first connecting channel 359 connecting first cavity 357 to dispensing chamber 341. Sound generator 350 may be disposed within first cavity 357 and may generate sound to induce acoustic resonance within dispensing chamber 341. Dispenser body 331 further includes a second side conduit 365 having a second cavity 367 and a second connecting channel 369 connecting second cavity 367 to dispensing chamber 341. Acoustic sensor 360 may be disposed within second cavity 367 and may sense sound from dispensing chamber 341.

[0032] In the embodiment shown in FIG. 3 , first conduit 355 and second conduit 365 protrude from dispensing chamber portion 340. Furthermore, first conduit 355 and second conduit 365 are implemented with large sizes to accommodate large sound generator 350 and acoustic sensor 360, respectively. As described in more detail below, the structure of first conduit 355 and second conduit 365 can contribute to errors in detecting whether dispensing tip 347 has contacted a liquid. For example, to avoid undesirable errors, acoustic resonances induced by first conduit 355 and / or second conduit 365 should be outside the frequency range used to detect tip-liquid contact. In one example, a desired frequency range for detecting tip-liquid contact may be 200 Hz to 1 kHz, or preferably 100 Hz to 4 kHz. Therefore, acoustic resonances induced by first conduit 355 and / or second conduit 365 should be outside this described frequency range.

[0033] FIG. 4 illustrates a calculation of the resonant frequency of sound at the connecting channel of a side conduit based on the side conduit's geometry. A structure with a cavity, such as cavity 457, with a small opening, such as the opening provided by connecting channel 459, can form a Helmholtz resonator. In one embodiment, first cavity 357 and first connecting channel 359 of first side conduit 355 of FIG. 3 can have a similar structure to cavity 457 and connecting channel 459, respectively. In one embodiment, second cavity 367 and second connecting channel 369 of second side conduit 365 of FIG. 3 can have a similar structure to cavity 457 and connecting channel 459.

[0034] 4, the side conduit may have a cavity 457 with a known volume V and a connecting channel 459 with a neck length L, the connecting channel 459 having an opening area A, where c denotes the speed of sound, and the resonant frequency f may be calculated based on the following equation:

number

[0035] The Helmholtz resonator formed by cavity 457 and connecting channel 459 can function as a notch filter that can add distortion to the acoustic spectrum. In particular, the resonant frequency f introduced by the Helmholtz resonator can interfere with the frequency range of sound used to detect tip-liquid contact. In one example, the cavity width, cavity length, and neck length L can each be 15 mm, and the connecting channel width can be 4 mm. In such an example, the volume V is approximately 2649 mm. 3 and the opening area A is 12.56 mm 2where the speed of sound is 343 m / s (or 343,000 mm / s). In this example, according to the above equation, the resonant frequency f may be approximately 971 Hz. If the frequency range of the sound used to detect tip-liquid contact is 200 Hz to 1 kHz, or preferably 100 Hz to 4 kHz, then the resonant frequency of 971 Hz falls within this frequency range and may interfere with the detection of tip-liquid contact. Therefore, the structure housing the sound generator and acoustic sensor should be designed to avoid acoustic resonances that fall within the frequency range used to detect tip-liquid contact.

[0036] According to one embodiment, the side conduit can be designed so that its resonant frequency f lies outside the frequency range of sound used to detect tip-liquid contact. Therefore, the cavity and connector of the side conduit can be configured so that there is no acoustic resonance within the frequency range of sound sensed by the acoustic sensor to detect tip-liquid contact. In one embodiment, the volume V of the cavity and the opening area A and neck length L of the connector of the side conduit can be determined so that the resonant frequency f lies outside the frequency range of sound used to detect tip-liquid contact. For example, a preferred frequency range for detecting tip-liquid contact can be 100 Hz to 4 kHz. Thus, in such an example, the opening area A, volume V, and neck length L can be selected to ensure frequencies below 100 Hz or above 4 kHz. Based on the above equation, the resonant frequency can be increased beyond the frequency range used to detect tip-liquid contact by increasing the opening area A and / or decreasing the volume V and / or decreasing the neck length L. For example, selecting a smaller sound generator and acoustic sensor allows for a decrease in the volume V and / or a decrease in the neck length L. Thus, a structure with a resonant frequency f outside the frequency range of sound may reduce or eliminate errors caused by the resonant frequency f, and thus may improve the accuracy of detecting tip-liquid contact, as well as detecting the presence of a tip (e.g., detecting whether the tip has been ejected) or the type of dispensing tip.

[0037] Figure 5A is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 530 with a side conduit structured to avoid acoustic resonance within the sound frequency range sensed by an acoustic sensor of the liquid dispenser 530, according to one embodiment herein. Figure 5AA is an exemplary diagram showing a calculation of sound resonant frequencies based on the shape of the side conduit, including the connecting channel and cavity, for the embodiment shown in Figure 5A. In Figure 5A, portions represented by reference numerals 535, 540, 541, 543, 545, 547, 549, 570, 575, and 577 have similar features to portions represented by reference numerals 340, 341, 343, 345, 347, 349, 370, 375, and 377, respectively, discussed above with reference to Figure 3. Therefore, detailed discussion of reference numbers 535, 540, 541, 543, 545, 545, 549, 570, 575, and 577 will be omitted.

[0038] 5A , liquid dispenser 530 has dispenser body 531 including first side conduit 555 having first cavity 557 and first connector channel 559 connecting first cavity 557 to dispense chamber 541. Sound generator 550 may be disposed within first cavity 557 and may generate sound to induce acoustic resonance within dispense chamber 541. Dispenser body 531 includes second side conduit 565 having second cavity 567 and second connector channel 569 connecting second cavity 567 to dispense chamber 541. Acoustic sensor 560 may be disposed within second cavity 567 and may sense sound within dispense chamber 541. The arrangement of sound generator 550 and acoustic sensor 560, as well as the number of side conduits implemented, may not be limited to the example shown in FIG. 5A . For example, in another example, a sound generator and / or acoustic sensor may be disposed within a single side conduit.

[0039] In the embodiment shown in FIG. 5A, the sound generator 550 of the liquid dispenser 530 is smaller than the sound generator 350 of the liquid dispenser 330 of FIG. 3. Furthermore, with respect to the embodiment shown by FIG. 5A, the acoustic sensor 560 of the liquid dispenser 530 is smaller than the acoustic sensor 360 of the liquid dispenser 330 of FIG. 3. Therefore, compared to the liquid dispenser 330 of FIG. 3, the volume V of the cavity of each side conduit is reduced. Furthermore, compared to the liquid dispenser 330 of FIG. 3, the neck length L, which corresponds to the length of the connecting channel of each side conduit, is also reduced. The reduction in the cavity volume V and neck length L, as shown in FIG. 5A, can be achieved by implementing a smaller sound generator and a smaller acoustic sensor. In the embodiment shown in FIG. 5A, the sound generator 550 of the liquid dispenser 530 is smaller than the sound generator 350 of the liquid dispenser 330 of FIG. 3. Furthermore, in the embodiment illustrated by Figure 5A, the acoustic sensor 560 of the liquid dispenser 530 is smaller than the acoustic sensor 360 of the liquid dispenser 330 of Figure 3. By decreasing the cavity volume V and neck length L, the resonant frequency f increases to frequencies above the acoustic frequency range used to detect tip-liquid contact.

[0040] In the above example referring to Figures 3 and 4, the volume V is 2649 mm 3 The neck length L is 15 mm and the opening area A is 12.56 mm 2 and the speed of sound is 343 m / s, the resonant frequency f is about 971 Hz. In FIG. 5A, in one example, the cavity width can be reduced to 5 mm, the cavity length and neck length L can each be reduced to 4 mm, while the connector channel width can be 4 mm. In this example, the cavity volume V of each side conduit can be reduced to 78.5 mm. 3 while the opening area A of the connector channel is 12.56 m 2The resonant frequency f can be set to approximately 10.9 kHz, where the speed of sound is 343 m / s (or 343,000 mm / s). Therefore, the resonant frequency f is approximately 10.9 kHz. If the preferred frequency range for detecting tip-liquid contact is 100 Hz to 4 kHz, then a resonant frequency f of 10.9 kHz is outside the frequency range for detecting tip-liquid contact and therefore does not adversely affect tip-liquid contact detection. This example shows that decreasing the volume V and neck length L can increase the resonant frequency f to exceed or otherwise fall outside the frequency range for detecting tip-liquid contact.

[0041] FIG. 5B is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 580 with a single, short side conduit structured to avoid acoustic resonance within a frequency range for sound sensing, according to one embodiment herein. The embodiment shown in FIG. 5B can be considered a variation of the embodiment shown in FIG. 5A. In the embodiment of FIG. 5B, a single side conduit is implemented instead of having two side conduits as shown in FIG. 5A. In the embodiment shown by FIG. 5B, liquid dispenser 580 has a dispenser body 531′ including a first side conduit 555 having a first cavity 557 and a first connector channel 559 connecting first cavity 557 to dispense chamber 541. Sound generator 550 can be disposed within first cavity 557 and can generate sound to induce acoustic resonance within dispense chamber 541. Dispenser body 531′ does not have a second side conduit. Thus, acoustic sensor 560 can be disposed within second cavity 567 ′ of dispense chamber portion 540 and can sense sounds within dispense chamber 541 .

[0042] FIG. 5C is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 590 with a single, short side conduit structured to avoid acoustic resonance within a frequency range for sound sensing, according to an embodiment herein. The embodiment shown in FIG. 5C can be considered a variation of the embodiment shown in FIG. 5A. In the embodiment of FIG. 5C, a single side conduit is implemented instead of having two side conduits as shown in FIG. 5A. In the embodiment shown by FIG. 5C, dispenser body 531″ includes second side conduit 565 having second cavity 567 and second connector channel 569 connecting second cavity 567 to dispense chamber 541. Acoustic sensor 560 can be disposed in second cavity 567 and can sense sound within dispense chamber 541. Dispenser body 531″ does not have a first side conduit. Thus, sound generator 550 can be disposed in first cavity 557″ in dispensing chamber portion 540 and can generate sound to induce acoustic resonance within dispensing chamber 541.

[0043] According to one embodiment, a liquid dispenser can be designed to avoid Helmholtz resonance caused by the structure of the cavity for accommodating the sound generator and / or acoustic sensor and the connecting channel. In one aspect, to avoid the Helmholtz resonator structure, the width of the cavity and the width of the connector channel can be maintained substantially the same. In one aspect, to avoid Helmholtz resonance caused by the side conduit, the implementation of the side conduit can be avoided. In one example, the sound generator and acoustic sensor can be disposed within the dispense chamber portion of the liquid dispenser. For example, by selecting a sound generator and acoustic sensor small enough to fit within the dispense chamber portion of the liquid dispenser, a side conduit protruding from the dispense chamber portion is unnecessary, thereby avoiding Helmholtz resonance that may be caused by the structure of the side conduit. Avoiding Helmholtz resonance can reduce distortions that occur when detecting tip-liquid contact. Furthermore, avoiding Helmholtz resonance can improve the accuracy of liquid volume sensing and / or tip presence detection.

[0044] FIG. 6 is an exemplary diagram illustrating a cross-sectional view of an exemplary liquid dispenser 630 for avoiding acoustic resonance within a frequency range of sound sensed by an acoustic sensor of the liquid dispenser 630, according to embodiments herein. The exemplary liquid dispenser 630 of FIG. 6 is configured to avoid Helmholtz resonator structures that can generate undesirable acoustic resonance and may not have a side conduit. In one embodiment, the liquid dispenser 630 may be an embodiment of the liquid dispenser 330. In the embodiment shown in FIG. 6, the liquid dispenser 630 includes a dispenser body 631 including a dispense chamber portion 640 and a piston chamber portion 675. The dispense chamber portion 640 has a dispense chamber 641 therein. The dispense chamber 641 may have a first opening at a first portion 643 of the dispense chamber 640 and a second opening at a second portion 645 of the dispense chamber 640. The first portion 643 of the dispense chamber 641 is coupled to a dispense tip 647. Dispense chamber 641 is connected to piston chamber 677 of piston chamber portion 675 through a second opening in second portion 645. Piston chamber 677 is configured to direct piston 670 in linear motion within piston chamber 677 to draw liquid into liquid dispenser 630 and dispense liquid out of liquid dispenser 630 (e.g., via dispensing tip 647). Liquid can be drawn into tip cavity 649 of dispensing tip 647 and dispensed out of tip cavity 649 based on the movement of piston 670.

[0045] As shown in FIG. 6 , dispensing chamber 641 may have a longitudinal path extending longitudinally between a first opening of first portion 643 and a second opening of second portion 645. Sound generator 650 may be positioned within dispensing chamber 641 to provide sound to the longitudinal path of dispensing chamber 641. In one embodiment, acoustic sensor 660 may be positioned within dispensing chamber 641 to sense sound directly from the longitudinal path of dispensing chamber 641. In the example shown in FIG. 6 , sound generator 650 and acoustic sensor 660 are located on the same side of dispenser body 631. However, the location of sound generator 650 relative to the location of acoustic sensor 660 is not limited to the example shown in FIG. 6 . In one embodiment, sound generator 650 and / or acoustic sensor 660 may not protrude from dispensing chamber portion 641.

[0046] As shown in FIG. 6 , dispenser body 631 of liquid dispenser 630 has first cavity 657 and first connector channel 659 connecting first cavity 657 to dispense chamber 641. Sound generator 650 may be disposed in first cavity 657 and may generate sound to induce acoustic resonance in dispense chamber 641. Dispenser body 631 includes second cavity 667 and second connector channel 669 connecting first cavity 657 and dispense chamber 647. Acoustic sensor 660 may be disposed in second cavity 667 and may sense sound in dispense chamber 641. Because the width of first cavity 657 and the width of first connector channel 659 are substantially the same, first cavity 657 and first connector channel 659 do not form a Helmholtz resonator. Thus, there are no Helmholtz resonances in the liquid dispenser 630, and thus errors caused by such acoustic resonances may be reduced or eliminated. As discussed in detail below, resonances based on the length L of the first connector channel 659 may be calculated differently. Similarly, when the width of the second cavity 667 and the width of the first connector channel 669 are substantially the same, the first cavity 667 and the first connector channel 669 also do not form a Helmholtz resonator.

[0047] 7 shows a calculation of the resonant frequency of sound in the connecting channel between the cavity and the dispense chamber when the width of the cavity and the connecting channel are substantially the same. In one embodiment, first cavity 557 and first connecting channel 559 of liquid dispenser 530 of FIG. 5A can have a structure similar to cavity 757 and connecting channel 759, respectively, of FIG. 7. In one embodiment, second cavity 567 can have a structure similar to first cavity 557, and there can be a connecting channel connected to second cavity 567, similar to connecting channel 559.

[0048] 7, connecting channel 759 has a neck length L. In one embodiment, a sound generator may be disposed within cavity 757, and neck length L may represent the distance between the sound generator and the dispensing chamber. Where c represents the speed of sound and n represents the harmonic number, the resonant frequency f at connecting channel 759 may be calculated based on the following equation:

number

[0049] For example, as discussed above, the desired frequency range for detecting tip-liquid contact may be 200 Hz to 1 kHz, or preferably 100 Hz to 4 kHz. In such an example, the resonant frequency f is preferably outside the range of 100 Hz to 4 kHz. When the harmonic number is 1 and the resonant frequency f is 4 kHz, the neck length L is approximately 21 mm. Therefore, to ensure that the resonant frequency f is greater than 4 kHz, outside the range of 100 Hz to 4 kHz, when the harmonic number is 1, the neck length L should be less than 21 mm. In other words, a shorter neck length L may be preferred to ensure that the resonant frequency f is outside the desired frequency range for detecting tip-liquid contact.

[0050] FIG. 8A shows experimental acoustic spectra based on liquid dispensers with very short or no connecting channels. In the embodiment shown in FIG. 8A, when the neck length L of the connecting channel is approximately 0 mm, the difference in acoustic signal magnitude between the "tip open" state (before contacting liquid) and the "tip closed" state (when in contact with liquid) is 11.9 dB at approximately 900 Hz. FIG. 8B shows experimental results based on a liquid dispenser with a connecting channel having a medium length. FIG. 8B shows that when the neck length L of the connecting channel is approximately 12 mm, the difference in acoustic signal magnitude between the "tip open" state (before contacting liquid) and the "tip closed" state (when in contact with liquid) is 9.35 dB at approximately 900 Hz, which is smaller than the difference in acoustic signal magnitude observed in FIG. 8A. FIG. 8C shows experimental results based on a liquid dispenser with a long connecting channel. Figure 8C shows that when the neck length L of the connecting channel is approximately 25 mm, the difference in acoustic signal magnitude between the "tip open" state (before contacting liquid) and the "tip closed" state (when in contact with liquid) is 8.3 dB at approximately 900 Hz, which is smaller than the difference in acoustic signal magnitude observed in Figures 8A and 8B.

[0051] As discussed above, when the harmonic number is 1, the neck length L should be less than 21 mm to ensure that the resonant frequency f is greater than 4 kHz, which is outside the 100 Hz to 4 kHz range. A neck length L slightly greater than 21 mm in Figure 8C may interfere with the measurement of the acoustic signal because the resonant frequency f may be in the 100 Hz to 4 kHz range. This interference, caused by a neck length L of 25 mm, may result in a smaller magnitude difference between the "tip open" and "tip closed" states than when the neck length L is approximately 0. A neck length L much greater than 21 mm in Figure 8C may interfere with the measurement of the acoustic signal even more than in Figure 8B because the resonant frequency f is in the 100 Hz to 4 kHz range. As shown in Figures 8A-8C, tip-liquid contact detection decreases as the neck length L increases (e.g., beyond 21 mm) to the point where the resonant frequency f is within the frequency range for detecting tip-liquid contact.

[0052] Furthermore, as shown in FIGS. 8A-8C , the magnitude of the acoustic signal when a tip is absent (e.g., the "no tip" state) becomes more similar to the magnitude of the acoustic signal when a tip is present (e.g., the "tip open" state and the "tip closed" state) as the neck length L of the connecting channel increases. Thus, the magnitude of the acoustic signal when a tip is absent becomes less distinguishable from the magnitude of the acoustic signal when a tip is present as the neck length L of the connecting channel increases. In particular, the frequency range for detecting whether a tip is present on a liquid dispenser may be 200 Hz to 1 kHz, or preferably 100 Hz to 4 kHz. Thus, as the neck length L of the connecting channel increases (e.g., beyond 21 mm) to the point where the resonant frequency f is within the frequency range for detecting tip presence, detection of tip presence at the dispenser decreases. Thus, as discussed above, a long neck length L may be undesirable, and reducing or eliminating side conduits can provide improved results with reduced errors in tip-liquid contact detection and / or tip presence detection.

[0053] FIG. 9A is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 930 for avoiding acoustic resonance within a frequency range of sound sensed by an acoustic sensor of the liquid dispenser 930, according to one embodiment herein. FIG. 9AA is an exemplary diagram showing a calculation of the acoustic resonance frequency in the connecting channel between the cavity and the dispense chamber for the embodiment shown in FIG. 9A. The exemplary liquid dispenser 930 of FIG. 9A is configured to avoid a Helmholtz resonator structure that can create undesirable acoustic resonance and may not have a side conduit. In FIG. 9A, portions represented by reference numerals 935, 940, 941, 943, 945, 947, 949, 970, 975, and 977 have similar features to portions represented by reference numerals 640, 641, 643, 645, 647, 649, 670, 675, and 677, respectively, discussed above with reference to FIG. 3. Therefore, detailed discussion of reference numbers 935, 940, 941, 943, 945, 947, 949, 970, 975, and 977 will be omitted.

[0054] As shown in FIG. 9A , sound generator 950 may be positioned within first cavity 957 of dispense chamber 941 to provide sound to the longitudinal path of dispense chamber 941. Acoustic sensor 960 may be positioned within second cavity 967 of dispense chamber 941 to sense sound directly from the longitudinal path of dispense chamber 941. In the example shown in FIG. 9A , sound generator 950 and acoustic sensor 960 are located on the same side. Dispenser body 931 of liquid dispenser 930 may also have a first connector channel 959 connecting first cavity 957 to dispense chamber 941. Because the widths of first cavity 957 and first connector channel 959 are substantially the same, first cavity 957 and first connector channel 959 do not form a Helmholtz resonator. Similarly, because the width of the second cavity 967 and the width of the second connector channel 969 are substantially the same, the second cavity 967 and the second connector channel 969 do not form a Helmholtz resonator. Therefore, there is no Helmholtz resonance in the liquid dispenser 930, and thus errors caused by such acoustic resonance may be reduced or eliminated.

[0055] The resonant frequency formed by the cavities (e.g., first cavity 957 and second cavity 967), as discussed above, is given by the equation:

number

[0056] 10A is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 1030 for avoiding acoustic resonances within a frequency range of sound sensed by an acoustic sensor of the liquid dispenser 1030, according to one embodiment herein. FIG. 10AA is an exemplary diagram showing a calculation of sound resonant frequencies in a connecting channel between a cavity and a dispense chamber for the embodiment shown in FIG. 10A. The exemplary liquid dispenser 1030 of FIG. 10A is configured to avoid Helmholtz resonator structures that may create undesirable acoustic resonances and may have no side conduits. In Figure 10A, the portions represented by reference numerals 1035, 1040, 1041, 1043, 1045, 1047, 10410, 1070, 1075, and 1077 have similar features to the portions represented by reference numerals 640, 641, 643, 645, 647, 6410, 670, 675, and 677, respectively, discussed above with reference to Figure 6. Accordingly, a detailed discussion of reference numerals 1035, 1040, 1041, 1043, 1045, 1047, 1049, 1070, 1075, and 1077 will be omitted.

[0057] As shown in FIG. 10A , sound generator 1050 may be positioned within first cavity 1057 of dispense chamber 1041 to provide sound to the longitudinal path of dispense chamber 1041. Acoustic sensor 1060 may be positioned within second cavity 1067 of dispense chamber 1041 to sense sound directly from the longitudinal path of dispense chamber 1041. In the example shown in FIG. 10A , sound generator 1050 and acoustic sensor 1060 are located on opposite sides. Dispenser body 1031 of liquid dispenser 1030 may also have first connector channel 1059 connecting first cavity 1057 to dispense chamber 1041. Because the widths of first cavity 1057 and first connector channel 1059 are substantially the same, first cavity 1057 and first connector channel 1059 do not form a Helmholtz resonator. Similarly, because the width of the second cavity 1067 and the width of the second connector channel 1069 are substantially the same, the second cavity 1067 and the second connector channel 1069 do not form a Helmholtz resonator. Thus, there are no Helmholtz resonances in the liquid dispenser 1030, and thus errors caused by such acoustic resonances may be reduced or eliminated.

[0058] The resonant frequency formed by the cavities (e.g., the first cavity 1057 and the second cavity 1067), as discussed above, is given by the equation:

number

[0059] FIG. 11A is an exemplary diagram showing a cross-sectional view of an exemplary liquid dispenser 1130 with a side conduit structured to avoid acoustic resonance within the frequency range of sound sensed by the liquid dispenser's acoustic sensor, according to one embodiment herein. FIG. 11AA is an exemplary diagram showing a calculation of the acoustic resonance frequency in the connecting channel between the cavity and the dispense chamber for the embodiment shown in FIG. 11A. In FIG. 11A, portions represented by reference numerals 1135, 1140, 1141, 1143, 1145, 1147, 1149, 1170, 1175, and 1177 have similar features to portions represented by reference numerals 340, 341, 343, 345, 347, 349, 370, 375, and 377, respectively, discussed above with reference to FIG. 3. Therefore, detailed discussion of reference numbers 1135, 1140, 1141, 1143, 1145, 1147, 1149, 1170, 1175, and 1177 will be omitted.

[0060] 11A , liquid dispenser 1130 has a dispenser body 1131 including a first side conduit 1155 having a first cavity 1157 and a first connector channel 1159 connecting first cavity 1157 to dispense chamber 1141. Sound generator 1150 may be disposed within first cavity 1157 and may generate sound to induce acoustic resonance within dispense chamber 1141. Dispenser body 1131 includes a second side conduit 1165 having a second cavity 1167 and a second connector channel 1169 connecting second cavity 1167 to dispense chamber 1141. Acoustic sensor 1160 may be disposed within second cavity 1167 and may sense sound within dispense chamber 1141. 11A , the widths of the first connector channel 1159 and the second connector channel 1169 are substantially the same as the widths of the first cavity 1157 and the second cavity 1167, respectively. Therefore, the first cavity 1157 and the first connector channel 1159 do not form a Helmholtz resonator, and the second cavity 1167 and the second connector channel 1169 do not form a Helmholtz resonator either. The arrangement of the sound generator 1150 and the acoustic sensor 1160, as well as the number of side conduits implemented, may not be limited to the example shown in FIG. 11A . For example, in another example, the sound generator and the acoustic sensor may be disposed within a single side conduit.

[0061] The resonant frequency formed by the cavities (e.g., the first cavity 1157 and the second cavity 1167), as discussed above, is given by the equation:

number

[0062] FIG. 12 is an exemplary diagram illustrating a liquid dispenser system 1200, including a cross-sectional view of the liquid dispenser, according to embodiments herein. The liquid dispenser system 1200 includes a liquid dispenser 1230 controlled by the controller 110. The liquid dispenser 1230 shown in FIG. 12 has a similar structure to the liquid dispenser 1030 of FIG. 10A , and therefore the structural details of the liquid dispenser 1230 are similar to the structural details of the liquid dispenser 1030 discussed above. Although FIG. 12 illustrates that the liquid dispenser 1230 has a similar structure to that of the liquid dispenser 1030, the structure of the liquid dispenser 1230 is not limited to that of the liquid dispenser 1030, and another type of liquid dispenser, such as the liquid dispenser 530 of FIG. 5A or the liquid dispenser 630 of FIG. 6 or the liquid dispenser 930 of FIG. 9A or the liquid dispenser 1130 of FIG. 11A , can be used as the liquid dispenser 1230. Liquid dispenser system 1200 further includes a liquid dispenser transport device 1285 configured to drive liquid dispenser 1230 and a piston driver 1280 configured to drive piston 1270 of liquid dispenser 1230. For example, controller 110 can control liquid dispenser transport device 1285 to move liquid dispenser 1230 toward liquid 1290 stored in reservoir 1295. Controller 110 can control sound generator 1250 to generate sound and can utilize acoustic sensor 1260 to sense sound within the dispense chamber of liquid dispenser 1230. If controller 110 determines, based on the sensed sound, that contact between dispensing tip 1247 and liquid 1290 has occurred, controller 110 can control liquid dispenser transport device 1285 to stop the movement of liquid dispenser 1230, and controller 110 can control piston driver 1280 to drive piston 1270 to draw liquid into dispensing tip 1247. As discussed above, detection of tip-liquid contact by liquid dispenser system 1200 is improved using embodiments such as liquid dispenser 530, liquid dispenser 630, liquid dispenser 930, liquid dispenser 1030, and liquid dispenser 1130.

[0063] According to one aspect of the present disclosure, an acoustic filter may be implemented between a dispense chamber of a liquid dispenser and a piston chamber of the liquid dispenser, the acoustic filter configured to separate the dispense chamber from the piston chamber. As discussed above, piston movement can cause additional noise or changes in acoustic characteristics within the dispense chamber, which can affect the sound sensed by the acoustic sensor. For example, noise, such as noise from a motor that moves the piston or noise from the piston moving within the piston chamber, can adversely affect tip-liquid contact detection and / or liquid volume sensing. Furthermore, the piston can define an enclosed portion of the piston chamber, which is the portion of the piston chamber surrounded by the piston and connected to the dispense chamber. Because the position of the piston within the piston chamber can define the volume of the enclosed portion, the volume of the enclosed portion of the piston chamber can change based on piston movement. Changes in the volume of the enclosed portion can also affect the sound sensed by the acoustic sensor. Implementing an acoustic filter that can acoustically separate the dispense chamber from the piston chamber can reduce or eliminate errors caused by piston movement.

[0064] The acoustic filter disposed between the piston chamber and the dispense chamber should be configured to allow air to move between the piston chamber and the dispense chamber. In one embodiment, the acoustic filter may be a sound-absorbing filter configured to muffle sound from the piston chamber (e.g., noise from piston movement). The sound-absorbing acoustic filter may be made of an air-permeable material to allow air to pass through the acoustic filter between the piston chamber and the dispense chamber. The sound-absorbing filter may be made of an open-cell foam material (e.g., polyurethane), a fibrous material (e.g., glass wool), or a porous material.

[0065] In one embodiment, the acoustic filter may be a sound-reflecting filter structured to separate the length of the air column resonance of the dispense chamber from the length of the air column resonance of the piston chamber, which changes with piston movement. The sound-reflecting filter may not be air-permeable. Thus, when a sound-reflecting filter is used as the acoustic filter, an air passage is also implemented with the acoustic filter to allow air to pass between the piston chamber and the dispense chamber via the air passage. In one embodiment, the sound-reflecting filter may be made of closed-cell foam (e.g., polyethylene) with an air passage so that air can pass through the acoustic filter between the piston chamber and the dispense chamber via the air passage. In one embodiment, the foam may be configured with a thickness that allows it to compressively conform to the piston chamber during piston movement without impeding the passage of air. In one embodiment, the sound-reflecting filter may be made of a flexible material. In this aspect, an air passage may be formed as a result of a change in shape (e.g., contraction) of the sound-reflecting filter due to a pressure differential induced by piston movement.

[0066] FIG. 13 is an exemplary diagram illustrating an exemplary acoustic filter implemented in a liquid dispenser, according to embodiments herein. FIG. 13 illustrates a liquid dispenser 1330 controlled by controller 110. Liquid dispenser 1330 may be similar to dispenser 230 of FIG. 2. Liquid dispenser 1330 may include a dispenser body 1331 including a dispense chamber portion 1340 having a dispense chamber 1341 and a piston chamber portion 1375 having a piston chamber 1377. Dispense chamber 1341 has a first opening in a first portion 1343 of dispense chamber portion 1340 and a second opening in a second portion 1345 of dispense chamber portion 1340. Piston chamber 1377 is connected to dispense chamber 1341 through a second opening in second portion 1345. Dispense chamber body 1331 may be contained within housing 1335, which may be of optional construction. Liquid dispenser 1330 further includes a piston 1370 that is received and guided by a piston chamber 1375. First portion 1343 is configured to mate with a dispensing tip, such as dispensing tip 1347. Dispensing tip 1347 may be permanently attached to first portion 1343 or may be removably attached to first portion 1343.

[0067] 13, acoustic filter 1379 is disposed between piston chamber 1377 and dispense chamber 1341. In one embodiment, acoustic filter 1379 may be configured such that acoustic filter 1379 can acoustically isolate dispense chamber 1341 from piston chamber 1377. Additionally, acoustic filter 1379 may be configured to allow air to pass between piston chamber 1377 and dispense chamber 1341 (e.g., having a rough surface texture) such that movement of piston 1370 can draw in or dispense liquid.

[0068] In one embodiment, the acoustic filter 1379 can substantially improve the results of liquid volume sensing, where the liquid volume is sensed based on the sound sensed by the acoustic sensor. FIG. 14A is an exemplary diagram showing a plot illustrating the frequency spectrum of an acoustic signal at various piston positions (PL) in the piston chamber and different liquid levels in the dispenser tip, according to an embodiment without an acoustic filter. FIG. 14B is an exemplary diagram showing a plot illustrating the frequency spectrum of an acoustic signal at various piston positions (PL) in the piston chamber and different liquid levels in the dispenser tip, according to an embodiment with an acoustic filter. In the embodiment shown in FIG. 14A when the acoustic filter is not implemented, the frequency spectrum changes significantly based on the position of the piston. As discussed above, the change in frequency spectrum based on piston position is due to the change in the volume of the enclosed area in the piston chamber. In contrast, in the embodiment shown in FIG. 14B when the acoustic filter is implemented, the position of the piston has little effect on the frequency spectrum. Therefore, by implementing an acoustic filter, the effect of piston position on the acoustic spectrum for liquid volume sensing can be reduced or eliminated.

[0069] In one embodiment, different types of acoustic filters can produce different effects. As discussed above, the acoustic filter can be a closed-cell filter or an open-cell filter. In some cases, a closed-cell filter (e.g., made of polyethylene) can provide more advantages than an open-cell filter (e.g., made of polyurethane). FIG. 15A is an exemplary diagram showing the acoustic spectrum at different thicknesses of an acoustic filter made of polyethylene (PE). In the embodiment shown in FIG. 15A, the position of the piston has little effect on the acoustic spectrum, regardless of whether the acoustic filter is thin (e.g., 5 mm) or thick (e.g., 10 mm). FIG. 15B is an exemplary diagram showing the acoustic spectrum at different thicknesses of an acoustic filter made of polyurethane (PU). In the embodiment shown in FIG. 15B, the piston position has some effect on the acoustic spectrum when the acoustic filter is thick (e.g., 10 mm), and the piston position has a large effect on the acoustic spectrum when the acoustic filter is thin (e.g., 5 mm). Therefore, in some instances of the embodiment illustrated by Figures 15A and 15B, it may be preferable to utilize a closed-cell filter as the acoustic filter.

[0070] An acoustic filter implemented between the dispense chamber and the piston chamber acoustically isolates the dispense chamber from the piston chamber, so that changes in the volume of the enclosed portion of the piston chamber have little or no effect on the frequency of the sound sensed by the acoustic sensor. A change in the air column length also changes the acoustic resonance frequency. When an acoustic filter is implemented, the resonance frequency of the sound sensed by the acoustic sensor depends on the air column length of the dispense chamber and the dispense tip. The air column length in the dispense chamber and the dispense tip changes based on the liquid volume in the dispense tip. Therefore, the liquid volume in the dispense tip can be estimated based on the resonance frequency of the sound sensed by the acoustic sensor. The correlation between frequency and volume can be established via a lookup table. For example, the lookup table can show a one-to-one relationship between the measured resonance frequency and liquid volume for a given type of dispense tip (e.g., a 350 μl dispense tip or a 1000 μl dispense tip). Furthermore, the dispense tip may not be properly coupled to the liquid dispenser. In such cases, the frequency of the sound detected may be different from the frequency of the sound detected when the dispensing tip is properly coupled to the liquid dispenser. By monitoring the frequency of the sound, the controller 110 can determine whether the dispensing tip is properly coupled to the liquid dispenser.

[0071] In some embodiments, by monitoring the resonant frequency and loudness within the dispensing chamber, the controller 110 can determine what type of dispensing tip is coupled to the liquid dispenser and / or if no tip is coupled.

[0072] Figure 16A is an exemplary diagram showing that different liquid levels in the dispensing tip correspond to different frequencies when the acoustic filter is 5 mm thick. Figure 16B is an exemplary diagram showing that different liquid levels in the dispensing tip correspond to different frequencies when the acoustic filter is 10 mm thick. Both Figures 16A and 16B show that the frequency increases as the liquid level in the dispensing tip increases. Figure 16B shows that a thicker acoustic filter provides slightly more consistent results, regardless of the piston position.

[0073] Furthermore, because the sensed sound may change based on volume changes within the dispensing tip, different types of dispensing tips can be identified based on the sound sensed by the acoustic sensor. For example, arrays of sound frequency spectra for various types of dispensing tips can be included in multiple lookup tables. Thus, the controller 110 can identify the type of dispensing tip if the measured spectrum matches a spectrum stored in the corresponding lookup table.

[0074] 17 is an exemplary diagram illustrating a liquid dispenser system 1700, including a cross-sectional view of the liquid dispenser, according to embodiments herein. Liquid dispenser system 1700 includes a liquid dispenser 1730 controlled by controller 110. Liquid dispenser 1730 includes an acoustic filter 1779 disposed between a dispense chamber 1741 and a piston chamber 1777. With the exception of acoustic filter 1779, liquid dispenser 1730 shown in FIG. 17 has a similar structure to liquid dispenser 1030 of FIG. 10A , and therefore, the structural details of liquid dispenser 1730 are similar to the structural details of liquid dispenser 530 discussed above. 17 shows that liquid dispenser 1730 has a structure similar to that of liquid dispenser 530 equipped with acoustic filter 1779, the structure of liquid dispenser 1730 is not limited to that of liquid dispenser 530, and another type of liquid dispenser, such as liquid dispenser 530 of FIG. 5A or liquid dispenser 630 of FIG. 6 or liquid dispenser 930 of FIG. 9A or liquid dispenser 1130 of FIG. 11A, can be used as liquid dispenser 1730 equipped with acoustic filter 1779. Liquid dispenser system 1700 further includes a liquid dispenser transport device 1785 configured to drive liquid dispenser 1730 and a piston driver 1780 configured to drive piston 1770 of liquid dispenser 1730. For example, controller 110 can control liquid dispenser transport device 1785 to move liquid dispenser 1730 toward liquid 1790 stored in reservoir 1795. Controller 110 can control sound generator 1750 to generate a sound and can utilize acoustic sensor 1760 to sense sound within dispense chamber 1741 of liquid dispenser 1730. If controller 110 determines, based on the detected sound, that contact between dispensing tip 1747 and liquid 1790 has occurred, controller 110 can control liquid dispenser transport device 285 to stop movement of liquid dispenser 1730, and controller 110 can control piston driver 1780 to drive piston 1770 to draw liquid into dispensing tip 1747.As described above, acoustic filter 1779 acoustically isolates dispense chamber 1741 from piston chamber 1777 so that movement of piston 1770 has little or no effect on the sound sensed by acoustic sensor 1760.

[0075] According to another aspect, improved methods for processing sound sensed by an acoustic sensor are desired to accurately detect tip-liquid contact. As noted above, detecting tip-liquid contact based on changes in the amplitude / phase or acoustic impedance of the sensed sound can introduce undesirable errors (e.g., due to ambient noise or another anomaly that generates an error event). For example, detecting tip-liquid contact based on amplitude / phase or acoustic impedance typically suffers from false positive errors, and the rate of false positive errors increases with increasing background acoustic noise.

[0076] FIG. 18 is an exemplary diagram illustrating false positive errors due to white noise when detecting tip-liquid contact using sound amplitude. The diagram in FIG. 18 shows experimental results as a graph of sound amplitude over time. The dashed-dotted line on the graph indicates the amplitude threshold for determining whether tip-liquid contact has occurred. In this experiment, actual tip-liquid contact occurred at 2000 ms. As shown by the solid line in FIG. 18, when only ambient noise (e.g., 65 dBc ambient noise) is present in the background, the sound amplitude exceeds the amplitude threshold only at approximately 2000 ms, and therefore, the controller 110 detects tip-liquid contact only at 2000 ms. On the other hand, as shown by the dashed line in FIG. 18, when white noise (e.g., 85 dBc white noise) is present in the background, the sound amplitude appears noisy, and as indicated by the arrows, the sound amplitude exceeds the amplitude threshold twice before exceeding the threshold again at the 2000 ms mark. Thus, the diagram in Figure 18 shows that when sound amplitude at a single frequency is used to detect tip-liquid contact, false positive errors increase as background acoustic noise increases.

[0077] FIG. 19 is an example diagram illustrating false positive errors due to single-tone noise when detecting tip-liquid contact using sound amplitude at the same frequency. The diagram in FIG. 19 shows experimental results as a graph of sound amplitude over time. The dashed-dotted line on the graph indicates the amplitude threshold for determining whether tip-liquid contact occurred. In this experiment, actual tip-liquid contact occurred at approximately 2000 ms. As shown by the solid line in FIG. 19, when only ambient noise is present in the background, the sound amplitude exceeds the amplitude threshold only at approximately 2000 ms. On the other hand, as shown by the dashed line in FIG. 19, when the background noise is single-tone noise with a frequency of 430 Hz and 90 dBC, the sound amplitude at 430 Hz drops significantly below the threshold between 1100 ms and 1700 ms, as indicated by the arrow, then rises sharply and falls below the threshold again at the 2000 ms mark, when actual contact occurred.

[0078] In the presence of background noise, the acoustic intensity of the sound generator can be increased to reduce the importance of the background noise. However, this approach has the limitation that certain types of background noise still have a significant impact, even when the acoustic intensity of the sound generator is increased. Furthermore, increasing the acoustic intensity can have negative effects such as higher power consumption, increased temperature of the sound generator and / or controller 110, increased total harmonic distortion, and reduced lifespan of the sound generator and / or acoustic sensor. FIG. 20 shows an exemplary diagram illustrating false detection errors due to airflow noise. During the experiment in FIG. 20, the sound amplitude was set at an 8.2x gain on the sound generator. In the embodiment shown in FIG. 20, when strong airflow was introduced around the liquid dispenser, thus adding substantial background noise, increasing the acoustic intensity of the sound generator was not enough to prevent the wind noise of the airflow from causing many false detection errors.

[0079] According to one aspect of the present disclosure, instead of monitoring the amplitude / phase or acoustic impedance of the sensed sound, the acoustic intensity or acoustic power of the sensed sound can be monitored to detect whether the tip of a liquid dispenser has contacted a liquid. In one embodiment, values ​​associated with the acoustic power or acoustic intensity can be averaged over a time window and the average value can be monitored to detect tip-liquid contact.

[0080] The sound power SP can be calculated based on the following formula, where A is the area perpendicular to the sound wave propagation, I is the sound intensity, p is the sound pressure, and Z0 is the characteristic acoustic impedance:

number

[0081] Assuming that the area A and the characteristic acoustic impedance Z0 are constant, the sound power SP is calculated by multiplying the squared sound pressure p 2 The acoustic sensor detects sound pressure and generates a voltage amplitude that corresponds to the sound pressure.

number

number

number

number

[0082] 21 shows a flow diagram of an exemplary method 2100 for detecting contact between a dispenser and a liquid. Method 2100 may be implemented, for example, by control circuitry 111 of controller 110. In one embodiment, the method may begin at step or operation 2101, in which control circuitry 111 obtains, via an acoustic sensor, a plurality of voltage values ​​associated with sound sensed by the acoustic sensor within a time window. In operation 2103, control circuitry 111 squares each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window. In operation 2105, control circuitry 111 calculates an average value of the plurality of squared voltage values ​​for the time window. In operation 2107, control circuitry 111 determines whether contact between the liquid dispenser and the liquid occurred during the time window based on the average value of the plurality of squared voltage values.

[0083] For example, according to one embodiment, an acoustic sensor senses sound and generates a voltage value associated with the sensed sound within a time window. The controller 110 obtains the voltage values ​​of the voltage output from the acoustic sensor over a set time window, squares each voltage value, and then determines an average value of the squared voltage values ​​over the set time window. The average value of the squared voltages can be used to determine whether the tip of the liquid dispenser contacted liquid during the time window.

[0084] In one embodiment, the control circuit 111 may acquire multiple voltage values ​​over the time domain. In one embodiment, the control circuit 111 may acquire multiple voltage values ​​over the frequency domain. In such an embodiment, the multiple voltage values ​​may be acquired over a predetermined frequency band including multiple frequencies. In one embodiment, the predetermined frequency band may have a bandwidth greater than 1 kHz.

[0085] For example, the voltage values ​​may be acquired over the time domain and / or the frequency domain. When the voltage values ​​are acquired over the frequency domain, the voltage values ​​may be acquired over a wide frequency band (e.g., 200 Hz to 1 kHz, or preferably 100 Hz to 4 kHz).

[0086] Signals monitored at a single frequency can introduce errors. Errors can be reduced by monitoring signals across a frequency band (e.g., across multiple frequencies) rather than a single frequency. In one example, a value associated with the average power across a frequency band (e.g., 200 Hz to 1 kHz or 100 Hz to 4 kHz) is used to detect tip-liquid contact. From a signal processing perspective, sampling multiple data samples across multiple frequencies in a frequency band is the same as sampling multiple data samples at multiple time points across a time window. However, monitoring signals monitored across a time window may be a preferred method because it requires less complex hardware and algorithms for detection purposes.

[0087] In one example, considering a frequency band of 100 Hz to 4 kHz, the preferred time window and number of samples are as follows: The upper limit of the frequency band can be set to half the sampling rate of the acoustic sensor. If the acoustic sensor's sample rate (S) is 8 kHz, the upper limit of the frequency band is 4 kHz (0.5 S). A total of 80 (N) samples generates a time window of 10 milliseconds (N / S). This allows the lower limit of the frequency band to be set to 100 Hz. The corresponding frequency band resolution is also (frequency × 2) / N = 100 Hz, which is considered suitable for detection purposes. On the other hand, to obtain a more relaxed lower limit (e.g., 200 Hz or higher), the time window can be less than 5 milliseconds. For a given time window, a higher sample rate (e.g., 16 kHz, 48 kHz, 96 kHz, etc.) may be preferred because collecting more samples provides more data for averaging, thereby reducing the overall noise.

[0088] In one embodiment, the sound sensed by the acoustic sensor may be sensed from sound traveling within the liquid dispenser. For example, the acoustic sensor may sense sound traveling within the liquid dispenser 130, such as within the dispense chamber of the liquid dispenser. Sound traveling within the liquid dispenser may include sound resulting from sound generated by a sound generator within the liquid dispenser. The generated sound may be a single-tone signal, a multi-tone signal, white noise, pink noise, etc. In one embodiment, sound traveling within the liquid dispenser may include sound resulting from sound generated by a sound generator located external to the liquid dispenser and / or a sound generator located within the liquid dispenser.

[0089] In one example, before engaging in any type of detection, the controller 110 can control the sound generator to generate a pilot tone to induce a desired resonance. In this manner, a discernible change in sound amplitude occurs at the desired resonance frequency when tip-liquid contact occurs. The pilot tone can be a single-tone signal, a multi-tone signal, white noise, pink noise, or the like. In one embodiment, a single-tone signal can provide an optimal signal-to-noise ratio (SNR) in tip-liquid detection. In such an embodiment, the single-tone signal needs to match the mechanical resonance of the dispense chamber to achieve optimal results. Thus, in such an embodiment, when a single-tone signal is used, different tip types may require single-tone signals with different frequencies.

[0090] In one embodiment, the control circuit 111 in operation 2107 determines whether contact with liquid has occurred by determining that contact with liquid has occurred when the average value of the multiple squared voltage values ​​is less than a threshold value, and determining that contact with liquid has not occurred when the average value of the multiple squared voltage values ​​is greater than or equal to the threshold value.

[0091] For example, the controller 110 can determine whether the tip of the liquid dispenser contacted the liquid during a time window based on the average value of the squared voltage values. In particular, the controller 110 can determine that the tip contacted the liquid during the time window if the average value is below a threshold, and can determine that the tip did not contact the liquid if the average value is equal to or greater than the threshold.

[0092] In one example, the size of the time window may be 20 milliseconds or more. For example, if the time window is set to 20 milliseconds, the controller 110 can determine whether the tip has contacted the liquid every 20 milliseconds. Considering a scenario in which the acoustic signal is sampled by the acoustic sensor at 48 kHz, if the time window is 20 milliseconds, 960 samples are collected every 20 milliseconds, and therefore the average value is calculated once every 960 samples.

[0093] In one embodiment, at least one of the acoustic sensor or the sound generator that is the source of the sensed sound is located inside the liquid dispenser. For example, as shown in various figures, such as Figures 2, 3, 5, and 6, the acoustic sensor may be located inside the liquid dispenser and the sound generator may be located inside or outside the liquid dispenser. In a preferred embodiment, the acoustic sensor may be located inside the liquid dispenser, while the sound generator may be located either inside or outside the liquid dispenser.

[0094] In further embodiments, the structures, devices, and methods discussed herein may be further used for additional sensing operations. Structural proposals regarding cavities may be further used in any of the following embodiments to improve the sensing method.

[0095] In a further embodiment, automated pipetting system 100 may perform a method of tip presence detection, as described with respect to Figures 22-23. The tip presence detection method may be performed using any suitable systems and hardware discussed herein, including any controller (e.g., controller 110), liquid dispensing system (e.g., liquid dispensing systems 100, 200, 298, 1200, 1700), liquid dispenser (e.g., liquid dispenser 130, 230, 330, 530, 580, 590, 630, 930, 1030, 1330), and any or all of their components. However, the tip presence detection method described herein is not limited to the specific hardware and devices discussed herein and may be implemented by any suitable control system and liquid dispensing system. For example, the tip presence detection method may be implemented by a liquid dispensing system described herein in conjunction with a controller, such as controller 110 depicted in FIG. 1B , which may employ any of its components (control circuitry 111, communication interface 113, non-transitory computer-readable medium 115 (e.g., memory or other computer-readable storage medium)) to implement the tip presence detection method. In one embodiment, control circuitry 111 may include one or more processors, programmable logic circuits (PLCs) or programmable logic arrays (PLAs), field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), or any other control circuitry. In a further embodiment, as described with respect to FIG. 1B , for example, controller 110 may include analog-to-digital converter 117 that converts analog signals to digital signals, digital-to-analog converter 119 that converts digital signals to analog signals, and / or signal conditioning circuitry 121 that can manipulate various analog signals so that the analog signals can meet the requirements of their next stage for further processing.

[0096] In one embodiment, a control circuit (e.g., control circuit 111 shown in FIG. 1B ) may determine whether a dispensing tip is properly coupled to a first portion (e.g., 243, or 343, 543, 643, etc., in FIGS. 2A and 2C ) of a dispensing chamber portion (e.g., 240, or 340, 540, 640, etc., in FIGS. 2B and 2D ) based on an average value of multiple squared voltage values ​​and / or directly based on voltage values ​​at a single frequency or multiple frequencies. The dispensing tip may be considered properly coupled to the first portion of the dispensing chamber portion when the dispensing tip is fully coupled to the first portion of the dispensing chamber portion to provide an airtight seal between the dispensing tip and the first portion of the dispensing chamber portion. The average value of the squared voltage of the sound sensed when the dispensing tip is properly coupled to the liquid dispenser may be different from the average value of the squared voltage when the dispensing tip is not properly coupled to the liquid dispenser. By monitoring the average value of the squared voltage, controller 110 can determine whether the dispensing tip is properly coupled to the liquid dispenser. For example, because the liquid dispenser has a larger opening at the portion coupled to the liquid dispenser than the tip opening of the dispensing tip, the average value of the plurality of squared voltage values ​​may be large when the dispensing tip is not properly coupled to the liquid dispenser. Thus, if the relative increase in the average value of the plurality of squared voltage values ​​exceeds a tip presence threshold, the controller 110 can determine that the dispensing tip is not properly coupled to the liquid dispenser. In a further embodiment, the voltage values ​​at one or more frequencies may be compared to a tip detection threshold to determine the presence or absence of a liquid dispensing tip.

[0097] FIG. 22 is an exemplary diagram showing experimentally obtained acoustic spectra for multiple tip conditions. FIG. 22 shows the amplitude response, in dB, of a liquid dispenser system across a frequency range for multiple tip conditions. The acoustic response spectra are displayed for a liquid dispenser without a dispense tip, with a 1000 μl dispense tip, and with a 350 μl dispense tip. As shown in FIG. 22, the patterns of each response spectrum are somewhat similar, but the frequency locations of the amplitude peaks and valleys differ between each tip condition. For example, without a dispense tip, the amplitude peak is at approximately 570 Hz, while the same frequency produces significantly lower responses with a 1000 μl dispense tip and a 350 μl dispense tip. Therefore, differences in amplitude responses at different frequencies can be used to identify the presence and / or type of dispense tip. A system consistent with embodiments herein can compare the acoustic responses of the system at target frequencies to determine the presence or absence of a dispense tip. Examples of such determinations are discussed below.

[0098] 23 shows a flow diagram of a method of tip presence detection consistent with embodiments herein. Method 2300 may be employed in any of the liquid dispenser systems and devices discussed herein. The operations and / or steps of method 2300 may be performed by any suitable control system discussed herein, such as controller 110, or more generally, by a liquid dispenser system discussed herein, such as liquid dispenser systems 100, 200, 298, 1200, 1700. In embodiments, structural improvements to the dispense chamber cavity discussed herein may be applied to liquid dispenser systems and devices employed in method 2300 of tip presence detection.

[0099] Method 2300 is discussed below with respect to signals having a frequency and a voltage. As discussed herein, a signal, such as a test signal or polling signal disclosed below, in a liquid dispenser system is provided to a sound generator of the liquid dispenser system, which generates an acoustic output having a frequency (e.g., frequency components) corresponding to the frequency of the test signal or polling signal, the frequency having a magnitude corresponding to the voltage of the test signal or polling signal (which may be referred to as a test signal voltage). An acoustic sensor detects the acoustic output, and a response signal having a frequency and voltage corresponding to the frequency and magnitude of the acoustic output is provided to a control circuit (e.g., 111) of the liquid dispenser system.

[0100] In operation 2302, the liquid dispenser system is calibrated with no tips attached. An operator may ensure that no dispense tips are attached to the dispense system before performing the calibration step. In one embodiment, calibration operation 2302 includes measuring at least one signal test response, or more generally, a system test response, at a target frequency. The signal response is measured in response to a test signal provided at the target frequency. An appropriate magnitude of the test signal voltage can be selected according to system characteristics to provide an appropriate test signal.

[0101] The target frequency may be selected, for example, based on an analysis of the acoustic spectrum of the liquid dispenser system under multiple tip conditions. The acoustic spectrum may be collected according to multiple expected tip conditions for the liquid dispenser system. For example, the acoustic spectrum may include an acoustic spectrum for each expected tip condition, including a no-tip condition and a tip-present condition, for a liquid dispenser tip that may be expected to be used. As used herein, a no-tip condition refers to a condition in which no dispense tip is attached to the liquid dispenser system. A tip-present condition refers to a condition in which a liquid dispenser tip is attached to the liquid dispenser system. In embodiments, the acoustic spectrum may include only a subset of the expected tip conditions. The target frequency may be selected, for example, according to a frequency that shows a significant difference between the no-tip condition and one or more tip-present conditions described in the acoustic spectrum. In embodiments, the one or more tip-present conditions may include all known tip-present conditions in the acoustic spectrum. For example, based on the acoustic spectrum shown in Figure 22, 570 Hz may be selected because it exhibits a magnitude response of +5 dB in the tip-free condition and approximately -15 dB in both tip-present conditions (for the 350 μl tip and the 1000 μl tip). 570 Hz is merely an example, and other frequencies may be used as target frequencies in other embodiments. Different liquid dispenser systems may have different acoustic characteristics, necessitating the selection of different values ​​for the target frequency.

[0102] At operation 2304, a tip presence threshold is set using the system test response at the target frequency using the test signal in a tip-free condition. The tip presence threshold may be set as a percentage of the system test response voltage (corresponding to sound pressure) at the target frequency of the test signal in a tip-free condition. For example, the tip presence threshold may be set at 20% of the system test response voltage in a tip-free condition. In other examples, the tip presence threshold may be set at a value higher than 20%, e.g., 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc., or lower than 20%, e.g., 10%, 5%, etc. In further embodiments, the tip presence threshold may be set as a percentage of the acoustic power generated by the sound generator at the test signal target frequency in a tip-free condition.

[0103] In operation 2306, the liquid dispenser system provides a polling signal at the target frequency and test signal voltage and detects a system polling response voltage. The polling signal may be provided once in accordance with an operator command and / or system workflow. The polling signal may be provided continuously, e.g., the signal may be provided without interruption. The polling signal may be provided substantially continuously. The polling signal may also be provided at regular intervals, e.g., every second, every millisecond, every microsecond, etc.

[0104] At operation 2308, the presence of a tip may be determined and output. For example, if the system polling response voltage exceeds the tip present threshold, the controller 110 of the liquid dispenser system may determine that a tip is not present and the system is in a tip-free condition. If the system polling response voltage does not exceed the tip present threshold, a tip is determined to be present. If the polling response voltage is equal to the tip present threshold, the system can be configured for either determination.

[0105] The liquid dispenser system outputs a tip presence threshold value according to the tip presence threshold determination. The output may be provided in any suitable form, such as a notification on a display, a continuous tone or sound indicating a change of state, a light, etc. The output may be provided continuously, in response to a polling signal, and / or only in response to a change of state.

[0106] The embodiment discussed with respect to Figure 23 employs a target frequency at which the no-chip condition response exceeds the chip-present response, as shown in Figure 22. In further embodiments, a target frequency can be selected at which the chip-present condition response exceeds the no-chip condition response. Other operations of the method can be adjusted accordingly.

[0107] In further embodiments, automated pipetting system 100 can implement methods of tip identification, as described with respect to Figures 24-30. The tip identification methods can be performed using any suitable systems and hardware discussed herein, including any controller (e.g., controller 110), liquid dispensing system (e.g., liquid dispensing systems 100, 200, 298, 1200, 1700), liquid dispenser (e.g., liquid dispenser 130, 230, 330, 530, 580, 590, 630, 930, 1030, 1330), and any or all of their components. However, the tip identification methods described herein are not limited to the specific hardware and devices discussed herein and can be implemented by any suitable control system and liquid dispensing system. For example, the method of tip identification may be implemented by a liquid dispensing system described herein in conjunction with a controller, such as controller 110 depicted in FIG. 1B , which may employ any of its components (control circuitry 111, communication interface 113, non-transitory computer-readable medium 115 (e.g., memory or other computer-readable storage medium)) to implement the method of tip identification. In one embodiment, control circuitry 111 may include one or more processors, programmable logic circuits (PLCs) or programmable logic arrays (PLAs), field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), or any other control circuitry. In a further embodiment, as described with respect to FIG. 1B , for example, controller 110 may include analog-to-digital converter 117 that converts analog signals to digital signals, digital-to-analog converter 119 that converts digital signals to analog signals, and / or signal conditioning circuitry 121 that can manipulate various analog signals so that the analog signals can meet the requirements of their next stage for further processing.

[0108] In one embodiment, the control circuit 111 (FIG. 1B) may identify information about the dispensing tip (e.g., 247, or 347, 547, 647, etc. in FIG. 2A ) based on an average value of multiple squared voltage values, where the multiple squared voltage values ​​may be part of a pressure response associated with the acoustic sensor. Because the sound sensed by the acoustic sensor (e.g., 260, 360, etc.) may vary based on the structure of the dispensing tip, different types of dispensing tips may be identified based on the sound sensed by the acoustic sensor. For example, the average value of the squared voltage values ​​based on the sensed sound may be used to distinguish between different types of dispensing tips. In an embodiment, instead of the average value of multiple squared voltage values, the voltage response may be used directly for such tip identification.

[0109] Referring again to FIG. 22 , it can be seen that not only do dispensing tips generate acoustic spectra that are different from a no-tip condition, but different dispensing tips also generate acoustic spectra that are different from each other. Thus, a liquid dispenser system can be configured to determine the type of dispensing tip attached to the system according to its response to one or more test signals. For example, a 768 Hz test signal will produce significantly different responses from a 1000 μl dispensing tip versus a 350 μl dispensing tip. In some embodiments, the entire acoustic spectra of different dispensing tips can be compared to determine the identity of the dispensing tips. In further embodiments, a discrete number of selected target frequencies can be selected for comparison to determine the identity of the dispensing tips.

[0110] FIG. 24 is an exemplary diagram showing experimentally acquired acoustic spectra for multiple dispensing tip types. FIG. 24 shows the amplitude response, in dB, across a frequency range for four different tip types (10 μl, 50 μl, 350 μl, and 1,000 μl) and a no-tip condition. As shown in FIG. 24, the spectral patterns are somewhat similar, but the amplitude responses differ between the different tip conditions. Therefore, differences in amplitude responses at different frequencies can be used to identify a specific dispensing tip among several dispensing tip options. Systems consistent with embodiments herein, such as liquid dispenser systems, can compare the acoustic responses of the systems at one or more target frequencies to determine the type of dispensing tip.

[0111] In an embodiment, two acoustic spectra may be compared using the Pearson correlation coefficient (PCC). The PCC provides a measure of the linear correlation between two variables. The PCC may be used to represent the similarity between two data series over the entire length of the data series. An exact PCC represents a perfect linear correlation, and a PCC of zero represents no linear correlation.

[0112] 25A-28D are exemplary diagrams showing acoustic spectra experimentally acquired under different experimental conditions for multiple dispensing tip types.

[0113] 25A-25E are exemplary diagrams showing experimentally obtained acoustic spectra for several dispensing tip types with and without added noise. Instruments employing liquid dispensing tips may employ various fans, e.g., thermoelectric cooler (TEC) fans, ventilation fans, and other fans, which may generate noise. Figures 25A-25E show the amplitude response across a frequency range, measured in dB, for a no-tip condition (Figure 25A), a 1,000 μl dispensing tip (Figure 25B), a 350 μl dispensing tip (Figure 25C), a 50 μl dispensing tip (Figure 25D), and a 10 μl dispensing tip (Figure 25E) with and without a fan (WF (with fan)—fan condition) to add noise. Using PCC to determine the similarity of the data sets in Figures 25A-25E, it can be shown that the fanless data set for each tip correlates more closely with the fan-enabled data set for the same tip than with other data sets. These results are shown in Tables 1 and 2. Table 1 shows the PCC for each fanless condition compared to each of the other fanless conditions. Table 2 shows the PCC for each fanless condition compared to each fan-enabled condition. Therefore, determining the correlation between acoustic spectra can be used to reliably determine the identity of dispensing tips under conditions of varying noise. [Table 1] [Table 2]

[0114] Figures 26A-26E are exemplary diagrams showing experimentally acquired acoustic spectra at four different temperatures across multiple experiments for a 1,000 μl dispensing tip condition. Figures 26A-26D show the amplitude response in dB across a range of frequencies for the 1,000 μl dispensing tip condition at 20°C, 25°C, 30°C, and 35°C. Each of Figures 26A-26D shows the results of three frequency sweeps. Figure 26E shows the acoustic spectra for the four different temperatures on the same diagram. By using PCC to determine the similarity of the datasets in Figures 26A-26E, it can be shown that when the tip conditions are unchanged, the resulting acoustic spectra are highly correlated even at different temperatures. The datasets in Figures 26A-26D can also demonstrate a high correlation with the fanless and fan-on conditions of that experiment, as compared to the dataset in Figure 25B. Figures 27A-27E are exemplary diagrams showing experimentally acquired acoustic spectra at four different temperatures across multiple experiments for a 350 μl dispensing tip condition. Figures 27A-27D show the amplitude response in dB across a range of frequencies for the 350 μl dispensing tip conditions at 20°C, 25°C, 30°C, and 35°C. Each of Figures 27A-27D shows the results of three frequency sweeps. Figure 27E shows the acoustic spectra for the four different temperatures on the same diagram. By using PCC to determine the similarity of the datasets in Figures 27A-27E, it can be shown that when the tip conditions are unchanged, the resulting acoustic spectra are highly correlated even at different temperatures. The datasets in Figures 27A-27D can also demonstrate a high correlation with the fanless and fan-on conditions of that experiment, as compared to the dataset in Figure 25C.

[0115] 28A-28D are exemplary diagrams showing experimentally acquired acoustic spectra for a no-tip condition at four different temperatures across multiple experiments using three different levels of acoustic output from the sound generator. FIGS. 28A-28D show the amplitude response in dB across a range of frequencies for the no-tip condition at 20°C, 25°C, 30°C, and 35°C. Each of FIGS. 28A-28D shows the results of three frequency sweeps conducted at different speaker volumes. By using PCC to determine the similarity of the datasets in FIGS. 28A-28D, it can be shown that when the tip condition is unchanged, the resulting acoustic spectra are highly correlated even at different temperatures and different volumes. The datasets in FIGS. 28A-28D also demonstrate a high correlation with the no-fan and fan-on conditions of that experiment, compared to the dataset in FIG. 25A.

[0116] The data shown in Figures 26A-28D demonstrate that determining correlations between acoustic spectra can be used to reliably determine the identity of dispensing tips under conditions of varying temperature and varying volume. The data shown in Figures 26A-28E further demonstrate that the acoustic spectra associated with various liquid dispensing tips remain relatively stable across changes in temperature, volume, and ambient noise. The acoustic spectra recorded during these experiments demonstrate robustness given the varying conditions, demonstrating that comparison of acoustic spectra can reliably identify tip types in the face of potentially confounding experimental conditions. In embodiments, results using PCC can be improved by several techniques. For example, amplitudes can be converted from a linear to a logarithmic scale before determining the PCC between two data sets. In another example, preprocessing using a low-pass filter can be performed across the entire spectrum to improve data quality and eliminate excess noise. The cutoff frequency can be selected as a function of the Nyquist frequency, for example, 0.2 of the Nyquist frequency, or any other suitable value.

[0117] Figure 29 is an exemplary diagram showing experimentally acquired acoustic spectra for multiple dispensing tip types. Figure 29 shows amplitude gain in dB across a frequency range for four different tip types (10 μl, 50 μl, 350 μl, and 1,000 μl) and a no-tip condition. Figure 29 also shows multiple target frequencies that can be used for comparison to determine the identity of the dispensing tip.

[0118] In one embodiment, identifying a liquid dispensing tip from among multiple types of liquid dispensing tips may be performed based on three target frequency measurements for each liquid dispensing tip, rather than using the entire acoustic spectrum. In one embodiment, the three target frequency measurements may be selected according to the resonant peak locations of the acoustic spectra associated with different liquid dispensing tips. For example, the 1,000 μl dispensing tip is the only dispensing tip with a resonant peak between frequencies F1 and F3 in FIG. 29. Therefore, Mag(F2) - Mag(F1) is positive, and Mag(F3) - Mag(F2) is negative. This pattern applies only to the 1,000 μl dispensing tip. As shown in FIG. 29, the peak for the 350 μl liquid dispensing tip is near F4 or between F3 and F5, the peak for the 50 μl liquid dispensing tip is near F7 or between F6 and F8, and the peak for the 10 μl liquid dispensing tip is near F9 or between F8 and F10. Thus, each of the four liquid dispensing tips can be uniquely identified by a simple comparison involving the addition or subtraction of the system response at three distinct frequencies. As shown in FIG. 29, the target frequencies can be selected according to a predetermined interval between each target frequency. In a further embodiment, the target frequencies can be selected according to an analysis of the acoustic spectrum such that a resonant peak of the acoustic spectrum falls between two target frequencies, and a third target frequency also falls between two target frequencies. Depending on the number of dispensing tips that need to be distinguished and the locations of the resonant peaks, fewer or more target frequencies may be used.

[0119] 30 shows a flow diagram of a method of tip identification (identification) consistent with embodiments herein. Method 3000 can be employed in any of the liquid dispenser systems and devices discussed herein. The operations and / or steps of method 3000 can be performed by any suitable control system discussed herein (e.g., controller 110 of FIG. 1B). In embodiments, structural improvements to the dispense chamber cavity discussed herein can be applied to liquid dispenser systems and devices employed in method 3000 of tip identification.

[0120] Method 3000 is discussed below with respect to signals having a frequency and a voltage. As discussed herein, a signal, such as a test or polling signal disclosed below, in a liquid dispenser system is provided to a sound generator of the liquid dispenser system, which then generates an acoustic output having a frequency corresponding to the frequency of the test or polling signal and having a magnitude corresponding to the voltage of the test or polling signal. An acoustic sensor detects an acoustic or other system response to the acoustic output, and a response signal having a frequency and voltage corresponding to the frequency and magnitude of the acoustic response is provided to a control circuit (e.g., 111) of the liquid dispenser system.

[0121] At operation 3002, method 3000 includes verifying the presence of a dispensing tip. The presence of a dispensing tip may be ensured, for example, via tip presence detection method 2300 discussed above with respect to Figure 23. In further embodiments, tip presence detection may be performed by any suitable means, such as electrical detection, mechanical detection, optical detection, manual detection by an operator, etc.

[0122] At operation 3004, the method 3000 includes providing polling signals at a plurality of target frequencies. In one embodiment, the plurality of target frequencies may include a plurality of individual target frequencies. In one embodiment, the plurality of target frequencies may also include a complete frequency sweep over a particular frequency range in particular frequency increments.

[0123] At operation 3006, the method 3000 includes determining a tip identification. The tip identification is determined according to a comparison of the system response at the multiple target frequencies to one or more tip identification metrics, and determining the identity of the liquid dispensing tip according to the comparison. Comparing the system response at the multiple target frequencies to one or more tip identification metrics can be performed in several ways.

[0124] In one embodiment, the tip identification metric may be a threshold PCC between the system response and one or more stored acoustic spectra. The multiple target frequencies may include a frequency sweep across a frequency range. Polling signals provided at the multiple target frequencies generate a tip response acoustic spectrum. The tip response acoustic spectrum may be compared to one or more tip identification acoustic spectra stored and accessible by the control circuitry (e.g., 111) of the liquid dispenser system. The tip identification acoustic spectrum may be stored, for example, in a look-up table.

[0125] The tip identification acoustic spectrum may be predetermined and stored in one or more storage media associated with or accessible by the control circuitry of the liquid dispenser system. The tip identification acoustic spectrum may be established under standard conditions, such as an ambient temperature of 25°C, environmental noise generated by or mimicking the liquid dispenser system, a standard sound generator volume loud enough to overcome the environmental noise but not saturate the acoustic sensor, and a frequency range of approximately 200 Hz to 3 kHz, 500 Hz to 2500 kHz, and / or any suitable range. The tip identification acoustic spectrum thus generated may be further filtered, for example, via a low-pass filter, to remove artifacts or noise in the signal. The tip identification acoustic spectrum may be previously established by another device and imported into the liquid dispenser system. The tip identification spectrum may be established by the liquid dispenser system during an initial setup or calibration operation. The tip identification spectrum may further be re-established at intervals to keep the calibration updated.

[0126] The comparison between the tip response acoustic spectrum and the stored tip identification acoustic spectrum may include calculating a PCC and / or any other suitable method of comparing these data sets. The maximum PCC value that exceeds a PCC threshold may be used to determine the identity of the dispensing tip used to generate the tip response acoustic spectrum. For example, an operator may attach a 350 μl tip to a liquid dispenser system. The liquid dispenser system's control circuitry (e.g., 111) then acquires the tip response acoustic spectrum of the attached tip and generates a PCC between the tip response acoustic spectrum and one or more stored tip identification acoustic spectra. As discussed above, the PCC between the tip response acoustic spectrum of the 350 μl dispense tip in this example and the stored tip identification acoustic spectrum for the 350 μl dispense tip has the maximum value, indicating that the attached tip is closest to the 350 μl dispense tip. The system may further perform a threshold check to determine that the 350 μl dispense tip response acoustic spectrum also matches stored 350 μl dispense tip data that exceeds a predetermined level, such as a PCC threshold. For example, the PCC threshold may be 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, and / or 0.95. The PCC threshold requirement may verify that a detected tip is actually a 350 μl dispensing tip and not an unknown dispensing tip that is closest to the 350 μl dispensing tip. In embodiments, the liquid dispenser system may be configured to provide an alert or warning indicating that an unknown tip has been installed when a dispensing tip that does not exceed the PCC threshold is installed.

[0127] In another embodiment, the tip identification metric may include a requirement that the system response at three target frequencies for the liquid dispensing tip being identified match a stored tip response pattern. As discussed above, e.g., with respect to FIG. 29, the multiple target frequencies may include a range of target frequencies selected to identify the dispensing tip based on predicted response amplitude peaks. The system response at the selected three target frequencies can identify the location of peaks in the tip response acoustic spectrum without polling the entire spectrum. For example, with reference to FIG. 29, for a 1000 μl dispensing tip, the tip identification metric may determine whether the system response at F1, F2, and F3 matches a stored tip response pattern in which magnitude (F2) minus magnitude (F1) is positive and magnitude (F3) minus magnitude (F2) is negative. Each known dispensing tip may have a tip response pattern stored as a tip identification metric. The system response at the multiple target frequencies can be compared to each tip response pattern to determine the identity of the attached dispensing tip. In situations where the multiple target frequencies do not match any stored tip response patterns, the liquid dispenser system may be configured to alert or warn that an unknown dispensing tip has been attached.

[0128] At operation 3008, the method 3000 includes outputting the determined liquid dispensing tip type. As discussed above, the identity of the liquid dispensing tip type is determined according to a comparison between the plurality of target frequencies and the tip identification metric. The liquid dispenser system is configured to output the identity of the liquid dispensing tip type in any suitable manner, such as, for example, by a tone or sound, by a series of lights, on a display, etc.

[0129] Method 3000 for determining a liquid dispensing tip type can be combined with method 2300 for determining the presence of a liquid dispensing tip. For example, the liquid dispenser system may be configured to continuously monitor for the presence of a tip and update a display or other notification upon detection of a liquid dispensing tip. After determining the presence of a tip, the liquid dispenser system may be configured to operate in a liquid dispensing tip identification mode and provide continuous updates to a display or other notification indicating the identity of the attached liquid dispensing tip.

[0130] In embodiments, the tip identification metric may be further configured to include a no-tip condition for tip identity. Thus, in liquid dispensing tip identification method 3000, determining the identity of the liquid dispensing tip may include determining that no tip is present. In such embodiments, tip presence verification operation 3002 may not be required.

[0131] In embodiments, tip presence detection method 2300 and tip identification method 3000 may be implemented in a liquid dispenser system that includes multiple liquid dispensing devices or modules, each with its own liquid dispensing tip. In embodiments, tip presence detection method 2300 and liquid dispensing tip identification method 3000 may be implemented simultaneously in multiple liquid dispensing modules. Contrary to what might be expected, experiments described herein demonstrate that crosstalk between multiple liquid portion dispensing modules does not interfere with presence and identification results.

[0132] Table 3 shows voltage response results from seven liquid dispensing device modules spaced 10 mm apart that were simultaneously polled with a 560 Hz tip presence detection polling signal. Six data points were acquired for each of the seven dispensing modules. Table 4 shows voltage response results from the first two of the seven liquid dispensing module tip presence detection polling signals that were simultaneously conducted (at 560 Hz). Six data points were acquired for each of the two modules. As shown by comparing the results in Tables 3 and 4, the voltage responses of modules #1 and #2 are substantially similar regardless of whether or not the tip presence detection polling signals of modules #3 through #7 are activated. Therefore, the tip presence detection method and tip identification method can be implemented simultaneously on multiple liquid dispensing modules of a liquid dispenser system. Such simultaneous implementation can reduce the time required to update tip presence and tip identification notifications because each module does not need to be tested separately. [Table 3] [Table 4]

[0133] FIG. 31 is an example block diagram 3500 showing a block diagram for processing the voltage output from the acoustic sensor. The functions implemented in block diagram 3500 may be performed by controller 110. At 3510, the voltage output from the acoustic sensor is received by controller 110 and passed through a low-pass filter (e.g., a low-pass filter in signal conditioning circuit 121). The low-pass filter may reduce noise in the voltage output and / or limit the bandwidth of the voltage output to reduce anti-aliasing effects and / or improve the signal-to-noise ratio. Then, at 3520, the output from the low-pass filter is passed through an analog-to-digital converter (e.g., analog-to-digital converter 117) to convert the output from an analog voltage value to a digital voltage value. At 3530, the voltage values ​​are each squared (e.g., by control circuit 111) to generate a squared voltage value. As discussed above, the squared voltage value is linearly proportional to the acoustic power or intensity. An average value of the squared voltage values ​​over a set time window can be determined (e.g., by control circuitry 111), and the average value of the squared voltage values ​​is related to the average power or average intensity within the set time window. Thus, as discussed above, the average value of the squared voltage values ​​can be monitored to determine whether tip-liquid contact has occurred and / or whether the tip has been coupled to a liquid dispenser.

[0134] FIG. 32 is an exemplary diagram illustrating the elimination of false positive errors when tip-liquid contact is detected based on a value associated with the average power or intensity of sound. The diagram in FIG. 32 graphically illustrates experimental results of values ​​associated with the average power or intensity of sound over time. The dash-dotted line on the graph indicates the threshold for determining whether tip-liquid contact occurred. In this experiment, actual tip-liquid contact occurred at 2000 milliseconds. In the embodiment shown in FIG. 32, no false positive errors are detected even in the presence of various types of background noise, such as white noise (solid gray line), 400 Hz single-tone noise (dotted line), and strong wind noise (solid black line).

[0135] Further embodiments include: Embodiment 1 is a liquid dispenser comprising: a dispenser body including a dispenser chamber portion including a dispensing chamber therein, the dispensing chamber having a first opening at a first portion of the dispenser chamber portion and a second opening at a second portion of the dispenser chamber portion, the first portion configured to mate with a dispensing tip; and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispenser chamber via the second opening and configured to guide a piston in a linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispenser chamber; and an acoustic sensor configured to sense sound within the dispenser chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispenser chamber portion.

[0136] Embodiment 2 is a liquid dispenser according to embodiment 1, further comprising a control circuit configured to determine whether contact between the dispensing tip and the liquid has occurred based on the detected sound.

[0137] Embodiment 3 is the liquid dispenser of embodiment 1 or 2, wherein the sound generator and the acoustic sensor are positioned facing each other or on the same side.

[0138] Embodiment 4 is the liquid dispenser according to any one of embodiments 1 to 3, wherein the dispensing chamber is enclosed except for the first opening and the second opening.

[0139] Embodiment 5 is the liquid dispenser of embodiment 2 or 3, wherein the control circuit is further configured to identify information about the dispensing tip based on the sensed sound.

[0140] Embodiment 6 is a liquid dispenser described in embodiment 5, wherein the sensed sound includes a sound pressure sensed within the dispensing chamber, and information about the dispensing tip is identified based on the sensed sound pressure.

[0141] Embodiment 7 is a liquid dispenser described in any one of embodiments 1 to 3, wherein the control circuit is further configured to determine whether the dispensing tip is fully engaged with the first portion of the dispensing chamber portion based on the detected sound.

[0142] Embodiment 8 is a liquid dispenser system, the liquid dispenser system comprising a liquid dispenser body, a dispenser chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber via the second opening, and guiding a piston in a linear motion within the piston chamber to dispense a liquid. a piston chamber portion configured to draw liquid into the dispenser and dispense liquid out of the dispenser; a liquid dispenser including a sound generator configured to generate sound to induce acoustic resonance in the dispense chamber; and an acoustic sensor configured to sense sound in the dispense chamber, wherein at least one of the sound generator or the acoustic sensor is disposed in the dispense chamber portion; and a control circuit configured to determine whether contact between the dispensing tip and the liquid has occurred based on the sensed sound.

[0143] Embodiment 9 is a liquid dispenser system described in embodiment 8, further comprising a liquid dispenser transport device configured to move the liquid dispenser and a piston drive device configured to move the piston within the piston chamber.

[0144] Embodiment 10 is the liquid dispenser system of embodiment 8 or 9, wherein the sound generator and the acoustic sensor are positioned facing each other or positioned on the same side.

[0145] Embodiment 11 is a liquid dispenser system according to any one of embodiments 8 to 10, wherein the dispensing chamber is enclosed except for the first opening and the second opening.

[0146] Embodiment 12 is a liquid dispenser system described in any one of embodiments 8 to 11, wherein the control circuit is further configured to identify information about the dispensing tip based on the detected sound.

[0147] Embodiment 13 is a liquid dispenser system described in any one of embodiments 8 to 12, wherein the sensed sound includes a sound pressure sensed within the dispensing chamber, and information about the dispensing tip is identified based on the sensed sound pressure.

[0148] Embodiment 14 is a liquid dispenser system described in any one of embodiments 8 to 13, wherein the control circuit is further configured to determine whether the dispensing tip is fully engaged with the first portion of the dispensing chamber portion based on the detected sound.

[0149] Embodiment 15 is a liquid dispenser comprising a dispenser body, a dispenser chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector channel connecting the respective cavity to the dispense chamber, and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber via the second opening, and a piston chamber portion including a piston chamber. a piston chamber portion configured to direct a piston in a linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispensing chamber; and an acoustic sensor configured to sense sound within the dispensing chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within a respective cavity of one of the one or more side conduits, and wherein the respective cavity and respective connector of each of the one or more side conduits is free of resonance within a frequency range of sound sensed by the acoustic sensor.

[0150] Embodiment 16 is a liquid dispenser described in embodiment 15, further comprising a control circuit configured to determine whether contact between the dispensing tip and the liquid has occurred based on the detected sound.

[0151] Embodiment 17 is a liquid dispenser according to embodiment 15 or 16, wherein the respective cavity and the respective connector of each of the one or more side conduits is free of Helmholtz resonance.

[0152] An eighteenth embodiment is a liquid dispenser according to any one of the fifteenth to seventeenth embodiments, wherein the lateral dimension of each cavity is the same as the lateral dimension of a respective connector for each of the one or more side conduits.

[0153] Embodiment 19 is the liquid dispenser of any one of embodiments 15 to 18, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 100 Hz to 4 kHz.

[0154] Embodiment 20 is the liquid dispenser of any one of embodiments 15 to 19, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 200 Hz to 1 kHz.

[0155] Embodiment 21 is a liquid dispenser described in any one of embodiments 15 to 20, wherein each of the one or more side conduits has a respective cavity configured to accommodate at least one of a sound generator or an acoustic sensor.

[0156] Embodiment 22 is a liquid dispenser described in any one of embodiments 15 to 21, wherein the one or more side conduits include a single side conduit, and one of the sound generator and the acoustic sensor is housed within the single side conduit, and the other of the sound generator and the acoustic sensor is housed in the dispensing chamber portion.

[0157] Embodiment 23 is a liquid dispenser system comprising: a dispenser body including a dispenser chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber via the second opening and configured to guide a piston in a linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispense chamber; and an acoustic sensor configured to sense sound within the dispense chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion.

[0158] Embodiment 24 is a liquid dispenser system described in embodiment 23, further comprising a liquid dispenser transport device configured to move the liquid dispenser and a piston drive device configured to move the piston within the piston chamber.

[0159] Embodiment 25 is a liquid dispenser system described in embodiment 23 or 24, further comprising a control circuit configured to determine whether contact between the dispensing tip and the liquid has occurred based on the detected sound.

[0160] Embodiment 26 is a liquid dispenser system described in any one of embodiments 23 to 25, wherein the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispensing chamber, and wherein the respective cavity and respective connector of each of the one or more side conduits are free of Helmholtz resonance.

[0161] Embodiment 27 is a liquid dispenser system according to any one of embodiments 23 to 26, wherein the lateral dimensions of each cavity are the same as the lateral dimensions of each connector for each of the one or more side conduits.

[0162] Embodiment 28 is a liquid dispenser system according to any one of embodiments 23 to 27, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 100 Hz to 4 kHz.

[0163] Embodiment 29 is a liquid dispenser system according to any one of embodiments 23 to 28, wherein the acoustic resonance in one or more side conduits is outside the frequency range of 200 Hz to 1 kHz.

[0164] Embodiment 30 is a liquid dispenser system described in any one of embodiments 23 to 29, wherein the cavity of each of the one or more side conduits is configured to accommodate at least one of a sound generator or an acoustic sensor.

[0165] Embodiment 31 is a liquid dispenser system described in any one of embodiments 23 to 30, wherein the one or more side conduits include a single side conduit, and one of the sound generator and the acoustic sensor is housed within the single side conduit, and the other of the sound generator and the acoustic sensor is housed in the dispensing chamber portion.

[0166] Embodiment 32 is a liquid dispenser comprising: a dispenser body including a dispenser chamber portion including a dispenser chamber therein, the dispenser chamber having a first opening at a first portion of the dispenser chamber portion and a second opening at a second portion of the dispenser chamber portion, the first portion configured to mate with a dispensing tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispenser chamber via the second opening and configured to direct a piston in a linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; and an acoustic filter disposed between the dispense chamber and the piston chamber, the acoustic filter configured to acoustically isolate the dispense chamber from the piston chamber; a sound generator configured to generate sound in the dispense chamber; and an acoustic sensor configured to sense an acoustic signal resulting from the generated sound.

[0167] Embodiment 33 is a liquid dispenser described in embodiment 32, further comprising a control circuit configured to determine at least one of whether contact between the dispensing tip and the liquid has occurred based on the detected sound, or the volume of liquid in the dispensing tip based on the detected sound.

[0168] Embodiment 34 is a liquid dispenser according to embodiment 32 or 33, wherein the length of the air column resonance in the dispensing chamber is not affected by the movement of the piston.

[0169] Embodiment 35 is a liquid dispenser according to any one of embodiments 32 to 34, wherein the acoustic filter includes at least one of a sound-reflecting filter or a sound-absorbing filter.

[0170] Embodiment 36 is a liquid dispenser described in any one of embodiments 32 to 35, wherein the sound-reflecting filter is configured to isolate the length of the air column resonance in the dispensing chamber from the length of the air column resonance in the piston chamber.

[0171] Embodiment 37 is the liquid dispenser according to any one of embodiments 32 to 36, wherein the sound reflecting filter is air impermeable.

[0172] Embodiment 38 is a liquid dispenser according to any one of embodiments 32 to 37, wherein the sound absorbing filter is configured to reduce sound caused by movement of the piston.

[0173] Embodiment 39 is the liquid dispenser of any one of embodiments 32-38, wherein the sound absorbing filter is air permeable and sound dampening.

[0174] Embodiment 40 is a liquid dispenser described in any one of embodiments 32 to 39, wherein the acoustic filter is made of at least one of open-cell foam, closed-cell foam with air passages, or fibrous material.

[0175] Embodiment 41 is a liquid dispenser according to any one of embodiments 32 to 40, wherein at least one of a sound generator or an acoustic sensor is disposed within the dispensing chamber portion.

[0176] Embodiment 42 is a liquid dispenser described in any one of embodiments 32 to 41, wherein the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispensing chamber, at least one of a sound generator or an acoustic sensor disposed within the one or more side conduits, and wherein the respective cavity and respective connector of each of the one or more side conduits does not resonate within the frequency range of sound sensed by the acoustic sensor.

[0177] Embodiment 43 is a liquid dispenser described in any one of embodiments 32 to 42, wherein the control circuit is further configured to identify information about the dispensing tip based on the detected sound.

[0178] Embodiment 44 is a liquid dispenser described in any one of embodiments 32 to 43, wherein the control circuit is further configured to determine whether the dispensing tip is fully engaged with the first portion of the dispensing chamber portion based on the detected sound.

[0179] Embodiment 45 is a liquid dispenser system, the liquid dispenser system comprising a liquid dispenser body, a dispenser chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip, and a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispense chamber through the second opening, for guiding a piston in a linear motion within the piston chamber to draw liquid into the liquid dispenser and dispense liquid out of the liquid dispenser. a piston chamber portion configured to acoustically isolate the dispensing chamber from the piston chamber; a sound generator configured to generate sound in the dispensing chamber; and an acoustic sensor configured to sense an acoustic signal resulting from the generated sound; and a control circuit configured to determine at least one of whether contact between the dispensing tip and the liquid has occurred or the volume of liquid in the dispensing tip based on the sensed sound.

[0180] Embodiment 46 is a liquid dispenser system described in embodiment 45, further comprising a liquid dispenser transport device configured to move the liquid dispenser and a piston drive device configured to move the piston within the piston chamber.

[0181] Embodiment 47 is a liquid dispenser system according to embodiment 45 or 46, wherein the length of the air column resonance in the dispense chamber is not affected by the movement of the piston.

[0182] Embodiment 48 is a liquid dispenser system according to embodiment 45 or 46, wherein the acoustic filter comprises at least one of a sound-reflecting filter or a sound-absorbing filter.

[0183] Embodiment 49 is a liquid dispenser system described in any one of embodiments 45 to 48, wherein the sound-reflecting filter is configured to isolate the length of the air column resonance in the dispensing chamber from the length of the air column resonance in the piston chamber.

[0184] Embodiment 50 is a liquid dispenser system according to any one of embodiments 45 to 49, wherein the sound-reflecting filter is impermeable to air.

[0185] Embodiment 51 is a liquid dispenser system according to any one of embodiments 45 to 50, wherein the sound absorbing filter is configured to reduce sound caused by movement of the piston.

[0186] Embodiment 52 is a liquid dispenser system according to any one of embodiments 45 to 51, wherein the sound absorbing filter is air permeable and sound dampening.

[0187] Embodiment 53 is a liquid dispenser system described in any one of embodiments 45 to 52, wherein the acoustic filter is made of at least one of open-cell foam, closed-cell foam with air passages, or fibrous material.

[0188] Embodiment 54 is a liquid dispenser system according to any one of embodiments 45 to 53, wherein at least one of the sound generator or acoustic sensor is disposed within the dispense chamber portion.

[0189] Embodiment 55 is a liquid dispenser system described in any one of embodiments 45 to 54, wherein the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispensing chamber, at least one of a sound generator or an acoustic sensor is disposed within the one or more side conduits, and the respective cavity and respective connector of each of the one or more side conduits does not resonate within the frequency range of the sound sensed by the acoustic sensor.

[0190] Embodiment 56 is a liquid dispenser system described in embodiment 45 or 46, wherein the control circuit is further configured to identify information about the dispensing tip based on the sensed sound.

[0191] Embodiment 57 is a liquid dispenser system described in any one of embodiments 45 to 56, wherein the control circuit is further configured to determine whether the dispensing tip is fully engaged with the first portion of the dispensing chamber portion based on the detected sound.

[0192] Embodiment 58 is a method for detecting contact between a liquid dispenser and a liquid, the method including: obtaining, via an acoustic sensor, a plurality of voltage values ​​associated with sound sensed by the acoustic sensor within a time window; squaring each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculating an average value of the plurality of squared voltage values ​​for the time window; and determining whether contact between a dispensing tip of the liquid dispenser and the liquid has occurred during the time window based on the average value of the plurality of squared voltage values.

[0193] Embodiment 59 is a method according to embodiment 58, in which determining whether contact with a liquid has occurred includes determining that contact with a liquid has occurred when the average value of the plurality of squared voltage values ​​is less than a threshold value, and determining that contact with a liquid has not occurred when the average value of the plurality of squared voltage values ​​is greater than or equal to a threshold value.

[0194] Embodiment 60 is the method of embodiment 58 or 59, in which multiple voltage values ​​are obtained over the time domain.

[0195] Embodiment 61 is the method according to any one of embodiments 58 to 60, wherein the plurality of voltage values ​​are obtained across a frequency domain.

[0196] Embodiment 62 is the method according to any one of embodiments 58 to 61, wherein the plurality of voltage values ​​is obtained over a predetermined frequency band including a plurality of frequencies.

[0197] Embodiment 63 is the method according to any one of embodiments 58 to 62, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

[0198] Embodiment 64 is the method of any one of embodiments 58 to 63, wherein the sound sensed by the acoustic sensor is sensed from sound traveling within the liquid dispenser.

[0199] Embodiment 65 is a method according to any one of embodiments 58 to 64, wherein at least one of the acoustic sensor or the sound generator that is the source of the sensed sound is located within the interior of the liquid dispenser.

[0200] Embodiment 66 is a controller for detecting contact between a liquid dispenser and a liquid, comprising: a memory; and a control circuit coupled to the memory and an acoustic sensor included in the liquid dispenser, the control circuit configured to sense sound and generate a plurality of voltage values ​​based on the sound sensed within a time window, the control circuit configured to: acquire the plurality of voltage values ​​via the acoustic sensor; square the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculate an average value of the plurality of squared voltage values ​​for the time window; and determine whether contact between the liquid dispenser and the liquid occurred during the time window based on the average value of the plurality of squared voltage values.

[0201] Embodiment 67 is a controller described in embodiment 66, in which the control circuit determines whether contact with the liquid has occurred by determining that contact with the liquid has occurred when the average value of the multiple squared voltage values ​​is less than a threshold value, and determining that contact with the liquid has not occurred when the average value of the multiple squared voltage values ​​is greater than or equal to a threshold value.

[0202] Embodiment 68 is the controller of embodiment 66 or 67, wherein multiple voltage values ​​are obtained over the time domain.

[0203] Embodiment 69 is the controller according to any one of embodiments 66 to 68, wherein the plurality of voltage values ​​are obtained across a frequency domain.

[0204] Embodiment 70 is the controller according to any one of embodiments 66 to 69, wherein the plurality of voltage values ​​is obtained over a predetermined frequency band including a plurality of frequencies.

[0205] Embodiment 71 is the controller according to any one of embodiments 66 to 70, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

[0206] Embodiment 72 is the controller of any one of embodiments 66 to 70, wherein the sound sensed by the acoustic sensor is sensed from sound traveling within the liquid dispenser.

[0207] Embodiment 73 is a liquid dispenser system for detecting a gas-liquid boundary, comprising: a liquid dispenser including a sound generator configured to generate sound inside the liquid dispenser and an acoustic sensor configured to sense an acoustic signal resulting from the generated sound; and a control circuit coupled to the acoustic sensor and configured to: acquire, via the acoustic sensor, a plurality of voltage values ​​associated with the sound sensed by the acoustic sensor within a time window; square each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculate an average value of the plurality of squared voltage values ​​for the time window; and determine whether contact between a dispensing tip of the liquid dispenser and a liquid occurred during the time window based on the average value of the plurality of squared voltage values.

[0208] Embodiment 74 is a liquid dispenser system as described in embodiment 73, in which the control circuit determines whether contact with the liquid has occurred by determining that contact with the liquid has occurred when the average value of the multiple squared voltage values ​​is less than a threshold value, and determining that contact with the liquid has not occurred when the average value of the multiple squared voltage values ​​is greater than or equal to a threshold value.

[0209] Embodiment 75 is a liquid dispenser system described in embodiment 73 or 74, wherein multiple voltage values ​​are acquired over the time domain.

[0210] Embodiment 76 is the liquid dispenser system of any one of embodiments 73-75, wherein the multiple voltage values ​​are obtained across a frequency domain.

[0211] Embodiment 77 is the liquid dispenser system of any one of embodiments 73-76, wherein the multiple voltage values ​​are obtained across a predetermined frequency band comprising multiple frequencies.

[0212] Embodiment 78 is a liquid dispenser system according to any one of embodiments 73 to 77, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

[0213] Embodiment 79 is a liquid dispenser system according to any one of embodiments 73 to 78, wherein the sound sensed by the acoustic sensor is sensed from sound traveling within the liquid dispenser.

[0214] Embodiment 80 is a liquid dispenser system comprising a control circuit configured to provide at least one test signal; and a liquid dispenser, the liquid dispenser including a dispenser body including a dispense chamber therein, a sound generator configured to generate at least one test sound in response to at least one test signal from the control circuit, and an acoustic sensor configured to sense the at least one sound in the dispense chamber and provide at least one response signal to the control circuit, wherein the control circuit is configured to compare the at least one response signal with a tip presence threshold signal value to determine the presence of a liquid dispensing tip.

[0215] Embodiment 81 is a liquid dispenser system as described in embodiment 80, wherein the control circuit is further configured to generate at least one test signal at a target frequency in a chip-free condition, and to determine a chip-present threshold signal value based on at least one response signal received during the chip-free condition.

[0216] Embodiment 82 is a liquid dispenser system described in embodiment 80 or 81, wherein the control circuit is further configured to output a notification of the presence of a liquid dispensing tip.

[0217] Embodiment 83 is a method for identifying the presence of a liquid dispensing tip, performed in a liquid dispenser system, comprising: providing at least one test signal by a control circuit; receiving the at least one test signal by a liquid dispenser including a dispenser body having a dispensing chamber, a sound generator, and an acoustic sensor; generating at least one test sound by the sound generator in response to the at least one test signal from the control circuit; sensing at least one sound in the dispensing chamber by the acoustic sensor; providing at least one response signal based on the at least one sound to the control circuit by the acoustic sensor; and comparing the at least one response signal with a tip presence threshold signal value to determine the presence of a liquid dispensing tip.

[0218] Embodiment 84 is a method according to embodiment 83, further configured to generate at least one test signal at the target frequency in a chip-free condition, and determine a chip presence threshold signal value based on a response signal received during the chip-free condition.

[0219] Embodiment 85 is a method according to embodiment 83 or 84, further comprising outputting a notification of the presence of a liquid dispensing tip.

[0220] Embodiment 86 is a liquid dispenser system comprising: a control circuit configured to provide at least one test signal; and a liquid dispenser, the liquid dispenser including a dispenser body including a dispense chamber therein; a sound generator configured to generate at least one test sound in response to the at least one test signal from the control circuit; and an acoustic sensor configured to sense the at least one sound in the dispense chamber and provide at least one response signal to the control circuit, wherein the control circuit is configured to compare the at least one response signal with a tip identification metric to determine the identity of the liquid dispenser tip.

[0221] Embodiment 87 is a liquid dispenser system described in embodiment 86, wherein the control circuit is further configured to verify the presence of a liquid dispensing tip.

[0222] Embodiment 88 is a liquid dispenser system described in embodiment 86 or 87, wherein the control circuit is further configured to output notification of the identity of the liquid dispensing tip.

[0223] Embodiment 89 is a liquid dispenser system described in any one of embodiments 86 to 88, wherein at least one test signal includes a frequency sweep, at least one response signal includes a tip response acoustic spectrum, and the control circuit is further configured to compare at least one response signal with a tip identification metric by determining a Pearson correlation coefficient between the tip response acoustic spectrum and one or more stored tip identification acoustic spectra.

[0224] Embodiment 90 is a liquid dispenser system described in any one of embodiments 86 to 89, wherein at least one test signal includes a frequency sweep, at least one response signal includes a response acoustic spectrum, and the control circuit is further configured to compare the response signal with a tip identification metric by matching the at least one response signal to a tip frequency response pattern.

[0225] Embodiment 91 is a method for determining the identity of a liquid dispensing tip in a liquid dispenser system, the method including: providing at least one test signal via a control circuit; receiving the at least one test signal by a liquid dispenser including a dispenser body having a dispensing chamber, a sound generator, and an acoustic sensor; generating at least one test sound by the sound generator in response to the at least one test signal from the control circuit; sensing at least one sound in the dispense chamber by the acoustic sensor; providing at least one response signal by the acoustic sensor based on the at least one sound; and comparing the at least one response signal with a tip identification metric to determine the identity of the liquid dispensing tip.

[0226] Embodiment 92 is the method of embodiment 91, further comprising verifying the presence of a liquid dispensing tip.

[0227] Embodiment 93 is a method according to embodiment 91 or 92, further comprising outputting a notification of the identity of the liquid dispensing tip.

[0228] Embodiment 94 is a method described in any one of embodiments 91 to 93, wherein at least one test signal includes a frequency sweep and at least one response signal includes a chip response acoustic spectrum, and the method further includes comparing at least one response signal with a chip identification metric by determining a Pearson correlation coefficient between the chip response acoustic spectrum and one or more stored chip identification acoustic spectra.

[0229] Embodiment 95 is a method described in any one of embodiments 91 to 94, wherein at least one test signal includes a frequency sweep and at least one response signal includes a response acoustic spectrum, and the method further includes comparing at least one response signal with a chip identification metric by matching the at least one response signal to a chip frequency response pattern.

[0230] While various embodiments according to the present invention have been described above, it should be understood that these embodiments are presented by way of illustration and example only, and not by way of limitation. It will be apparent to those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Accordingly, the breadth and scope of the present invention should not be limited by any of the exemplary embodiments described above, but should be defined only in accordance with the appended claims and their equivalents. It will also be understood that each feature of each embodiment discussed herein and each reference cited herein can be used in combination with the features of any other embodiment. All patents and publications discussed herein are incorporated herein by reference in their entirety.

Claims

1. A liquid dispenser, comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispensing chamber; an acoustic sensor configured to sense sound within the dispense chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion.

2. 10. The liquid dispenser of claim 1, further comprising a control circuit configured to determine if contact between the dispensing tip and liquid has occurred based on the sensed sound.

3. The liquid dispenser of claim 1 or 2, wherein the sound generator and the acoustic sensor are positioned facing each other or on the same side.

4. The liquid dispenser according to any one of claims 1 to 3, wherein the dispensing chamber is enclosed except for the first opening and the second opening.

5. The control circuit The liquid dispenser of claim 2 , further configured to identify information about the dispensing tip based on the sensed sound.

6. 6. The liquid dispenser of claim 5, wherein the sensed sound comprises a sound pressure sensed within the dispensing chamber, and the information regarding the dispensing tip is identified based on the sensed sound pressure.

7. The control circuit 7. The liquid dispenser of claim 2, further configured to determine whether the dispensing tip is fully coupled to the first portion of the dispensing chamber portion based on the detected sound.

8. 1. A liquid dispenser system, comprising: A liquid dispenser comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispensing chamber; a liquid dispenser including: an acoustic sensor configured to sense sound within the dispense chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion; and a control circuit configured to determine whether contact between the dispensing tip and a liquid has occurred based on the sensed sound.

9. a liquid dispenser transport device configured to move the liquid dispenser; 9. The liquid dispenser system of claim 8, further comprising: a piston driver configured to drive the piston within the piston chamber.

10. 10. The liquid dispenser system of claim 8 or 9, wherein the sound generator and the acoustic sensor are positioned facing each other or on the same side.

11. The liquid dispenser system of any one of claims 8 to 10, wherein the dispensing chamber is enclosed except for the first opening and the second opening.

12. The control circuit The liquid dispenser system of any one of claims 8 to 11, further configured to identify information about the dispensing tip based on the sensed sound.

13. 13. The liquid dispenser system of claim 12, wherein the sensed sound comprises a sound pressure sensed within the dispense chamber, and the information regarding the dispense tip is identified based on the sensed sound pressure.

14. The control circuit 14. The liquid dispenser system of claim 8, further configured to determine whether the dispensing tip is fully coupled with the first portion of the dispensing chamber portion based on the sensed sound.

15. A liquid dispenser, comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector channel connecting the respective cavity to the dispense chamber; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispensing chamber; an acoustic sensor configured to sense sound within the dispensing chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the respective cavity of one of the one or more side conduits, and wherein the respective cavity and the respective connector of each of the one or more side conduits is free of resonance within a frequency range of the sound sensed by the acoustic sensor.

16. 16. The liquid dispenser of claim 15, further comprising a control circuit configured to determine if contact between the dispensing tip and liquid has occurred based on the sensed sound.

17. 17. The liquid dispenser of claim 15 or 16, wherein the respective cavity and the respective connector of each of the one or more side conduits is free of Helmholtz resonance.

18. 18. The liquid dispenser of claim 17, wherein a lateral dimension of the respective cavity is the same as a lateral dimension of the respective connector for each of the one or more side conduits.

19. A liquid dispenser according to any one of claims 15 to 18, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 100 Hz to 4 kHz.

20. 20. The liquid dispenser of claim 19, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 200 Hz to 1 kHz.

21. 21. A liquid dispenser according to any one of claims 15 to 20, wherein the respective cavity of each of the one or more side conduits is configured to accommodate at least one of the sound generator or the acoustic sensor.

22. 22. The liquid dispenser of claim 21, wherein the one or more side conduits include a single side conduit, and wherein one of the sound generator and the acoustic sensor is housed within the single side conduit, and the other of the sound generator and the acoustic sensor is housed in the dispense chamber portion.

23. 1. A liquid dispenser system, comprising: A liquid dispenser comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a sound generator configured to generate sound to induce acoustic resonance within the dispensing chamber; an acoustic sensor configured to sense sound within the dispense chamber, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion.

24. a liquid dispenser transport device configured to move the liquid dispenser; 24. The liquid dispenser system of claim 23, further comprising: a piston driver configured to drive the piston within the piston chamber.

25. 25. The liquid dispenser system of claim 23 or 24, further comprising a control circuit configured to determine if contact between the dispensing tip and liquid has occurred based on the sensed sound.

26. the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispense chamber; 26. The liquid dispenser system of any one of claims 23 to 25, wherein the respective cavity and the respective connector of each of the one or more side conduits is free of Helmholtz resonance.

27. 27. The liquid dispenser system of claim 26, wherein a lateral dimension of the respective cavity is the same as a lateral dimension of the respective connector for each of the one or more side conduits.

28. 28. The liquid dispenser system of any one of claims 23 to 27, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 100 Hz to 4 kHz.

29. 30. The liquid dispenser system of claim 28, wherein the acoustic resonance in the one or more side conduits is outside the frequency range of 200 Hz to 1 kHz.

30. 30. The liquid dispenser system of any one of claims 26 to 29, wherein the cavity of each of the one or more side conduits is configured to accommodate at least one of the sound generator or the acoustic sensor.

31. 31. The liquid dispenser system of claim 30, wherein the one or more side conduits include a single side conduit, one of the sound generator and the acoustic sensor housed within the single side conduit, and the other of the sound generator and the acoustic sensor housed in the dispense chamber portion.

32. A liquid dispenser, comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a dispenser body including an acoustic filter disposed between the dispense chamber and the piston chamber, the acoustic filter configured to acoustically isolate the dispense chamber from the piston chamber; a sound generator configured to generate a sound in the dispensing chamber; an acoustic sensor configured to sense an acoustic signal resulting from the generated sound.

33. A control circuit comprising: whether contact between the dispensing tip and a liquid has occurred based on the detected sound; or 33. The liquid dispenser of claim 32, further comprising a control circuit configured to determine at least one of: a volume of the liquid in the dispensing tip based on the sensed sound.

34. 34. A liquid dispenser according to claim 32 or 33, wherein the length of the air column resonance in the dispense chamber is unaffected by movement of the piston.

35. The liquid dispenser of any one of claims 32 to 34, wherein the acoustic filter comprises at least one of a sound reflecting filter or a sound absorbing filter.

36. 36. The liquid dispenser of claim 35, wherein the sound reflecting filter is configured to isolate an air column resonance length in the dispense chamber from an air column resonance length in the piston chamber.

37. 37. A liquid dispenser according to claim 35 or 36, wherein the sound reflecting filter is impermeable to air.

38. A liquid dispenser according to any one of claims 35 to 37, wherein the sound absorbing filter is configured to reduce sound caused by movement of the piston.

39. A liquid dispenser according to any one of claims 35 to 38, wherein the sound absorbing filter is air permeable and sound damping.

40. 40. The liquid dispenser of any one of claims 32 to 39, wherein the acoustic filter is made from at least one of open-cell foam, closed-cell foam with air passages, or fibrous material.

41. A liquid dispenser according to any one of claims 32 to 40, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion.

42. the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispense chamber; 42. The liquid dispenser of claim 32, wherein at least one of the sound generator or the acoustic sensor is disposed within the one or more side conduits, and wherein the respective cavity and the respective connector of each of the one or more side conduits is free of resonance within a frequency range of the sound sensed by the acoustic sensor.

43. The control circuit The liquid dispenser of any one of claims 33 to 42, further configured to identify information about the dispensing tip based on the sensed sound.

44. The control circuit 44. The liquid dispenser of claim 32, further configured to determine whether the dispensing tip is fully coupled with the first portion of the dispensing chamber portion based on the sensed sound.

45. 1. A liquid dispenser system, comprising: A liquid dispenser comprising: A dispenser body, a dispense chamber portion including a dispense chamber therein, the dispense chamber having a first opening at a first portion of the dispense chamber portion and a second opening at a second portion of the dispense chamber portion, the first portion configured to mate with a dispense tip; a piston chamber portion including a piston chamber therein, the piston chamber connected to the dispensing chamber through the second opening and configured to direct a piston in linear motion within the piston chamber to draw liquid into and dispense liquid out of the liquid dispenser; a dispenser body including an acoustic filter disposed between the dispense chamber and the piston chamber, the acoustic filter configured to acoustically isolate the dispense chamber from the piston chamber; a sound generator configured to generate a sound in the dispensing chamber; an acoustic sensor configured to sense an acoustic signal resulting from the generated sound; whether contact between the dispensing tip and liquid has occurred, or a volume of the liquid in the dispensing tip based on the sensed sound.

46. a liquid dispenser transport device configured to move the liquid dispenser; 46. ​​The liquid dispenser system of claim 45, further comprising: a piston driver configured to drive the piston within the piston chamber.

47. 47. The liquid dispenser system of claim 45 or 46, wherein the length of the air column resonance in the dispense chamber is not affected by movement of the piston.

48. The liquid dispenser system of any one of claims 45 to 47, wherein the acoustic filter comprises at least one of a sound reflecting filter or a sound absorbing filter.

49. 49. The liquid dispenser system of claim 48, wherein the sound reflecting filter is configured to isolate an air column resonance length in the dispense chamber from an air column resonance length in the piston chamber.

50. 50. The liquid dispenser system of claim 48 or 49, wherein the sound reflective filter is impermeable to air.

51. 51. The liquid dispenser system of any one of claims 48 to 50, wherein the sound absorbing filter is configured to reduce sound caused by movement of the piston.

52. 52. The liquid dispenser system of any one of claims 48 to 51, wherein the sound absorbing filter is air permeable and sound damping.

53. 53. The liquid dispenser system of any one of claims 45 to 52, wherein the acoustic filter is made of at least one of an open-cell foam, a closed-cell foam with air passages, or a fibrous material.

54. 54. The liquid dispenser system of any one of claims 46 to 53, wherein at least one of the sound generator or the acoustic sensor is disposed within the dispense chamber portion.

55. the dispenser body further includes one or more side conduits, each of the one or more side conduits having a respective cavity and a respective connector connecting the respective cavity to the dispense chamber; 55. The liquid dispenser system of any one of claims 45-54, wherein at least one of the sound generator or the acoustic sensor is disposed within the one or more side conduits, and wherein the respective cavity and the respective connector of each of the one or more side conduits is free of resonance within a frequency range of the sound sensed by the acoustic sensor.

56. The control circuit 57. The liquid dispenser system of any one of claims 45 to 56, further configured to identify information about the dispensing tip based on the sensed sound.

57. The control circuit 57. The liquid dispenser system of any one of claims 46 to 56, further configured to determine whether the dispensing tip is fully coupled with the first portion of the dispensing chamber portion based on the sensed sound.

58. 1. A method for detecting contact of a liquid with a liquid dispenser, comprising: obtaining, via an acoustic sensor, a plurality of voltage values ​​associated with sound sensed by the acoustic sensor within a time window; squaring each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculating an average value of the plurality of squared voltage values ​​for the time window; determining whether contact between a dispensing tip of the liquid dispenser and a liquid occurred during the time window based on the average value of the plurality of squared voltage values.

59. Determining whether the contact with the liquid has occurred includes: determining that contact with a liquid has occurred when the average value of the plurality of squared voltage values ​​is less than a threshold value; and determining that contact with a liquid has not occurred when the average value of the plurality of squared voltage values ​​is greater than or equal to a threshold value.

60. 60. The method of claim 58 or 59, wherein the plurality of voltage values ​​are obtained over the time domain.

61. A method according to any one of claims 58 to 60, wherein the plurality of voltage values ​​are obtained across the frequency domain.

62. 62. The method of claim 61 , wherein the plurality of voltage values ​​is obtained over a predetermined frequency band comprising a plurality of frequencies.

63. 63. The method of claim 62, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

64. 64. The method of any one of claims 58 to 63, wherein the sound sensed by the acoustic sensor is sensed from sound traveling within the liquid dispenser.

65. 65. The method of any one of claims 58 to 64, wherein at least one of the acoustic sensor or a sound generator that is the source of the sensed sound is located within the interior of the liquid dispenser.

66. 1. A controller for detecting contact between a liquid dispenser and a liquid, comprising: Memory and a control circuit coupled to the memory and the acoustic sensor, the control circuit configured to sense sound and generate a plurality of voltage values ​​based on the sound sensed within a time window, the control circuit comprising: acquiring the plurality of voltage values ​​via the acoustic sensor; squaring the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculating an average value of the plurality of squared voltage values ​​for the time window; and determining whether contact between the liquid dispenser and liquid occurred during the time window based on the average value of the plurality of squared voltage values.

67. The control circuit determines whether the contact with the liquid has occurred by: determining that contact with a liquid has occurred when the average value of the plurality of squared voltage values ​​is less than a threshold value; and determining that contact with liquid has not occurred when the average value of the plurality of squared voltage values ​​is greater than or equal to a threshold value.

68. 68. The controller of claim 66 or 67, wherein the plurality of voltage values ​​are obtained over the time domain.

69. A controller according to any one of claims 66 to 68, wherein the plurality of voltage values ​​are obtained across the frequency domain.

70. A controller according to any one of claims 66 to 69, wherein the plurality of voltage values ​​are obtained over a predetermined frequency band comprising a plurality of frequencies.

71. 71. The controller of claim 70, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

72. 72. The controller of any one of claims 66 to 71, wherein the sound sensed by the acoustic sensor is sensed from sound traveling within the liquid dispenser.

73. 1. A liquid dispenser system for detecting a gas-liquid boundary, comprising: A liquid dispenser comprising: a sound generator configured to generate a sound within the liquid dispenser; and an acoustic sensor configured to sense an acoustic signal resulting from the generated sound; and a control circuit coupled to the acoustic sensor; obtaining, via an acoustic sensor, a plurality of voltage values ​​associated with sound sensed by the acoustic sensor within a time window; squaring each of the plurality of voltage values ​​to obtain a plurality of squared voltage values ​​for the time window; calculating an average value of the plurality of squared voltage values ​​for the time window; and determining whether contact between a dispensing tip of the liquid dispenser and a liquid occurred during the time window based on the average value of the plurality of squared voltage values.

74. The control circuit determines whether the contact with the liquid has occurred by: determining that contact with a liquid has occurred when the average value of the plurality of squared voltage values ​​is less than a threshold value; and determining that contact with liquid has not occurred when the average value of the plurality of squared voltage values ​​is greater than or equal to a threshold value.

75. 75. The liquid dispenser of claim 73 or 74, wherein the plurality of voltage values ​​are obtained over the time domain.

76. A liquid dispenser according to any one of claims 73 to 75, wherein the plurality of voltage values ​​are obtained across a frequency domain.

77. A liquid dispenser according to any one of claims 73 to 76, wherein the plurality of voltage values ​​are obtained across a predetermined frequency band including a plurality of frequencies.

78. 78. The liquid dispenser of claim 77, wherein the predetermined frequency band has a bandwidth greater than 1 kHz.

79. 79. A liquid dispenser according to any one of claims 73 to 78, wherein the sound sensed by the acoustic sensor is sensed from sound propagating within the liquid dispenser.

80. 1. A liquid dispenser system, comprising: a control circuit configured to provide at least one test signal; a liquid dispenser, the liquid dispenser comprising: a dispenser body including a dispensing chamber therein; a sound generator configured to generate at least one test sound in response to the at least one test signal from the control circuit; an acoustic sensor configured to sense the at least one sound in the dispense chamber and provide at least one response signal to the control circuit; The liquid dispenser system, wherein the control circuitry is configured to compare the at least one response signal to a tip presence threshold signal value to determine the presence of a liquid dispensing tip.

81. The control circuit generating at least one test signal at a target frequency in a chip-free condition; 81. The liquid dispenser system of claim 80, further configured to: determine the tip present threshold signal value based on the at least one response signal received during the tip-absent condition.

82. The control circuit 82. The liquid dispenser system of claim 80 or 81, further configured to output a notification of the presence of the liquid dispensing tip.

83. 1. A method for identifying the presence of a liquid tip dispenser tip implemented in a liquid dispenser system, comprising: providing, by a control circuit, at least one test signal; receiving at least one test signal by a liquid dispenser including a dispenser body having a dispensing chamber, a sound generator, and an acoustic sensor; generating at least one test tone by the tone generator in response to the at least one test signal from the control circuit; sensing at least one sound within the dispensing chamber with the acoustic sensor; providing, by the acoustic sensor, at least one response signal based on the at least one sound to the control circuit; comparing the at least one response signal to a tip presence threshold signal value to determine the presence of a liquid dispensing tip.

84. generating at least one test signal at a target frequency in a chip-free condition; 84. The method of claim 83, further configured to: determine the chip present threshold signal value based on the response signal received during the chip absent condition.

85. 85. The method of claim 83 or 84, further comprising outputting a notification of the presence of the liquid dispensing tip.

86. 1. A liquid dispenser system, comprising: a control circuit configured to provide at least one test signal; a liquid dispenser, the liquid dispenser comprising: a dispenser body including a dispensing chamber therein; a sound generator configured to generate at least one test sound in response to the at least one test signal from the control circuit; an acoustic sensor configured to sense the at least one sound in the dispense chamber and provide at least one response signal to the control circuit; The liquid dispenser system, wherein the control circuitry is configured to compare the at least one response signal to a tip identification metric to determine the identity of the liquid dispensing tip.

87. The control circuit 87. The liquid dispenser system of claim 86, further configured to verify the presence of a liquid dispensing tip.

88. The control circuit 88. The liquid dispenser system of claim 86 or 87, further configured to output a notification of the identity of the liquid dispensing tip.

89. the at least one test signal includes a frequency sweep, and the at least one response signal includes a tip response acoustic spectrum; and The control circuit 89. The liquid dispenser system of any one of claims 86-88, further configured to compare the at least one response signal to a tip identification metric by determining a Pearson correlation coefficient between the tip response acoustic spectrum and one or more stored tip identification acoustic spectra.

90. the at least one test signal includes a frequency sweep, and the at least one response signal includes a response acoustic spectrum; and The control circuit 90. The liquid dispenser system of any one of claims 86 to 89, further configured to compare the at least one response signal to a tip identification metric by matching the response signal to a tip frequency response pattern.

91. 1. A method for determining identity of a liquid dispensing tip in a liquid dispenser system, comprising: providing at least one test signal via a control circuit; receiving the at least one test signal by a liquid dispenser including a dispenser body having a dispensing chamber, a sound generator, and an acoustic sensor; generating, by said sound generator, at least one test tone in response to said at least one test signal from said control circuit; sensing the at least one sound within the dispensing chamber with the acoustic sensor; providing, by the acoustic sensor, at least one response signal in response to the at least one sound; comparing the at least one response signal to a tip identification metric to determine the identity of the liquid dispensing tip.

92. 92. The method of claim 91, further comprising verifying the presence of a liquid dispensing tip.

93. 93. The method of claim 91 or 92, further comprising outputting a notification of the identity of the liquid dispensing tip.

94. The at least one test signal includes a frequency sweep, and the at least one response signal includes a tip response acoustic spectrum, and the method further comprises:

94. The method of any one of claims 91 to 93, further comprising comparing the at least one response signal to a tip identification metric by determining a Pearson correlation coefficient between the tip response acoustic spectrum and one or more stored tip identification acoustic spectra.

95. The at least one test signal includes a frequency sweep and the at least one response signal includes a response acoustic spectrum, and the method includes:

95. The method of any one of claims 91 to 94, further comprising comparing said at least one response signal to a chip identification metric by matching said at least one response signal to a chip frequency response pattern.

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