Systems and methods for the detection and control of charged droplets.

Abstract

This document describes a system and method for detecting the position or trajectory of a charged droplet and / or controlling its orientation during flight. The system and method can be used to determine the position of a charged droplet in real time based on signals induced in electrodes of a sensor surrounding an aperture through which the droplet passes in flight from a source aperture to a target. Signals from the sensor electrodes can be measured and used to determine the droplet's position or trajectory. The system and method can be used to modify the trajectory of the charged droplet in real time, for example, based on a determined position identified as having a trajectory deviating from the target. The trajectory can be modified by applying a voltage to electrodes surrounding the aperture through which the charged droplet passes in flight from a source aperture to a target.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 63 / 154,633, filed February 26, 2021, the entire contents of which are incorporated herein by reference. Background Technology

[0003] The discovery of new and useful materials, the characterization of materials, the testing, and other such procedures can depend on the ability to prepare and characterize new material compositions. Therefore, in addition to testing and analyzing various materials, recent research on the physical, chemical, biological, or other material properties has focused on developing and implementing methods and systems for synthesizing and evaluating potentially useful chemical compounds. In particular, high-speed combinatorial methods have been developed to address the general need in the field for systematic, efficient, and economical materials synthesis techniques, as well as methods for analyzing and screening new materials with useful properties.

[0004] High-speed combinatorial methods typically involve the use of array techniques that require the precise dispensing of fluids, each with precisely known chemical composition, concentration, stoichiometry, reagent ratios, and / or volume. Such array techniques can be used to perform a wide variety of synthetic processes and evaluations. Array techniques can use a large number of different fluids to form multiple reservoirs, which, when properly arranged, create a combinatorial library. To implement combinatorial techniques, numerous fluid dispensing techniques have been explored, such as dot-mapping, pipetting, inkjet printing, and acoustic jetting.

[0005] However, many of these techniques have inherent drawbacks that must be addressed until the required fluid dispensing accuracy and efficiency of combined methods can be achieved. For example, many fluid dispensing systems are constructed using piping networks or other fluid delivery containers. In particular, piping can trap air bubbles, and nozzles can become clogged with trapped particles. As a result, system failures can occur, leading to false results. Furthermore, cross-contamination between storage containers of compound libraries can occur due to insufficient flushing of piping and pipette tips between fluid transfer events. Cross-contamination easily leads to inaccurate and misleading results.

[0006] Acoustic jetting offers numerous advantages over other fluid dispensing technologies. Compared to inkjet devices, nozzle-less or tip-less fluid jetting devices are not susceptible to clogging and its associated drawbacks, such as misdirected fluid or improperly sized droplets. Furthermore, acoustic jetting eliminates the need for tubing or invasive mechanical actions, such as those associated with introducing a pipette tip into a fluid reservoir, thus reducing the risk of contamination, among other things. Additionally, acoustic jetting allows for higher levels of precision and accuracy and can be used to dispense very small volumes of fluid, which can significantly reduce reagent costs.

[0007] Acoustic jetting has been described in numerous patents. For example, U.S. Patent No. 4,308,547 to Lovelady et al. describes a droplet ejector that uses acoustic principles to jet droplets from a liquid body onto a moving document, thereby forming characters or barcodes thereon. This is achieved using a nozzleless inkjet printing apparatus, where controlled ink droplets are propelled by acoustic forces generated by a flexural transducer located at or below the ink surface. Similarly, U.S. Patent No. 6,666,541 describes an apparatus for acoustically jetting multiple fluid droplets onto discrete sites on a substrate surface for deposition. This apparatus includes an acoustic radiation generator that can be used to jet fluid droplets from a reservoir and generate detection acoustic waves that are transmitted to the fluid surface of the reservoir to become reflected sound waves. The characteristics of the reflected acoustic radiation can then be analyzed to assess the level of acoustic energy generated by the acoustic radiation generator on the fluid surface. Therefore, acoustic jetting can provide the additional advantage of providing feedback related to the process of acoustic jetting itself, as the correct use of acoustic radiation provides this feedback.

[0008] In addition to changes in forces on the droplet during its flight path (such as air resistance and electrostatic forces on charged droplets), changes in the initial conditions for droplet formation at the meniscus (including droplet velocity and direction) lead to changes in the droplet position at the target.

[0009] When the target is a microplate aperture and multiple droplets are transferred, it is desirable for all droplets to fuse and merge into a single larger droplet at the target. However, in some cases, droplets fall onto the target in a scattering pattern.

[0010] Many existing solutions rely on passive methods to minimize sources of variation. Some example techniques “suppress” menisci and reduce fluid surface variability, but these are not “global” solutions. Typical existing solutions involve some type of calibration solution for non-real-time droplet placement verification, which can be a time-consuming manual process. For example, fluid-sensitive paper can be used to determine where a droplet lands after a test droplet ejection. This non-real-time process, in addition to being time-consuming and labor-intensive, does not allow for timely adjustments and can incur considerable costs in some cases due to droplet ejection failures. While some existing solutions can provide real-time verification of droplet placement, these solutions involve the use of large, expensive, and complex machinery. For example, some optical systems (such as phase Doppler interferometer systems) can be used to detect droplet position in real time, but these are bulky, expensive, and often use laser systems that are ideally avoided.

[0011] There is a need in the art for improved methods and apparatus that can accurately detect droplet ejection, droplet velocity and droplet position during transport, providing real-time data that does not rely on bulky and expensive optical lasers. Summary of the Invention

[0012] Examples of the invention covered by this disclosure are defined by the following claims rather than by this summary. This summary is a high-level overview of various aspects and introduces some concepts that are further described in the detailed description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by referring to the entire disclosure, including the following description, all drawings, and each claim.

[0013] While typical systems rely on manual calibration and / or bulky, expensive optical tracking systems for droplet ejection tracking in acoustic droplet ejectors, the apparatus, systems, and methods presented herein enable real-time tracking and control of charged droplets using compact and low-cost systems. Although the examples described herein are for illustrative or reference purposes regarding acoustic droplet ejection systems, the techniques and systems described herein can be applied to pressure-based systems (e.g., inkjet), microfluidic systems, or any other suitable droplet generation system or component (e.g., fluorescence-activated cell sorters, fluorescence-activated single-droplet dispensers, precision micropump systems, piezoelectric-based active droplet generators, etc.). While real-time tracking can be achieved using optical tracking systems, such systems can add additional complexity to droplet ejection systems and may affect system availability. Other techniques for non-real-time tracking may require manual calibration and workflow interruptions. The real-time measurements described herein provide increased manufacturing workflow efficiency and rapid optimization of droplet generator calibration. The real-time control scheme described herein further provides accuracy and repeatability of droplet position, avoiding repetitive calibration via real-time feedback systems. This system and method can also allow for efficient coupling of droplet generators (e.g., acoustic droplet ejection systems) with inlets of auxiliary devices such as mass spectrometers or other analytical systems. The apparatus, systems, and methods described herein are particularly useful for real-time tracking and control, such as verifying or aligning droplet placement in a mass spectrometer or other analytical system during sample placement for analysis.

[0014] This disclosure provides systems for detecting, monitoring, and controlling charged droplets from a droplet generator, such as acoustic droplet ejection systems. One general aspect includes means for detecting and / or controlling charged droplets from a droplet generator. The means may include a sensor or control element (e.g., a multilayer printed circuit board) having one or more conductive layers separated or supported by insulating layers, the sensor or control element defining an aperture through which the charged droplet passes. In some instances, the sensor or control element may be fabricated as a multilayer printed circuit board, although those skilled in the art will understand that the sensor or control element can take any suitable form. In some instances, droplets ejected by the droplet generator may need to reach a target within specific tolerances. For example, a particular application may employ placement tolerances, such as within a dimension of a portion of the droplet diameter (e.g., within 100%, 75%, 50%, 25%, 10%, or 5% of the droplet diameter). Such placement tolerances may, for example, ensure that the droplet reaches the target or that different droplets merge upon reaching the target. In some cases, droplets may reach a distance of approximately 200% or less from the target droplet diameter (e.g., a 2.5 nL droplet with a diameter of 168 micrometers may reach a distance of 400 micrometers from the target). Preferably, droplets fall uniformly at the target location, or within 125% or less of the droplet diameter from the target location, with fewer than one droplet out of every 1000 falling at a distance greater than 125% of the droplet diameter from the target location. Following the first droplet, subsequent droplets directed to the target location ideally merge, coalesce, and mix into a single, larger droplet. Ideally, there should be no droplets deviating from the target, no scattering, and no spray falling isolated from the main droplet. The placement of the droplets on the target can tolerate the widest possible range of initial velocity and direction at the time of droplet formation, as well as fluctuations along the droplet's flight path. In some instances, the target may be an inlet or orifice associated with a pore in a microplate, microfluidic device, or analytical instrument, apparatus, or system. The size of the droplets can be adjusted to properly reach the target without impacting the sides or walls of the inlet or orifice. For example, the orifice may have a diameter greater than or about 130% of the droplet diameter, such as greater than or about 150%, 200%, 250%, 300%, 350%, 400%, 450%, 500%, or about 130% to about 1000% of the droplet diameter.

[0015] In some instances, the sensor element may include three or more conductive layers and two or more insulating layers. In one instance, the inner layer of the sensor element may include a segmented conductive layer having multiple separate segments electrically isolated or independent of each other, the multiple separate segments being arranged around the periphery of an aperture at the segmented conductive layer. The device may also include a circuit element (e.g., one or more transimpedance amplifiers) electrically coupled to each separate segment. Each separate segment of the sensor element is positioned to provide an induced current to the circuit element when a charged droplet passes through the aperture. The circuit element may include one or more transimpedance amplifiers that generate a measurement (e.g., a voltage signal) proportional to the induced current. The device may also include one or more computing devices or tools that can receive the measurement from the circuit element and generate a weighted map based on the magnitude of the measurement to identify the position of the charged droplet within the aperture. In some instances, the signal may be processed using computing devices, circuitry, analog-to-digital converters, software, or other such systems.

[0016] In some instances, the control element may include one or more conductive layers and one or more insulating layers. In one instance, the conductive layer of the control element may include a segmented conductive layer having multiple separate segments electrically isolated or independent of each other, the multiple separate segments arranged around the periphery of an aperture at the segmented conductive layer. The device may also include one or more voltage generators and / or voltage controllers for applying a potential to each separate segment to generate an electric field of direction and magnitude sufficient to alter the trajectory of a charged droplet as it passes through the aperture. The device may also include one or more computing devices or tools that can determine the voltage applied to each separate segment to achieve a specific deflection of the droplet trajectory. In some cases, the voltage may be determined based on or using the position of the charged droplet, or a signal representing or contributing to the determination of the position of the charged droplet, which is determined by passing the charged droplet through a sensor element. In some instances, computing devices, circuits, analog-to-digital converters, software, or other such systems may be used to process the signal to determine the appropriate voltage applied to the separate segments of the conductive layer.

[0017] In other examples, a system for detecting charged droplets from a droplet generator may include a sensing device having an aperture formed therein from a first surface to a second surface. The sensing device includes a first conductive layer at the first surface, a second conductive layer at the second surface, a segmented sensor layer between the first and second conductive layers, and first and second dielectric layers positioned on opposing surfaces of the segmented sensor layer to insulate the segmented sensor layer from the first and second conductive layers. The segmented sensor layer may include a plurality of segments positioned around the periphery of the aperture. The system may also include circuitry coupled to each of the plurality of segments of the segmented sensor layer. In some examples, the circuitry includes one or more transimpedance amplifiers. The system may also include a processor and a non-transitory computer-readable medium having instructions stored thereon that, when executed by the processor, cause the processor to perform operations including: receiving from one or more circuitry elements coupled to the segmented sensor layer a plurality of measurements corresponding to induced currents passing through segments of the segmented sensor layer as the charged droplet passes through the aperture; and determining the position of the charged droplet based on the measurements.

[0018] In other examples, a system for detecting charged droplets from a droplet generator may include a control device having an aperture formed therein and including a segmented conductive layer. The segmented conductive layer may include a plurality of segments positioned around the periphery of the aperture. The system may also include a voltage controller coupled to each of the plurality of segments of the segmented conductive layer. In some examples, the voltage controller may be driven to generate a potential at each segment of the conductive layer, thereby establishing an electric field at the aperture. The system may also include a processor and a non-transitory computer-readable medium having instructions stored thereon that, when executed by the processor, cause the processor to perform operations including: applying a set of control voltages to the plurality of segments using the voltage controllers to control the trajectory of the charged droplet as it passes through the aperture. For example, the set of control voltages may be generated based on the determined position or velocity of the charged droplet.

[0019] In another aspect, this document describes methods, such as methods for detecting or controlling charged droplets (e.g., from a droplet generator). In some instances, the methods may be performed by or using the systems described herein. In some instances, the methods of this aspect may include positioning a charged droplet detector and / or a charged droplet controller between a droplet generator and a target, guiding a charged droplet from the droplet generator to the target and through an aperture of the charged droplet detector and / or the charged droplet controller. The methods of this aspect may include analyzing a voltage signal generated by the charged droplet detector as the charged droplet passes through the aperture to determine the position of the charged droplet. The methods of this aspect may include determining and / or applying a voltage to a segment of a segmented control layer to alter the trajectory of the charged droplet, for example, by determining the voltage based on a signal from which the position of the charged droplet can be derived. Other examples of this aspect include corresponding means and systems, each configured to perform the actions of the methods. Optionally, the methods or portions thereof disclosed may be executed during the execution of processor-executable instructions.

[0020] In another aspect, this document describes a method for adjusting ejection parameters in an acoustic droplet ejection system based on detected charged droplets. In some instances, the method is performed using a system described herein, including an acoustic droplet ejection system, a sensing element, and other systems described herein. The method may include applying an acoustic signal to a fluid using an acoustic droplet ejection system coupled to a reservoir to cause a first droplet to be ejected from the reservoir, directed toward a target, through an aperture of a charged droplet detector. The method may also include determining, based on measurements corresponding to the value of an induced current passing through the charged droplet detector, that the acoustic signal has caused the ejection of a satellite droplet. The method may further include, based on said determination, adjusting parameters of the acoustic droplet ejection system to prevent or reduce the ejection of satellite droplets in subsequent ejections. In some instances, the method or portions thereof disclosed may be executed during the execution of processor-executable instructions. Attached Figure Description

[0021] A further understanding of the nature and advantages of the various embodiments can be achieved by referring to the following accompanying drawings. In the drawings, similar parts or features may have the same reference numerals.

[0022] Figure 1 A droplet generator including an electrified droplet management device is shown according to at least some examples.

[0023] Figure 2 A droplet generator comprising a charged droplet detector and a charged droplet controller is shown according to at least some examples.

[0024] Figure 3 An exploded view of the conductive layer of a charged droplet detector according to at least some examples is shown.

[0025] Figure 4 A side view of a charged droplet detector based on at least some examples is shown.

[0026] Figure 5 A top view of a segmented conductive layer of a charged droplet detector according to at least some examples is shown.

[0027] Figure 6 A cross-sectional view of a charged droplet detector demonstrating electrical connections of a conductive layer, based on at least some examples, is shown.

[0028] Figure 7 An exploded view of the layers of a charged droplet controller based on at least some examples is shown.

[0029] Figure 8 A side view of an charged droplet controller based on at least some examples is shown.

[0030] Figure 9 A top view of a segmented conductive layer of an charged droplet controller according to at least some examples is shown.

[0031] Figure 10 A cross-sectional view of a charged droplet controller demonstrating electrical connections of a conductive layer, based on at least some examples, is shown.

[0032] Figure 11 A graph showing the differential current from the relative segments of the segmented conductive layer for different droplet displacement positions along the axis between the relative segments is shown, based on at least some examples.

[0033] Figure 12 A graph illustrating the current from a segment of a segmented conductive layer, based on at least some examples, is shown, with the current generated due to charged droplets passing through the holes.

[0034] Figure 13 The diagram illustrates, according to at least some examples, the voltage signal associated with the output from the transimpedance amplifier in an instance where a charged droplet is placed inside a hole.

[0035] Figure 14 The voltage signal output of the detector signal for a droplet passing through an orifice is shown according to at least some examples.

[0036] Figure 15 The following are examples shown. Figure 14 The representation of the position of the droplets.

[0037] Figure 16 The voltage signal output of the detector signal for the main droplet and satellite droplets passing through the orifice is shown according to at least some examples.

[0038] Figure 17The following are examples shown. Figure 16 The representation of the positions of the main droplet and satellite droplets.

[0039] Figure 18 A flowchart illustrating a process for detecting charged droplets ejected from a droplet generator, based on at least some examples, is shown.

[0040] Figure 19 A top view of the conductive layer of an charged droplet controller according to at least some examples is shown.

[0041] Figure 20 , Figure 21 and Figure 22 The diagram shows the relative positions of charged droplets as measured by two charged droplet detectors on opposite sides of the charged droplet controller during the manipulation of charged droplets by applying different voltage differences between segments of the charged droplet controller.

[0042] Figure 23 A flowchart illustrating, based on at least some examples, is shown for controlling the ejection of charged droplets from a droplet generator.

[0043] Figure 24 A flowchart illustrating, based on at least some examples, a process for using a feedback mechanism to detect and control charged droplets ejected from a droplet generator is shown.

[0044] Figure 25 A block diagram of an example computing device is shown, based on some examples.

[0045] Figure 26 An overview of examples of charged droplet ejection, detection, and control systems is provided, based on several instances. Detailed Implementation

[0046] This disclosure describes apparatus, systems, and methods for real-time detection, monitoring, and / or control of charged droplets using compact, low-cost devices. Numerous benefits can be achieved through the disclosed systems and methods, including the detection of the horizontal position of charged droplets (e.g., along the X and Y axes), measurement of droplet velocity, detection of satellite droplets, measurement of droplet charge, droplet counting, droplet tracking, and droplet trajectory control. In some instances, the apparatus, systems, and methods described herein can be used for diagnostic measurements to align droplet generators, detect directional errors in the trajectory of ejected droplets, and / or correct directionally erroneous ejected droplets. Advantageously, these aspects can be performed in real-time during droplet generation and can be used to provide feedback to modify or adjust system components, alignment, ejection parameters, etc.

[0047] In some instances, the charge possessed by a droplet (droplet charge) can be correlated with the volume of a specific source fluid, allowing measurements of the droplet charge of multiple droplets to be used to predict and / or determine droplet volume. While typical systems rely on manual calibration and / or bulky and expensive optical tracking systems, the apparatus, systems, and methods presented herein enable real-time tracking and / or control of charged droplets using compact and low-cost systems. The real-time measurements achieved herein provide increased manufacturing workflow efficiency and rapid optimization of droplet generators, such as for calibration of acoustic droplet ejection systems. The disclosed systems and methods also allow for efficient coupling and precise alignment of the droplet generator with the inlet of auxiliary devices such as mass spectrometers or other analytical systems. The apparatus, systems, and methods described herein are particularly useful for real-time tracking, such as validating droplet placement in a mass spectrometer or other analytical system during sample placement for analysis. The apparatus, systems, and methods described herein can also be used for real-time control of droplet trajectories, optionally employing feedback mechanisms, where droplet position and / or trajectory are determined and the droplet trajectory is adjusted, for example, to optimize droplet placement in a mass spectrometer or other analytical system during sample placement for analysis.

[0048] Droplet generation can include processes such as acoustic droplet ejection, in which droplets are acoustically actuated from a fluid reservoir and travel toward a target surface or location; however, this disclosure is not limited to droplet generation using acoustic droplet ejection systems. Other systems, such as pressure-based, inkjet, and / or microfluidic droplet generators or ejection systems, can be used. In some embodiments of acoustic droplet ejection, acoustic energy can be directed to the fluid constriction of a reservoir containing fluid within a sample container (e.g., a pore of a microplate, a fluid sample tube, a microplate, a microfluidic device) or to the inlet of an analytical instrument, system, or device (including a mass spectrometer or other instruments used for analyzing chemical composition, genomic contents, genome sequencing, particle size analyzers, body fluids, cell analysis (e.g., cell counters, hemocytometers), etc.). In some embodiments, the droplet generator can be oriented such that the droplet travels vertically upward toward the target surface or location. Although droplets are described herein as moving upward, in implementing the systems and methods described herein, droplets can be transported in other directions besides upward, such as downward and / or laterally. In acoustic droplet ejection systems, the droplet trajectory from the ejected fluid meniscus to the target surface may deviate from its intended path, at least in part, due to static effects (e.g., tilted fluid meniscus, electrostatic charge in the orifice plastic) and dynamic effects (e.g., capillary waves in the orifice), resulting in an incorrect droplet orientation at the target surface / destination. Similar orientation errors may occur in other droplet generation systems due to static and / or dynamic effects. The systems and methods described herein enable real-time measurement of droplet orientation errors, thereby allowing for the monitoring and, optionally, reduction of droplet orientation errors, for example, by implementing droplet control schemes that adjust the droplet trajectory.

[0049] When the target is a microplate aperture and multiple droplets are being transferred, it may be desirable for all droplets to fuse and merge into a single, larger droplet at the target location. However, in some cases, droplets ejected by a droplet generator can reach the target location within specific tolerances. For example, a particular application might employ placement tolerances, such as within a dimension of the droplet diameter (e.g., within 100%, 75%, 50%, 25%, 10%, or 5% of the droplet diameter). Such placement tolerances can, for example, ensure that the droplets reach the target or that different droplets merge upon reaching the target. In some cases, droplets may reach a distance of approximately 200% or less from the target droplet diameter (e.g., a 2.5 nL droplet with a diameter of 168 micrometers may reach a distance of 400 micrometers from the target). In preferred cases, droplets land uniformly at the target location, or at a distance of 125% or less of the droplet diameter from the target location, with fewer than one droplet out of every 1000 landing at a distance greater than 125% of the droplet diameter from the target location. Following the first droplet, subsequent droplets directed to the target location ideally merge, coalesce, and mix into a single, larger droplet. Ideally, there should be no droplets deviating from the target, no scattering, and no spray falling isolated from the main droplet. The placement of the droplet on the target can tolerate the widest possible range of initial velocity and direction at the time of droplet formation, as well as fluctuations along the droplet's flight path. In some instances, the target may be an inlet or orifice associated with a pore in a microplate, microfluidic device, or analytical instrument, apparatus, or system. The size of the droplet can be adjusted to properly reach the target without impacting the sides or walls of the inlet or orifice. For example, the orifice may have a diameter greater than or approximately 130% of the droplet diameter, such as greater than or approximately 150%, 200%, 250%, 300%, 350%, 400%, 450%, 500%, or approximately 130% to approximately 1000% of the droplet diameter.

[0050] In some cases, the target may be associated with a mass spectrometer (e.g., the open port probe (OPP) interface of a mass spectrometer) or other analytical instruments or systems. The opening of the OPP may be defined at least partially by the coaxial arrangement of the capillary and the housing (along the capillary axis). In some such cases, a droplet placement tolerance of less than or approximately 125% of the droplet diameter from the vortex core (capillary axis) is a desirable feature to ensure accurate droplet placement within the OPP. In these cases, droplet placement exceeding 125% of the droplet diameter from the target location can result in lower ion counts and higher charge volumes at the mass spectrometer. Droplet placement greater than or approximately 200% or 250% of the droplet diameter can result in lost ion count peaks.

[0051] According to the examples described herein, a charged droplet management system may be located between a target and a droplet generator, for example, between the target and a source orifice of an acoustic droplet ejection system. The charged droplet management system may include an orifice aligned with the ejection axis of the droplet generator (e.g., the transducer axis of the ejection system) such that droplets ejected by the droplet generator pass through the orifice toward the target. The charged droplet management system may include one or both of a sensing or detector component and / or a control component. In either case, the charged droplet management system may include a plurality of segmented electrodes surrounding the orifice.

[0052] For use as a charged droplet detector, a current is induced in each segmented electrode as a charged droplet passes through the aperture, and circuitry is used to convert the current in each segment into a corresponding output value to detect the current. The output value may correspond to the induced current or represent a voltage value proportional to the induced current. In some instances, the circuitry may include one or more transimpedance amplifiers. Although the description herein may refer to a transimpedance amplifier, other suitable circuitry may be implemented instead. Since the geometry of the sensor components and the aperture is known and predetermined, the induced current can be modeled and determined. For example, the Ramo-Shockley theorem can be used to determine the droplet charge, velocity, and / or trajectory based on the current induced in the segmented electrodes. In particular, the sum of all values, such as the induced current (and therefore the transimpedance amplifier voltage), can be directly correlated with the droplet charge and velocity. Additionally, the signal differences from the relative segments around the aperture can be used to determine the lateral position of each droplet as it passes through the aperture.

[0053] For use as a charged droplet controller, a voltage can be applied to each segmented electrode as the charged droplet passes through the orifice to generate an electric field that applies a force to the charged droplet, thereby modulating its trajectory. Various configurations of the segmented electrodes can be used, for example, to allow precise adjustment of the charged droplet trajectory along two axes (e.g., the X and Y axes). The voltage can be applied by one or more voltage controllers or other suitable components that can be implemented as or replace voltage controllers.

[0054] Figure 1 A system 111 with an charged droplet management device 110 is shown according to at least some examples. As with all appendices referenced herein. Figure 1 Sample, Figure 1 This is not drawn to scale, and some dimensions may be enlarged for clarity. The system 111 shown includes a droplet generator 101 for generating charged droplets. Figure 1 In this document, droplet generator 101 is described as an acoustic droplet ejection system, but such configuration is not limited and other droplet generators may be used without departing from the aspects described herein. Figure 1The system 111 shown is configured to receive a sample container 112 (optionally separate from the system 111), which may be a consumable (e.g., a microplate, fluid sample tube, or orifice plate) having one or more reservoirs. For example, the sample container 112 may include multiple reservoirs, i.e., two or more reservoirs, a first reservoir indicated by 113, a second reservoir indicated by 115, each adapted to contain a fluid having a fluid surface, such as a first fluid 114 and a second fluid 116 having fluid surfaces indicated by 117 and 119, respectively. The first fluid 114 and the second fluid 116 may be the same or different. In some instances, the sample container 112 may include only a single reservoir, where the systems and methods of this invention enable verification of successful droplet ejection, tracking of droplet misdirection, and control of droplets from a single reservoir, although the systems and methods may be conceived as ejecting, tracking, and / or controlling droplets from multiple reservoirs. As shown, the reservoirs have substantially the same structure, and are thus substantially acoustically indistinguishable, but such identical structure is not required. The reservoirs are shown as individual removable components, but can be fixed within a plate or other substrate if desired. For example, multiple reservoirs may comprise individual holes in an orifice plate, which may (though not necessarily) be arranged in an array. Each of reservoirs 113 and 115 is preferably axially symmetrical as shown, having vertical walls 121 and 123 extending upward from reservoir bases 125 and 127 and terminating at openings 129 and 131, respectively. The material and thickness of each reservoir base may be such that acoustic radiation can be transmitted through it and enter the fluid contained within the container.

[0055] System 111 includes an acoustic ejector 133, which includes an acoustic radiation generator 135 for generating acoustic radiation and a focusing device 137 for focusing the acoustic radiation into the fluid from which droplets are to be ejected, near the fluid surface. Figure 1 As shown, the focusing device 137 may include a single solid element having a concave surface 139 for focusing acoustic radiation, but the focusing device 137 may be constructed in other ways as described below. Thus, the acoustic ejector 133 is adapted to generate and focus acoustic radiation so that droplets of fluid are ejected from each fluid surface 117 and 119 when acoustically coupled to reservoir orifices 113 and 115 and thus to the first fluid 114 and the second fluid 116, respectively. The acoustic radiation generator 135 and the focusing device 137 may operate as a single unit controlled by a single controller, or they may be controlled independently, depending on the desired performance of the device. Typically, a single ejector design is preferred over a multiple ejector design because it is easier to achieve accuracy in droplet arrangement and consistency in droplet size and velocity with a single ejector; however, this disclosure contemplates the possibility of using multiple ejectors as well.

[0056] It is understood that any of the various focusing devices 137 can be used in conjunction with the present invention. For example, one or more curved surfaces can be used to direct acoustic radiation to a focal point near a fluid surface. Such a technique is described in U.S. Patent No. 4,308,547 to Lovelady et al. Focusing devices 137 with curved surfaces have been incorporated into structures such as those manufactured by OLYMPUS CORP. (Waltham, Mass.). Furthermore, Fresnel lenses are known in the art for directing acoustic energy to a predetermined focal length from an object plane. See, for example, U.S. Patent No. 5,041,849 to Quate et al. Fresnel lenses may have a radial phase distribution that diffracts most of the acoustic energy into predetermined diffraction orders with a diffraction angle varying relative to the radial direction of the lens. The diffraction angle can be selected to focus the acoustic energy within the diffraction order onto the desired object plane.

[0057] In operation, such as Figure 1 As shown, the reservoir holes 113 and 115 of the device are each filled with a first fluid 114 and a second fluid 116, respectively. The acoustic jet 133 can be positioned using a jet positioner 143, which may include, for example, an actuator capable of moving the acoustic jet 133 to a desired position to achieve acoustic coupling between the jet and the reservoir via an acoustic coupling medium 141. Figure 1 In this embodiment, substrate 145 is shown positioned above and near the first reservoir aperture 113, such that one surface of the substrate faces the reservoir and is arranged substantially parallel or opposite to the fluid surface 117 of the first fluid 114 therein. In some embodiments, substrate 145 may be a sample container (e.g., a microplate, sample tube) that includes a target area for droplet ejection. Once the ejector, reservoir, and substrate are properly aligned, acoustic radiation generator 135 is activated to generate acoustic radiation directed by focusing device 137 to a focal point 147 at or near the fluid surface 117 of the first reservoir. As a result, droplets 149 are ejected from the fluid surface 117 onto a designated site on the underside surface of substrate 145, which includes aperture 155. In some cases, surface tension or capillary forces may help or cause the ejected droplets to remain on the substrate surface. Although not explicitly stated in the original text... Figure 1 As shown, however, this disclosure envisions that an interface to an analytical apparatus, system, or instrument (such as a mass spectrometer (e.g., OPP)) or any other suitable target could replace substrate 145.

[0058] System 111 includes a substrate positioning device 150, which can be adjusted to reposition substrate 145 above reservoir 115 to receive droplets therefrom at a second designated location. For example, acoustic ejector 133 can be repositioned below reservoir 115 by ejector positioning device 143 and is acoustically coupled to reservoir 115 by means of acoustic coupling medium 141. Once properly aligned, acoustic radiation generator 135 of acoustic ejector 133 can be activated to generate acoustic radiation, which is then directed by focusing device 137 to a focal point 148 at or near the fluid surface 119 of second fluid 116, thereby ejecting additional droplets onto substrate 145 at well 157. It should be understood that this operation illustrates how the device can be used to eject multiple fluids from reservoirs to form patterns, such as arrays, on substrate 145. It should also be understood that the device can be adapted to eject multiple droplets from one or more reservoirs to the same location on substrate 145.

[0059] although Figure 1 A specific configuration is shown, but this disclosure contemplates any suitable configuration in which the disclosed concepts can be easily modified accordingly. For example, the 111 system can be oriented in different ways (e.g., the acoustic jet 133 is positioned above the substrate 145 to spray droplets downwards, or the acoustic jet 133 is positioned on the side of the substrate 145 to spray droplets laterally).

[0060] As shown in the figure, system 111 includes a charged droplet management device 110 capable of sensing, detecting, characterizing, deflecting, and / or manipulating the velocity or direction of a charged droplet passing through it. In some embodiments, as further described below, the charged droplet management device 110 may include one or more conductive layers. In some embodiments, system 111 may apply or impart a charge to droplet 149 before, during, or after ejection. Thus, droplet 149 may carry a net charge. The net charge can be induced on the droplet by applying a voltage to one or more layers of the charged droplet management device 110. The voltage can generate an electric field at the fluid concave surface that induces the net charge on the ejected droplet. In some instances, the natural charge of the droplet can be measured without an external electric field. Such a net charge can be imparted, for example, by applying a voltage or charge (e.g., a 1.5 kV bias) directly to... Figure 1 The fluid 114 causes the droplets to pass through an additional bias conductive layer located between the reservoir and the charged droplet management device 110, which is maintained at a reference voltage (e.g., a high voltage), or biases all or part of the voltage of the charged droplet management device 110.

[0061] The charge imparted to the charged droplet can be positive or negative, depending on the voltage and / or electric field at the fluid 114 or meniscus. Optionally, the polarity of the charge imparted to the droplet can be changed, for example, from positive to negative or from negative to positive. The polarity can be changed by adjusting the voltage and / or electric field at the fluid or meniscus during droplet generation, for example, by switching the polarity of the voltage. The polarity can be changed periodically or non-periodically. In some cases, changing the polarity during droplet generation can allow for a reduction in charge accumulation at the target (e.g., substrate 145), because a negatively charged droplet can eliminate previously accumulated positive charge at the target and / or a positively charged droplet can eliminate previously accumulated negative charge at the target. To sense or control the charged droplet by the charged droplet management device 110, operation using a voltage suitable for detecting or controlling positively or negatively charged droplets can be synchronized with the polarity of the generated droplet. To guide charged droplets into a mass spectrometer or other analytical system, the operation of the mass spectrometer or other analytical system used to analyze positively or negatively charged droplets can be synchronized with the polarity of the generated droplets.

[0062] The charged droplet manipulator 110 includes an aperture 109 through which a droplet 149 travels from a first reservoir aperture 113 to an aperture 155. The aperture 109 is aligned with the transducer shaft 118 of the acoustic ejector 133. Without limitation, the aperture of the charged droplet manipulator can have a diameter of 1 mm to 5 mm or greater, such as 1 mm to 1.5 mm, 1.5 mm to 2 mm, 2 mm to 2.5 mm, 2.5 mm to 3 mm, 3 mm to 3.5 mm, 3.5 mm to 4 mm, 4 mm to 4.5 mm, or 4.5 mm to 5 mm. In some instances, the aperture of the charged droplet manipulator can have a diameter larger than the droplet diameter, for example, where the aperture has a diameter greater than or approximately 120% of the droplet diameter or less than approximately 500% of the droplet diameter. Without limitations, the orifice may have a diameter greater than or approximately 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 225%, 250%, 275%, 300%, 325%, 350%, 375%, 400%, 425%, 450%, 475%, or 500% of the droplet diameter. In some cases, the orifice diameter may be greater than 500% of the droplet diameter; for example, the orifice diameter may be as large as 3000% or 5000% of the droplet diameter, or even larger.

[0063] In some instances, the charged droplet management device 110 may be positioned parallel to or at an angle relative to the surface of the first reservoir aperture 113. In some instances, the charged droplet management device 110 may be positioned diagonally relative to the first reservoir aperture 113.

[0064] The charged droplet management device 110 can be used to sense, detect, or characterize charged droplets in a configuration referred to herein as a charged droplet detector or charged droplet sensor. The charged droplet management device 110 can alternatively or additionally be used to control the direction, velocity, or trajectory of charged droplets in a configuration referred to herein as a charged droplet controller. The charged droplet detector or charged droplet sensor can be advantageously used to identify the position of a charged droplet passing through the aperture 109, for example, to determine the lateral (e.g., X, Y) position of the charged droplet. Furthermore, the charged droplet detector can be used to determine velocity, droplet timing (e.g., arrival at the aperture), total droplet charge, and / or the presence of one or more charged satellite droplets. The charged droplet controller can be advantageously used to regulate the trajectory of the charged droplet, for example, by manipulating the charged droplet (e.g., by generating a lateral deflection) by applying a force (e.g., a pulsed force).

[0065] A feedback system may be included with or as part of the charged droplet management device 110 to allow the use of a charged droplet detector to determine the lateral position of the charged droplets and to provide a steering signal, such as a voltage signal determined based on the lateral position of the charged droplets, to the charged droplet controller. In this way, the charged droplet management device 110 can identify misaligned charged droplets and adjust their trajectories so that they are received at the intended target location. For example, as described in further detail below, the charged droplet detector component of the charged droplet management device 110 may be used to generate current and / or voltage waveforms by allowing charged droplets to pass through them, and to provide such waveforms to a signal processing component to extract the position of the charged droplets at the charged droplet detector. The position of the charged droplet detector may be further analyzed and / or used, for example by signal processing or other processing components, to determine the appropriate steering voltage applied to the charged droplet controller component of the charged droplet management device 110. In some instances, a lookup table or function can be used to determine the operating voltage, where the position is provided as input and the operating voltage is provided as output.

[0066] In some instances, both charged droplet detectors and charged droplet controllers can be used, either integrated into a single charged droplet management device or as separate components. Figure 2 An exemplary system 211 is shown, which can be used with Figure 1The system 211 shown may be the same as or different from system 111. In addition to the other components shown in system 111, including droplet generator 101 and substrate 145, system 211 also includes a charged droplet detector 210A and a charged droplet controller 210B. In the illustrated configuration, the charged droplet detector 210A is located closer to the droplet generator 101, and the charged droplet controller 210B is located closer to the substrate 145. Their apertures 209A and 209B are arranged relative to each other such that the droplet 249 passes through both apertures 209A and 209B as it travels along axis 218 toward substrate 145. This configuration is not intended to be limiting. For example, the charged droplet controller 210B may alternatively be positioned closer to the droplet generator 101, while the charged droplet detector 210A may be positioned closer to the substrate 145. In some instances, only the charged droplet detector 210A is used, and the charged droplet controller 210B is not present. In other instances, only the charged droplet controller 210B is used, and the charged droplet detector 210A is not present. Optionally, multiple charged droplet detectors 210A may be used. Optionally, multiple charged droplet controllers 210B may be used. In some instances, two charged droplet detectors 210A may be used with a single charged droplet controller 210B between them. In some instances, this configuration may be used for detecting the charged droplet position by a first charged droplet detector, modifying the charged droplet trajectory by the charged droplet controller, and detecting the charged droplet position by a second charged droplet detector after the trajectory modification. Any suitable spacing or distance between the components of the charged droplet management device (e.g., between the charged droplet detector 210A and the charged droplet controller 210B) may be used. In some instances, the spacing between the charged droplet detector 210A and the charged droplet controller 210B may be 25% to 400% of the diameter of the aperture 209A and / or the aperture 209B. In some instances, the spacing between components of a charged droplet management system (e.g., a charged droplet detector and / or a charged droplet controller) can be 0.1 mm to 10 mm or greater, such as 0.1 mm to 0.5 mm, 0.5 mm to 1 mm, 1 mm to 1.5 mm, 1.5 mm to 2 mm, 2 mm to 2.5 mm, 2.5 mm to 3 mm, 3 mm to 3.5 mm, 3.5 mm to 4 mm, 4 mm to 4.5 mm, 4.5 mm to 5 mm, 5 mm to 5.5 mm, 5.5 mm to 6 mm, 6 mm to 6.5 mm, 6.5 mm to 7 mm, 7 mm to 7.5 mm, 7.5 mm to 8 mm, 8 mm to 8.5 mm, 8.5 mm to 9 mm, 9 mm to 9.5 mm, or 9.5 mm to 10 mm. In some instances, the spacing between components of a charged droplet management system can be as large as or greater than the diameter of the droplet, for example, where the spacing is greater than or approximately 100% of the droplet diameter, or even larger.Without restrictions, the spacing between components in charged droplet management is greater than or approximately 50%, 100%, 150%, 200%, 250%, 300%, 350%, 400%, 450%, 500%, 550%, 600%, 650%, 700%, 750%, 800%, 850%, 900%, 950%, 1000%, 1500%, 2000%, 3000%, 4000%, or 5000% of the droplet diameter, or greater.

[0067] To sense, detect, or characterize charged droplets using a charged droplet detector, a current is induced on the conductive layer of the detector when the charged droplet 149 or 249 passes through the aperture 109 or 209A. The magnitude of the induced current can be related to the distance between the charged droplet and the detector plate or its segment (e.g., ...). Figure 3 The segments 366A, 366B, 366C, and 366D shown are as follows: Figure 5 The relative positions of segments 566A, 566B, 566C, and 566D shown are associated. For example, a segment that generates a larger induced current may be relatively closer to droplet 149 than other segments, and by determining the difference between the induced currents of different segments, a weighting or scaling factor can be generated, which can be used to identify the two-dimensional position (e.g., XY) of droplet 149 as it passes through the aperture 109 and through the segments of the detector plate.

[0068] like Figure 2 As shown, the charged droplet 249 has a trajectory that causes it to deviate from axis 218 when it reaches aperture 155 (e.g., in the absence of the influence of charged droplet controller 209B), axis 218 representing the intended target position of charged droplet 249. The lateral deviation of the charged droplet from axis 218 at aperture 209A can be determined using charged droplet detector 210A, and this lateral deviation can be used to determine the voltage applied to the components of charged droplet controller 210B to generate an electric field at aperture 209B, which can deflect the trajectory of charged droplet 249 backward toward the target position at aperture 155.

[0069] Figure 3 An exploded view of the conductive layer of a charged droplet detector 310 according to at least some examples is shown. The charged droplet detector 310 may correspond to Figure 1 One embodiment of the charged droplet management device 110. The charged droplet detector 310 includes a first conductive layer 360, a second conductive layer 362, and a sensor layer 361. When a charged droplet 349 passes through the apertures of the charged droplet detector 310 (e.g., apertures including or including apertures 363, 364, and 365), at each segment of the sensor layer 361 (e.g., Figure 3An induced current is generated in segments 366A, 366B, 366C, and 366D. A spacer or insulating region 307 is located between segments 366A, 366B, 366C, and 366D to electrically isolate the segments from each other. The amount of induced current in each segment 366A, 366B, 366C, and 366D can depend on the lateral position of the charged droplet 349 as it passes through the aperture 364 and the relative dimensions of the segments. One or more circuit elements can be used to measure this induced current in each segment. For example, a transimpedance amplifier can be connected to each segment, and such a transimpedance amplifier can generate a measurable voltage output from each segment. As is known to those skilled in the art, by applying Ohm's law, this voltage output can be directly correlated with the induced current in the detector segment through the feedback resistance of the transimpedance amplifier. Therefore, this disclosure contemplates that the charged droplet detector or associated system can measure voltage, current, or any other measurement from which the induced current can be derived. While this disclosure considers the use of any suitable voltage / current / charge measurement circuit elements, an example of using a transimpedance amplifier to measure the output voltage is provided as an example.

[0070] If the segments are of equal size, a droplet passing precisely through the center of orifice 364 will induce equal currents in all four segments 366A, 366B, 366C, and 366D, and thus equal voltages at the corresponding outputs of the transimpedance amplifiers connected to these segments. As the droplet passes through the device, a droplet deviating from the center of the orifice, passing through a segment closer than another, will induce a larger current in the segment it passes through and a smaller current in the segment it passes through further away. These differences in the induced currents can be well simulated by those skilled in the art using, for example, the Ramo-Shockley theorem. Similarly, for unequal segments 366A, 366B, 366C, and 366D, the differences in induced currents can be well simulated by those skilled in the art by taking into account their size differences in the model. The lateral position of a droplet as it passes through the orifice 364 of the charged droplet detector 310 can be extracted by measuring the difference between the signals detected from each segment and appropriately normalizing or weighting them, for example, by the sum of signals from all sensors and / or by the peripheral portion of the orifice occupied by each segment, or by some more sophisticated method determined from the pattern. The total droplet charge, or a signal proportional to the total droplet charge, can be extracted from the sum of signals from all sensors, as measured using differential signaling, with minor corrections for any lateral misalignment of the droplet with the orifice center.

[0071] In some instances, this is achieved by measuring relative segments (e.g., segments relative along the X and / or Y axes, e.g., reference segments). Figure 3The difference in measured current between the signals detected relative to segments 366A and 366C, and relative to segments 366B and 366D, and appropriately normalized or weighted, for example, by the sum of signals from all segments of sensor layer 361 or by using weighting factors characterizing the peripheral portion occupied by each segment or characterizing other aspects or behaviors of the segments, can be used to extract the lateral (e.g., X, Y) position of the droplet as it passes through the aperture 364 of the charged droplet detector 310. In some cases, the droplet charge can also be extracted, for example, by using the sum of signals from all segments, as measured using differential signals, with minor corrections for any lateral misalignment of the droplet relative to the aperture center. The measurements of both the droplet's lateral position and the droplet charge are fundamental and may not require sensor calibration other than knowledge of its geometry and the current-voltage conversion characteristics of the transimpedance amplifier, although calibration may be used in some instances.

[0072] In some instances, additional sensor layers 361 may be stacked perpendicular to the travel axis of the droplet 349 to track the droplet as it passes through the aperture of the sensor device 310. While the examples described herein focus on determining or inferring the induced current by measuring the voltage from the transimpedance amplifier, this disclosure contemplates any suitable value from which the induced current can be determined.

[0073] Figure 4 A side view of a charged droplet detector 410 according to at least some examples is shown, which can be used with Figure 1 Charged droplet management device 110 Figure 2 Charged droplet detector 210A or Figure 3 The components of the charged droplet detector 310 may differ or be the same. The layers of the charged droplet detector 410 are shown, although additional layers may be implemented in some instances. In some instances, the charged droplet detector 410 may be or include a printed circuit board comprising a printed and / or screen-printed top layer 470 and solder mask layers 469 and 471. (See above reference...) Figure 3 The components of the charged droplet detector 310 are described, and within the printed circuit of the charged droplet detector 410 are conductive layers 460 and 462 and a sensor layer 461 (which is itself a conductive layer). Insulating layers 467 and 468 are located between the conductive layers 460 and 462 and the sensor layer 461 to electrically isolate the conductive layers 460 and 462 from the sensor layer 461. All layers define an aperture 409 through the charged droplet detector 410.

[0074] The insulating layers 467 and 468, the conductive layers 460 and 462, and the sensor layer 461 can each have any suitable thickness. For example, the insulating and / or conductive layers (including the sensor layer) in the charged droplet detector can have a thickness of 0.1 mm to 5 mm, such as 0.1 mm to 1.0 mm, or greater, such as 0.1 mm to 0.2 mm, 0.2 mm to 0.3 mm, 0.3 mm to 0.4 mm, 0.4 mm to 0.5 mm, 0.5 mm to 0.6 mm, 0.6 mm to 0.7 mm, 0.7 mm to 0.8 mm, or 0.8 mm to 0.9 mm. mm, 0.9mm to 1mm, 1mm to 1.1mm, 1.1mm to 1.2mm, 1.2mm to 1.3mm, 1.3mm to 1.4mm, 1.4mm to 1.5mm, 1.5mm to 1.6mm, 1.6mm to 1.7mm, 1.7mm to 1.8mm, 1.8mm to 1.9mm, 1.9mm to 2mm, 2mm to 2.1mm, 2.1mm to 2.2mm, 2.2mm to 2. 3mm, 2.3mm to 2.4mm, 2.4mm to 2.5mm, 2.5mm to 2.6mm, 2.6mm to 2.7mm, 2.7mm to 2.8mm, 2.8mm to 2.9mm, 2.9mm to 3mm, 3mm to 3.1mm, 3.1mm to 3.2mm, 3.2mm to 3.3mm, 3.3mm to 3.4mm, 3.4mm to 3.5mm, 3.5mm to 3.6mm, 3.6mm The thicknesses range from 3.7 mm to 3.8 mm, 3.8 mm to 3.9 mm, 3.9 mm to 4 mm, 4 mm to 4.1 mm, 4.1 mm to 4.2 mm, 4.2 mm to 4.3 mm, 4.3 mm to 4.4 mm, 4.4 mm to 4.5 mm, 4.5 mm to 4.6 mm, 4.6 mm to 4.7 mm, 4.7 mm to 4.8 mm, 4.8 mm to 4.9 mm, and 4.9 mm to 5 mm. In some cases, the thicknesses of the conductive and insulating layers can extend beyond these ranges, and in particular, the conductive layer can have a thickness of less than 0.2 mm or less than 0.1 mm. In some instances, the thickness of the conductive or insulating layer can be as large as or greater than the diameter of the droplet, for example, where the thickness is greater than or approximately 100% of the droplet diameter, or greater. Without restrictions, the thickness of the conductive or insulating layer is greater than or approximately 50%, 100%, 150%, 200%, 250%, 300%, 350%, 400%, 450%, 500%, 550%, 600%, 650%, 700%, 750%, 800%, 850%, 900%, 950%, 1000%, 1500%, 2000%, 3000%, 4000%, or 5000% of the droplet diameter, or greater. In some cases, the ratio of the aperture diameter to the thickness of one or more insulating layers can be from 0.25 to 4.In some cases, the ratio of the aperture diameter to the thickness of one or more conductive layers can be from 0.25 to 4. Optionally, the thickness of the conductive layers can be specified by manufacturing, for example, in the case of charged droplet management devices including printed circuit boards, where the thickness of the copper foil or copper plating can be standardized (e.g., copper layer thicknesses of about 35 μm, about 70 μm, about 105 μm, or about 140 μm). In some instances, the thickness of each insulating layer is the same, although optionally they can be different. In some instances, the thickness of each conductive layer, including the sensor layer, is the same, although optionally they can be different. In some instances, the thicknesses of the conductive layers and the insulating layers are different from each other, although they can be optionally the same.

[0075] although Figure 4 The detector shown in the diagram has a total of three electrodes and sensor layers, but in some instances, additional or fewer conductive layers and / or additional sensor layers may be included. In some instances, the layers including conductive layers 460 and 462 with sensor layer 461 and other layers may be arranged in a non-parallel manner, such that the layers are not arranged along a parallel plane, which can be used for three-dimensional detection of charged droplet positions. In some embodiments, sensor layer 461 with conductive layers 460 and 462 is or includes a metal, such as copper. Sensor layer 461 with conductive layers 460 and 462 can have any suitable lateral dimensions, such as 0.5 cm to 5 cm (e.g., 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, or 5 cm), although larger or smaller dimensions are possible. In some instances, sensor layer 461 or its components (e.g., segments of sensor layer 461) may have a larger lateral dimension than conductive layers 460 and 462 to provide an electrical connection to a transimpedance amplifier. For charged droplet sensing, conductive layers 460 and 462 may be electrically coupled to a reference potential, such as ground, while sensor layer 461 may be electrically coupled to a charge-sensitive circuit or a preamplifier, such as a transimpedance amplifier. The integrating circuitry of the transimpedance amplifier can be used to convert the induced current into a detectable voltage output. Insulating layers 467 and 468 may be formed of a suitable dielectric and / or insulating material, such as a laminate (e.g., as used in some printed circuit boards).

[0076] Figure 5 A charged droplet detector based on at least some examples is shown (e.g., Figure 1 The charged droplet detector of the charged droplet management device 110 Figure 2 Charged droplet detector 210A, Figure 3 Charged droplet detector 310 or Figure 4The image shows a top view of the sensor layer 561 of the charged droplet detector 410. In some embodiments, the sensor layer 561 defines an aperture 564, which may be at least a portion of the aperture 509 of the charged droplet detector 510 and may have a diameter of 2 mm. In some instances, the diameter may be greater than or less than 2 mm. Segments 566A, 566B, 566C, and 566D of the sensor layer 561 divide the layer into segments of equal size surrounding the aperture 564, each segment optionally providing an equal portion of the periphery of the aperture 564; however, this configuration is not intended to be limiting, and any suitable size or configuration of the segments may be used. Spacing or insulating regions 507 are located between segments 566A, 566B, 566C, and 566D to electrically isolate the segments from each other. As described below, each of segments 566A, 566B, 566C, and 566D is connected to a corresponding transimpedance amplifier 573A, 573B, 573C, and 573D to output a voltage proportional to the induced current in each of segments 566A, 566B, 566C, and 566D. In some instances, a single transimpedance amplifier or multiple transimpedance amplifiers may be used to determine the total charge on the droplet passing through orifice 564.

[0077] Figure 6 A cross-sectional view of a charged droplet detector 510, illustrating the electrical connections of a sensor layer according to at least some examples, is shown. The charged droplet detector 510 is shown as having... Figure 4 The described identical layers include three conductive layers 560, 561, and 562 separated by two insulating layers 567 and 568. In some embodiments, the total thickness of the charged droplet detector 510 is about 1 mm, although it may be greater or less than 1 mm. In some embodiments, these layers may each have a thickness of 200 micrometers (0.008 inches). In some embodiments, the total thickness may be about 2 mm. The charged droplet detector 510 may be mounted between the charged droplet source and the target, such that the droplet travels upward through the aperture 509. A bracket for positioning the detector XYZ above the charged droplet source and aligning the aperture 509 with the transducer shaft is not shown.

[0078] For droplet sensing, the two conductive layers 560 and 562, as well as any other layers (e.g., sensor layer 561), can be electrically coupled to or biased to a reference voltage (e.g., a high-voltage power supply), and each of segments 566A, 566B, 566C, and 566D of sensor layer 561 can be electrically coupled to a circuit element (e.g., a transimpedance amplifier) ​​for generating a signal (e.g., induced current or voltage). Each of conductive layers 560 and 562 and sensor layer 561 can optionally be biased to a high voltage to generate a charge on the droplet as it passes through aperture 564, for example, in the case of a droplet generator that does not generate a charged droplet. In some instances, the high voltage can also be applied at the target using a wire mesh or directly to the opening probe. As the droplet passes through aperture 564, the electric field generated by the voltage bias can exert a force on the charged droplet, potentially causing the droplet to accelerate, decelerate, and deflect its trajectory in an undesirable manner. Thus, a uniform electric field along the droplet trajectory is advantageous, such as a uniform electric field along the axis between the droplet generator and the target. In some instances, one or more of the conductive layers 560 and 562, or any other conductive layers, may be floated and / or at a reference (e.g., ground) voltage. Examples provided and described herein may include a fluid reservoir biased to a high potential when the charged droplet detector 510 is at a reference potential or ground potential. It will be understood that other implementations, such as biasing the charged droplet detector 510 to a high voltage to induce charge on the ejected droplet, may be used and are suitable for use with the systems and methods described herein.

[0079] In some instances, each segment 566A, 566B, 566C, and 566D can be associated with a transimpedance amplifier, which may optionally include one or more transimpedance amplifiers, although in Figure 6 Only one transimpedance amplifier, 573, is shown in the diagram. For Figure 5 The illustrated example shows four transimpedance amplifiers 573A, 573B, 573C, and 573D, each coupled to a corresponding segment of sensor layer 561. In some instances, sensor layer 561 may consist of any number of segments, each coupled to a corresponding transimpedance amplifier or other circuit element. In some embodiments, transimpedance unit 573 may include a Peltier-cooled input transistor with feedback components, such as 0.5 pF Cf and 1 gigahertz Rf. The integrating circuit of transimpedance unit 573 converts the current induced in the segment of sensor layer 561 by charged droplet 549 into a voltage output.

[0080] Figure 7 An exploded view of the layers of a charged droplet controller 710 according to at least some examples is shown. The charged droplet controller 710 may correspond to Figure 1One embodiment of the charged droplet management device 110. The charged droplet controller 710 includes a first conductive layer 760, a first support or insulating layer 761, a second conductive layer 762, and a second support or insulating layer 763. The conductive layers of the charged droplet controller (which may be segmented) may be referred to herein as conductive control layers. When a charged droplet 749 passes through the holes of the charged droplet controller 710 (e.g., holes including or comprising holes 764, 765, 766, and 767), an electric field can be applied between opposite segments in the conductive layers 760 or 762 (e.g., between segments 768A and 768B of the first conductive layer 760 and between segments 768C and 768D of the second conductive layer 762).

[0081] An electric field can be applied by maintaining each relative segment in the conductive layer at a different relative voltage. As shown, segments 768A and 768B of the first conductive layer 760 can generate an electric field along the X direction and cause the charged droplet 749 to deflect along the X direction, while segments 768C and 768D of the second conductive layer 762 can generate an electric field along the Y direction and cause the charged droplet 749 to deflect along the Y direction. Although segments 768A, 768B, 768C, and 768D... Figure 7 The segments are shown as residing in a separate conductive layer 762, but in some charged droplet controllers, the segments used to modify the trajectory of the charged droplet can all be located in the same plane or layer. Furthermore, although four segments are shown, any suitable number of segments can be used, and the voltage between the segments can be adjusted to generate a suitable electric field that modifies the trajectory of the charged droplet as it passes through the aperture. Additionally, although in Figure 7 Two support or insulating layers 761 and 763 are shown, but any suitable number of support or insulating layers can be used. For example, some configurations may not use any support or insulating layers (e.g., where the conductive layer provides its own support structure). Other instances may use only one support or insulating layer (e.g., where the entire segment of the conductive layer is in the same plane or layer and is supported by a single support or insulating layer).

[0082] Optionally, in addition to those used to regulate the trajectory of the charged droplet as it passes through the orifice, an additional conductive layer can be used in the charged droplet controller. In some instances, similar to Figure 3One or more grounded or reference conductive layers of the conductive layers 362 and 360 shown may be positioned above and / or below the main conductive layer including the segment and used to modify the trajectory of the charged droplet. Using such grounded or reference conductive layers can be used to limit the range of the electric field generated by the segmented conductive layers to extend significantly beyond the aperture. In some instances, all components of the charged droplet controller may be biased at a relative potential above or below ground and / or at a potential relative to the droplet generator or target. One or more voltage controllers or voltage generators may be used to control the voltage applied to each segment; these voltage controllers or voltage generators may be integrated as part of the charged droplet controller 710 or may be provided by external circuitry.

[0083] Despite the conductive layers 760 and 762 in Figure 7The image shows a flat surface, while the insulating layer 761 is shown as having a specific thickness, but any suitable thickness can be used. For example, the insulating and / or conductive layer in the charged droplet controller can have a thickness of 0.1 mm to 5 mm, such as 0.1 mm to 1.0 mm or greater, such as 0.1 mm to 0.2 mm, 0.2 mm to 0.3 mm, 0.3 mm to 0.4 mm, 0.4 mm to 0.5 mm, 0.5 mm to 0.6 mm, 0.6 mm to 0.7 mm, 0.7 mm to 0.8 mm, 0.8 mm to 0.9 mm, 0.9 mm... m to 1mm, 1mm to 1.1mm, 1.1mm to 1.2mm, 1.2mm to 1.3mm, 1.3mm to 1.4mm, 1.4mm to 1.5mm, 1.5mm to 1.6mm, 1.6mm to 1.7mm, 1.7mm to 1.8mm, 1.8mm to 1.9mm, 1.9mm to 2mm, 2mm to 2.1mm, 2.1mm to 2.2mm, 2.2mm to 2.3mm, 2 0.3mm to 2.4mm, 2.4mm to 2.5mm, 2.5mm to 2.6mm, 2.6mm to 2.7mm, 2.7mm to 2.8mm, 2.8mm to 2.9mm, 2.9mm to 3mm, 3mm to 3.1mm, 3.1mm to 3.2mm, 3.2mm to 3.3mm, 3.3mm to 3.4mm, 3.4mm to 3.5mm, 3.5mm to 3.6mm, 3.6mm The thicknesses are 3.7 mm to 3.8 mm, 3.8 mm to 3.9 mm, 3.9 mm to 4 mm, 4 mm to 4.1 mm, 4.1 mm to 4.2 mm, 4.2 mm to 4.3 mm, 4.3 mm to 4.4 mm, 4.4 mm to 4.5 mm, 4.5 mm to 4.6 mm, 4.6 mm to 4.7 mm, 4.7 mm to 4.8 mm, 4.8 mm to 4.9 mm, and 4.9 mm to 5 mm. In some cases, the thicknesses of the conductive and insulating layers can extend beyond these ranges, and in particular, the conductive layer can have a thickness of less than 0.2 mm or less than 0.1 mm. In some cases, the ratio of the aperture diameter to the thickness of one or more insulating layers can be from 0.25 to 4. In some cases, the ratio of the aperture diameter to the thickness of one or more conductive layers can be from 0.25 to 4. Optionally, the thickness of the conductive layer may be specified by manufacturing, for example in the case of a charged droplet management device including a printed circuit board, where the thickness of the copper foil or copper plating may be standardized (e.g., copper layer thickness of about 35 μm, about 70 μm, about 105 μm, or about 140 μm). In some instances, the thickness of each insulating layer is the same, although optionally they may be different. In some instances, the thickness of each conductive layer (if multiple conductive layers are present) is the same, although optionally they may be different. In some instances, the thicknesses of the conductive layers and the insulating layers are different from each other, although optionally they may be the same.In some instances, using a conductive layer thicker than 0.1 mm or 0.2 mm can impart stronger trajectory variations to charged droplets because a thicker conductive layer allows the charged droplet to interact with the electric field for a longer period. These cases can be considered as conductive layers with cylindrical holes, although in some instances they are segmented.

[0084] For example, the strength of the electric field generated between segments 768A and 768B of the first conductive layer 760 and segments 768C and 768D of the second conductive layer 762 can be determined by the relative voltage of each segment or the voltage difference between the relative segments. In some instances, although very high voltages can generate electric fields high enough to break up air and trigger electrostatic discharge, and this is to be avoided, any suitable voltage difference can be applied between the relative segments. In some instances, the relative voltage between different segments can be from 0V to 500V or higher, depending on the geometry of the segments. Exemplary relative voltages between different segments may be 0V to 25V, 0V to 50V, 0V to 75V, 0V to 100V, 0V to 125V, 0V to 150V, 0V to 175V, 0V to 200V, 0V to 225V, 0V to 250V, 0V to 275V, 0V to 300V, 0V to 325V, 0V to 350V, 0V to 375V, 0V to 400V, 0V to 425V, 0V to 450V, 0V to 475V, or 0V to 500V. It should be understood that the higher the voltage difference between segments, the stronger the electric field and the greater the trajectory adjustment.

[0085] Feedback mechanisms can be implemented in the systems, techniques, apparatuses, and methods described herein, for example, allowing the determination and selection of voltages applied to different segments of a charged droplet controller based on desired trajectory adjustments. For instance, by measuring the position of the charged droplet, such as using a charged droplet detector as described herein, and using fixed or known geometric parameters of the system and the target, the required voltages applied to different segments of the charged droplet controller can be determined. For example, assuming the orifice of the charged droplet detector and the charged droplet controller is aligned with the jet axis of the charged droplet generator and further aligned with the target, a droplet passing precisely at the center of the orifice of the charged droplet detector and the charged droplet controller will not require any trajectory adjustment, and thus the voltage applied to a segment of the charged droplet controller can be selected to generate a very small or zero electric field, such that no deflection of the trajectory will be applied. In another instance, a droplet deviating from the orifice center and passing through a segment closer than another segment will have a position identified by the charged droplet detector, allowing the determination and selection of an appropriate voltage applied to a segment of the charged droplet controller to modify the trajectory of the charged droplet so that it reaches the target on the axis. In some instances, lookup tables or fitted analytical solutions can be used to generate voltages to be applied to different segments of the charged droplet controller based on the determined position of the charged droplet at the charged droplet detector.

[0086] Figure 8 A side view of an charged droplet controller 810 according to at least some examples is shown, which can be used with... Figure 1 Charged droplet management device 110 Figure 2 210B charged droplet controller or Figure 7 The components of the charged droplet controller 710 may differ or be the same. The layers of the charged droplet controller 810 are shown, although additional layers may be implemented in some instances. In some instances, the charged droplet controller 810 may be or include a printed circuit board comprising a printed and / or screen-printed top layer 870 and solder mask layers 869 and 871. (See above reference...) Figure 7 As described in the components of the charged droplet controller 710, conductive layers 860 and 862 are present within the printed circuitry of the charged droplet controller 810. Insulating layers 861 and 863 are located between conductive layers 860 and 862 to support conductive layers 860 and 862 and / or to electrically insulate conductive layers 860 and 862 from each other. All layers define an aperture 809 through the charged droplet detector 810. In some instances, insulating layers 861 and 863 may have a thickness between 0.1 mm and 1.0 mm. Although Figure 8 The charged droplet controller 810 shown in the diagram has a total of two conductive layers and a total of two insulating layers, but in other instances, more or fewer conductive and / or insulating layers may be included. In some instances, the layers including conductive layers 860 and 862 and insulating layers 861 and 863, as well as any other layers, may be arranged in a non-parallel manner, such that these layers are not arranged along a parallel plane. In some embodiments, for example, conductive layers 860 and 862 are, for example, copper or gold. Conductive layers 860 and 862 may have any suitable lateral dimensions, such as 0.5 cm to 5 cm (e.g., 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, or 5 cm), although larger or smaller dimensions are possible. In some instances, conductive layers 860 and 862, or components thereof (e.g., segments of conductive layers 860 and 862), may have a larger lateral dimension than insulating layers 861 and 863 to provide electrical connections to one or more voltage controllers. Insulating layers 861 and 863 may be formed of suitable dielectric and / or insulating materials, such as laminates (e.g., as used in some printed circuit boards).

[0087] Figure 9 A top view of the conductive layer 960 of a charged droplet controller 910 according to at least some examples is shown, which can be connected with... Figure 1 The charged droplet controller of the charged droplet management device 110 Figure 2210B charged droplet controller Figure 7 710 charged droplet controller or Figure 8 The charged droplet controller 810 may be the same as or different from the charged droplet controller 910. In some embodiments, the conductive layer 960 defines an aperture 965, which may be at least a portion of the aperture 909 of the charged droplet controller 910 and may have a diameter of 2 mm. In some instances, the diameter may be greater than or less than 2 mm. Segments 968A, 968B, 968C, and 968D of the conductive layer 960 divide the layer into segments of equal size surrounding the aperture 965, each segment optionally providing an equal portion of the periphery of the aperture 965. Spacers or insulating regions 907 are located between segments 968A, 968B, 968C, and 968D to electrically isolate the segments from each other. Each of segments 968A, 968B, 968C, and 968D is connected to a corresponding voltage controller 974A, 974B, 974C, and 974D, as described below, to generate an electric field of desired or predetermined size and orientation at orifice 965, thereby modifying the trajectory of charged droplet 949 as it passes through orifice 965. In some instances, a single voltage controller or multiple voltage controllers may be used to apply voltage between different segments of conductive layer 960. Optionally, a single voltage controller may be connected between opposite segments to set a voltage difference between opposite segments. For example, voltage controllers 974A and 974C may be the same voltage controller that sets the voltage difference between segments 968A and 968C, or voltage controllers 974B and 974D may be the same voltage controller that sets the voltage difference between segments 968B and 968D. In some instances, each segment 968A, 968B, 968C, and 968D may be associated with a voltage controller, although in Figure 10 Only one voltage controller 974 is shown, but the voltage controller may optionally include one or more voltage controllers. For Figure 9 The example shown illustrates four transimpedance amplifiers 974A, 974B, 974C, and 974D, each coupled to a corresponding segment of conductive layer 960.

[0088] Figure 10 A cross-sectional view of a charged droplet controller 910, illustrating electrical connections of a conductive layer according to at least some examples, is shown. The charged droplet controller 910 is shown having... Figure 8The described layers, in varying numbers and configurations, include a conductive layer 960 and an insulating layer 961. In some embodiments, the total thickness of the charged droplet controller 910 is approximately 0.4 mm, although it may be greater or less than 0.4 mm. In some embodiments, these layers may each have a thickness of 200 micrometers (0.008 inches). In some embodiments, the total thickness may be approximately 0.8 mm. The charged droplet controller 910 may be mounted between the charged droplet source and the target, such that the droplet travels upward through the aperture 909. A bracket for positioning the controller XYZ above the charged droplet source and aligning the aperture 909 with the transducer shaft is not shown.

[0089] For droplet control, the voltage difference applied between relative segments 968A and 968C can be used to regulate the deflection of the charged droplet in the Y direction, and the voltage difference applied between relative segments 968B and 968D can be used to regulate the deflection of the charged droplet in the X direction. The voltage applied to the segments of conductive layer 960 can be biased above or below ground potential to establish a total floating potential to the charged droplet controller 910, which can be used to accelerate, decelerate, or maintain the relative velocity of the charged droplet approaching or leaving the charged droplet controller 910. As the droplet passes through the aperture 965, the electric field generated by the voltages applied to the different segments can exert a force on the charged droplet, causing the trajectory of the charged droplet 949 to accelerate, decelerate, and deflect in a controlled manner.

[0090] Figure 11 , Figure 12 and Figure 13 A graph is shown illustrating the values ​​of the induced current in different segments as a charged droplet passes through the aperture of a charged droplet detector. Figure 11 The differential current flowing through the relative segments is shown, and will be explained in further detail below. Figure 12 Figure 1279, illustrating at least some examples, shows the current from a segment of the sensor layer of a charged droplet detector caused by a charged droplet passing through an orifice in the detector over time. Each of the datasets 1282, 1281, and 1280 shown represents the current measured in the segment as a charged droplet is ejected from a fluid reservoir toward a target location through the orifice. As shown, datasets 1282, 1281, and 1280 represent the current in the segment at different lateral offsets of the charged droplet from the segment of the sensor layer. For example, dataset 1280 could represent a droplet passing through the center of the orifice, while dataset 1282 is laterally offset closer to the sensor layer segment, and dataset 1281 is laterally offset away from the segment on the opposite side of the orifice from the position associated with dataset 1282. As shown, a larger current, as in dataset 1282, indicates a charged droplet positioned closer to the segment compared to a smaller current, such as that shown in dataset 1281. Figure 12On the left, each of datasets 1280, 1281, and 1282 shows the initial induced current at t0, indicating that there is no charged droplet in the orifice. As the droplet passes through the sensor layer of the charged droplet detector at t1, the current represented by datasets 1280, 1281, and 1282 reverses through the initial reference and as the direction of the induced current reverses, until t2 when the droplet leaves the orifice. Similarly, in Figure 13 The diagram shows the output voltages from four transimpedance amplifiers, with amplitudes varying based on the time-varying current values ​​of the segments as the droplet passes through the aperture of the charged droplet detector. For example, in... Figure 13 The measured voltages depicted in Figure 1383 indicate that the corresponding droplets passing through the charged droplet detector are closer to the segments associated with datasets 1385 and 1386 than the segments associated with datasets 1384 and 1387 (as evidenced by the larger voltage fluctuations).

[0091] Figure 11 Graph 1174, illustrated according to at least some examples, shows the differential current from relative segments of the sensor layer of a charged droplet detector for different charged droplet displacement positions along the axis between the droplet source and the target destination. In Graph 1174, when measuring the signal, the horizontal axis is time, which can be correlated with the vertical position (Z position) of the charged droplet, while the differential current is shown on the vertical axis. Different datasets representing different signals are shown on Graph 1174, corresponding to the differences in measured current between relative segments located on opposite sides of the aperture when the charged droplet passes through the aperture.

[0092] The first dataset 1175 in the chart shows relative segments (e.g.) Figure 3 Segments 366B and 366D or Figure 5 The output voltage difference between segments 566B and 566D, where the droplet trajectory is vertical but laterally offset from the center of the orifice toward one of the segments. Figure 3 Segments 366A and 366C or Figure 5 The corresponding set of curves for the difference in measured current between segments 566A and 566C will additionally produce information about the droplet's movement along a second direction (e.g., reference) as it passes through the orifice and is relative to the orifice center. Figure 5 Information about the position of the droplet (along the Y-axis shown). If the droplet is in two directions (e.g., along the Y-axis), Figure 5If the droplet passes through the center of the aperture in the X and Y directions (as shown), then all differential curves will be substantially flat, indicating a 0V output. The output from each segment can be weighted or normalized relative to the sum of the currents through all segments (essentially normalizing the droplet charge from the differential measurement), or using a weighting factor representing the area of ​​the segment or a portion of the perimeter of the aperture occupied by the segment. In some instances, the output can be normalized by dividing each output by the sum of all outputs from each sensor. In some instances, the sum signal from all segments has the shape of a bipolar pulse due to the droplet passing through the device. The magnitude of this sum signal can be used as an appropriate normalization factor for the differential current. The polarity of the droplet charge can be extracted by recording the phase of the bipolar pulse obtained from the summation of the sensor signals. The second dataset 1176 shows the difference in measured current between segments having a droplet trajectory offset by a first amount from the central axis of the aperture toward the second segment in the opposite direction to the first dataset 1175. The third dataset 1177 shows the difference in measured current between segments having a droplet trajectory offset by a first amount from the central axis of the aperture toward the second segment in the opposite direction to the first dataset 1175. Figure 5 The difference in measured current between segments of a droplet offset by a second amount towards the first segment (shown on the X-axis) is smaller than the first amount, resulting in a smaller difference in measured current between the relative segments. The fourth dataset 1178 of Figure 1174 shows the difference in measured current between segments of a droplet offset by a second amount towards the second segment in the opposite direction to the third dataset 1177. As described above, when normalized using the summation sensor signal and knowledge of the droplet charge polarity also obtained from the summation sensor signal, the differential current from the segments can be used to determine the droplet trajectory along the first direction (e.g., along...). Figure 3 and Figure 5 The lateral offset (shown on the X-axis). Similar analysis of the differential current from additional segments (e.g., vertical segments) can allow determination along the X-axis. Figure 3 and Figure 5 Lateral offset of the droplet trajectory along the Y-axis. Lateral offsets along the X and Y axes can be used to generate weighted sums that identify droplet positions, such as weighted plots of droplet positions corresponding to the relative positions of the droplets weighted by the current from the relative segments.

[0093] Output voltage and / or differential current can be used to identify the position and velocity of a charged droplet. In some instances, the sum of all output voltages or currents can be used to determine the droplet charge and droplet velocity (e.g., using...). Figure 14The sum of 1494). In Figure 1174, when measuring the signal, the horizontal axis is time, which can be correlated with the vertical position (Z position) of the charged droplet, while the differential current is shown on the vertical axis. For example, the velocity can be determined based on the time it takes for the droplet to pass through the detector. Since the droplet passes through the device at a substantially constant velocity, the positions shown in Figures 1174 and 1279 are correlated with the droplet velocity and time. In Figures 1174 and 1279, each curve has three distinct characteristics: a peak, a minimum, and a zero crossover that occurs roughly in the middle between the peak and the minimum. The corresponding time associated with each of these characteristics is: T peak T min and T zerocrossing The time it takes to emit acoustic energy onto the fluid surface to generate droplets can be set as T0. The droplets at T... zerocrossing The current is zero at the moment the droplet reaches the minimum distance to each segment, located in the plane of the sensor layer. Given the height of the sensor layer above the fluid in the orifice (which is typically the case), this height is called H. sensor Then, a measured value of the droplet velocity is determined using the following equation: H sensor / (T zerocrossing -T0). Given the height of the sensor layer above the fluid surface, this equation produces the velocity based on the time it takes for a droplet to travel from the fluid surface to the sensor layer.

[0094] In some instances, it can be based on T peak and T min The difference between the droplet velocity and the conductive layer (e.g., ...) is used to measure the droplet velocity. Figure 3 The distance between conductive layers 362 and 360 in the diagram is related and referred to as distance d in this paper. For example, for the conductive layer geometry, time T peak -T min =0.71*d / v droplet , where v droplet This is the "instantaneous" velocity of the droplet as it passes through the sensor layer. Therefore, the instantaneous velocity can be determined as v. droplet =0.71*d / |T peak -T min The coefficient 0.71 comes from the modeling of the device, but is strictly attributed to its geometry and is independent of droplet charge, volume, and other factors; therefore, other coefficients may be used for other geometries.

[0095] Figure 14 Figure 1488 shows output voltage signals 1489, 1490, 1491, and 1492, and the sum of all output voltage signals 1494 received from the transimpedance amplifiers associated with the four segments of the sensor layer, for example, the above regarding Figure 5As shown and described herein, according to at least some examples, the output voltage signal can be used to determine the position 1496 of a droplet traveling through an aperture in a sensor device. Using the output signal of Figure 1488 and performing the calculations described herein, the inferred XY position 1496 of the droplet is determined and is shown in Figure 1488. Figure 15 In the middle, the inferred XY position 1496 of the droplet corresponds to the predicted position of the droplet passing through the orifice (predicted using the output signal described herein), while the stage position XY position 1495 represents the transducer axis defined by the position of the stage where the transducer is placed, for example... Figure 1 The transducer axis 118. That is, assuming the droplet trajectory is aligned along the axis of the acoustic transducer, the stage position XY position 1495 is the expected position where the droplet passes through the aperture. Figure 15 As shown, the inferred XY position 1496 coincides with the stage position XY position 1495, thus verifying the use of induced current to predict droplet position as described herein. As mentioned above, the position can be determined using the induced current within the segment of the sensor layer based on the relative magnitudes of the peak values ​​of the output voltage signals 1489, 1490, 1491, and 1492.

[0096] Figure 16 A diagram 1600, illustrating at least some examples, provides output voltage signals 1601, 1602, 1603, and 1604 corresponding to the main droplet 1608 and satellite droplets 1606 traveling through the orifice, and a sum 1609 of all output voltage signals. The satellite droplet 1606 can be an undesirable secondary droplet that can be ejected from the fluid during a given ejection period, and secondary droplets may be generated if the device is not properly regulated or if excessive power is applied when generating the main droplet 1608. Figure 16 The diagram shows the resulting signals from the sensor layer as the output of a transimpedance amplifier, and... Figure 17 The diagram shows the inferred XY positions of the main droplet 1608 and satellite droplet 1606, as well as the stage position 1607. The positions of the main droplet 1608 and satellite droplet 1606 are determined based on the induced current of a segment of the sensor layer shown, which identifies peak values ​​indicating the positions of the main droplet 1608 and satellite droplet 1606. The position of the satellite droplet 1606 can be determined based on relative amplitude, for example, to distinguish the main droplet 1608 and satellite droplet 1606. For example, in... Figure 16In this configuration, satellite droplet 1606 is identifiable at T2, while the main droplet 1608 is at T1, and can be clearly identified based on differences in the peaks of the dataset representing the sum 1609. In some embodiments, the identification of the satellite droplet can be used to determine whether adjustment of injection parameters (e.g., transducer parameters) is necessary. For example, one approach may include determining, based on measurements corresponding to values ​​of induced currents as described herein, that a satellite droplet has been ejected in a particular injection. Based on this determination, it can be determined that adjustment of transducer parameters is needed to prevent further ejection of the satellite droplet. Therefore, the transducer parameters can be adjusted for the next injection (e.g., by reducing the amplitude or frequency of the acoustic signal). These steps can be repeated frequently as needed to provide iterative fine-tuning of the injection and prevent or at least reduce the ejection of the satellite droplet.

[0097] Figure 18 A flowchart illustrating a process for detecting charged droplets from a droplet generator, based on at least some examples, is shown. Any suitable computing system or group of computing systems can be used to perform aspects of the methods described herein. For example, Figure 25 An example of a computing device 2500 is described, which may be at least part of a computing system that performs the operations or methods described herein.

[0098] At box 1802, method 1800 includes positioning a charged droplet detector between the droplet generator and the target, for example... Figure 1 and Figure 2 As shown. Based on at least some instances, the detector can be Figure 1 Charged droplet management device 110 Figure 2 The 210A charged droplet detector Figure 3 Charged droplet detector 310 Figure 4 Charged droplet detector 410 or Figure 6 The charged droplet detector 510 is an assembly of the charged droplet detector. The charged droplet detector can be positioned such that the orifice is aligned with the jet axis of the droplet generator (e.g., aligned with the transducer axis of an acoustic droplet jet system).

[0099] At box 1804, method 1800 includes guiding a charged droplet from a droplet generator to a target through an aperture of a charged droplet detector. For example, the charged droplet may be generated by, as per [the relevant information] Figure 1 The droplet generator described is used for propulsion.

[0100] At block 1806, method 1800 includes analyzing a voltage signal generated by a charged droplet detector to determine the droplet's position and / or velocity. The voltage signal may be output from a transimpedance amplifier connected to a corresponding segment of the sensor layer. The voltage signal may correspond to the induced current in each segment as a result of the charged droplet passing through the aperture. As described herein, the droplet's position can be determined based on a weighted average of the voltage signals from the segments of the sensor layer.

[0101] Figure 19 A top view of a conductive layer 1960 of a charged droplet controller according to at least some examples is shown. The conductive layer 1960 is compatible with... Figure 1 The charged droplet detector of the charged droplet management device 110 Figure 2 210B charged droplet controller Figure 7 710 charged droplet controller Figure 8 810 charged droplet controller or Figure 8 The charged droplet controller 810 may be the same as or different from it. Figure 19 In the diagram, voltages V1, V2, V3, and V4 are shown as segments 1968A, 1968B, 1968C, and 1968D of conductive layer 1960, respectively.

[0102] Figure 20 , Figure 21 and Figure 22 The relative positions of the charged droplets at the first Z position (+) and the second Z position (O) are shown, for example, as measured by two charged droplet detectors on opposite sides of the charged droplet controller, wherein a voltage is applied to, as Figure 19 The sections 1968A, 1968B, 1968C, and 1968D of the charged droplet controller. Figure 20 , Figure 21 and Figure 22 In the process, the first Z position 2095(+) of the charged droplet is determined to be offset from the center 2019 of the hole along both the X and Y directions.

[0103] Figure 20 A configuration is shown in which the voltage difference applied between segments 1968A and 1968C is zero (V1-V3 = 0V), and the voltage difference applied between segments 1968B and 1968D is zero (V2-V4 = 0V), indicating that the charged droplet controller is not deflecting the charged droplet. The second Z position 2096(O) of the charged droplet is... Figure 20 The image also shows a deviation from the center in 2019.

[0104] Figure 21A configuration is shown in which the voltage difference applied between segments 1968A and 1968C is zero (V1 - V3 = 0V), but the voltage difference applied between segments 1968B and 1968D is 200V (V2 - V4 = 200V), indicating that the charged droplet controller deflects the charged droplet in the X direction but not in the Y direction. The second Z position 2097(O) of the charged droplet is... Figure 21 The image shows a continued deviation from the center in 2019, but in the X direction it is more... Figure 20 The smaller deviation indicates that the adjustment of the charged droplet trajectory applied by the charged droplet controller provides some correction to the trajectory, but further correction could make additional improvements.

[0105] Figure 22 A configuration is shown in which a voltage difference of 400V (V1 - V3 = 400V) is applied between segments 1968A and 1968C, and a voltage difference of 400V (V2 - V4 = 400V) is applied between segments 1968B and 1968D. This indicates that the droplet controller deflects the charged droplet along the X and Y directions to a greater extent than... Figure 21 The X-direction deflection is greater in this case. Under this voltage condition, the position 2098(O) of the charged droplet on the substrate is... Figure 22 The image shown is corrected to be very close to the center in 2019. It should be understood that the correction applied to the above is for... Figure 20 , Figure 21 and Figure 22 The voltages of the various segments mentioned are merely examples and are not intended to be limiting. Any suitable voltage or voltage difference can be used to regulate the trajectory of the charged droplet, and such voltage or voltage difference can be determined by the geometry of the system, the position and / or velocity and / or desired changes (including amplitude and direction) of the charged droplet.

[0106] Figure 23 A flowchart illustrating, based on at least some examples, a process for controlling the ejection of charged droplets from a droplet generator is shown. Any suitable computing system or group of computing systems can be used to perform aspects of the methods described herein. For example, Figure 25 An example of a computing device 2500 is described, which may be at least part of a computing system that performs the operations or methods described herein.

[0107] At box 2302, method 2300 includes positioning a charged droplet controller between the droplet generator and the target, for example... Figure 1 and Figure 2 As shown. According to at least some examples, a charged droplet controller can be... Figure 1 Charged droplet management device 110 Figure 2 210B charged droplet controller Figure 7710 charged droplet controller Figure 8 810 charged droplet controller or Figure 10 The charged droplet controller 910 is an assembly of the charged droplet controller. The charged droplet controller can be positioned such that the orifice is aligned with the jet axis of the droplet generator (e.g., aligned with the transducer axis of an acoustic droplet jetting system).

[0108] At box 2304, method 2300 includes guiding a charged droplet from a droplet generator to a target through an aperture of a charged droplet controller. (See also: Regarding...) Figure 1 The charged droplets can be propelled by a droplet generator.

[0109] At block 2306, method 2300 includes determining and applying a voltage to a segment of one or more conductive layers of a charged droplet controller to modify the droplet's trajectory. For example, the voltage may be generated automatically or by using feedback from the velocity or position of the charged droplet determined by a charged droplet detector. In other instances, the voltage may be determined and applied empirically, for example, by controlling the trajectory of additional droplets through user input to adjust or optimize the droplet trajectory to achieve or improve arrival at a target.

[0110] Figure 24 A flowchart illustrating a process for detecting and controlling charged droplets ejected from a droplet generator using a feedback scheme, based on at least some examples, is shown. Any suitable computing system or group of computing systems can be used to perform aspects of the methods described herein. For example, Figure 25 An example of a computing device 2500 is described, which may be at least part of a computing system that performs the operations or methods described herein.

[0111] At box 2402, method 2400 includes positioning a charged droplet detector between the droplet generator and the charged droplet controller, for example... Figure 2 As shown. Based on at least some examples, a charged droplet detector can be... Figure 1 Charged droplet management device 110 Figure 2 Charged droplet detector 210A, Figure 3 Charged droplet detector 310 Figure 4 Charged droplet detector 410 or Figure 6 The charged droplet detector 510 is a component of the charged droplet detector. According to at least some examples, the charged droplet controller can be... Figure 1 Charged droplet management device 110 Figure 2 210B charged droplet controller Figure 7 710 charged droplet controller Figure 8 810 charged droplet controller or Figure 10The charged droplet controller 910 is an assembly. The charged droplet detector and the charged droplet controller can be positioned such that the apertures are aligned with each other and / or aligned with the jet axis of the droplet generator (e.g., aligned with the transducer axis of an acoustic droplet jetting system).

[0112] At box 2404, method 2400 includes guiding a charged droplet from a droplet generator toward an aperture passing through a charged droplet detector and a charged droplet controller. (See also...) Figure 1 The charged droplets can be propelled by a droplet generator.

[0113] At block 2406, method 2400 includes analyzing a voltage signal generated by the charged droplet detector to determine the position and / or velocity of the droplet. The voltage signal may be output from transimpedance amplifiers of respective segments of a sensor layer connected to the charged droplet detector. The voltage signal may correspond to the induced current of each segment as a result of the charged droplet passing through an aperture. As described herein, the position of the droplet can be determined based on a weighted average of the voltage signals from the segments of the sensor layer. In some instances, the voltage waveform from the transimpedance amplifier may be analyzed by a signal processing component to extract the position and / or velocity of the charged droplet at the charged droplet detector.

[0114] At block 2410, method 2400 includes determining and applying a voltage to segments of one or more conductive layers of a charged droplet controller to modify the trajectory of the droplet. The voltage is determined using the velocity or position of the charged droplet from a signal processing component, and may be determined, for example, using a lookup table or analysis function, where one or more coordinates of the charged droplet (e.g., X and Y) are considered as inputs, and the voltage applied to the segment (or the voltage difference applied to segments opposite each other) is determined as the output applied to the segment of the conductive layer.

[0115] Figure 25 A block diagram illustrating an example of computing device 2500 is shown. Computing device 2500 can be any computer described herein, including computing devices that perform method 1800 and receive signals from one or more transimpedance amplifiers, such as method 2300, method 2400, other methods described herein, or aspects or portions of such methods. Computing device 2500 can be or includes, for example, an integrated computer, a laptop computer, a desktop computer, a tablet computer, a server, or other electronic equipment.

[0116] Computing device 2500 may include a processor 2540 that interfaces with other hardware via bus 2505. Memory 2510, which may include any suitable tangible (and non-transitory) computer-readable medium such as RAM, ROM, EEPROM, etc., may embody program components (e.g., program code 2515) configuring the operation of computing device 2500. Memory 2510 may store program code 2515, program data 2517, or both. In some instances, computing device 2500 may include input / output (“I / O”) interface components 2525 (e.g., for interfacing with a display 2545, keyboard, mouse, etc.) and additional storage 2530.

[0117] Computing device 2500 executes program code 2515, which configures processor 2540 to perform one or more operations described herein. Among various instances, examples of program code 2515 include those described above. Figure 18 , 23 The logic flowchart described in section 24. Program code 2515 may reside in memory 2510 or any suitable computer-readable medium and may be executed by processor 2540 or any other suitable processor.

[0118] The computing device 2500 can generate or receive program data 2517 by executing program code 2515. For example, sensor data, travel counters, authentication messages, travel flags, and other data described herein are examples of program data 2517 that can be used by the computing device 2500 during the execution of program code 2515.

[0119] Computing device 2500 may include network component 2520. Network component 2520 may represent one or more of any components that facilitate network connectivity. In some instances, network component 2520 may facilitate wireless connectivity and includes technologies such as IEEE 802.11, BlueTouch, etc. TM The wireless interface, or a wireless interface for accessing cellular telephone networks (e.g., a transceiver / antenna for accessing CDMA, GSM, UMTS, or other mobile communication networks). In other instances, network component 2520 may be wired and may include interfaces such as Ethernet, USB, or IEEE 1394.

[0120] Although Figure 25 A computing device 2500 with a processor 2540 is depicted, but the system may include any number of computing devices and any number of processors. For example, multiple computing devices or multiple processors may be distributed across wired or wireless networks (e.g., wide area networks, local area networks, or the Internet). Multiple computing devices or multiple processors may perform any steps of this disclosure individually or collaboratively.

[0121] Aspects of the invention can be further understood by referring to the following non-limiting embodiments. Embodiment 1: Charged droplet ejection, detection, and control system

[0122] Figure 26 An overview of an embodiment of an charged droplet ejection, detection, and control system 2600, based on several examples, is provided. System 2600 may include components described elsewhere in this disclosure, including one or more droplet generators (e.g., regarding...). Figure 1 and Figure 2 The described droplet generator 101), and one or more charged droplet management devices (e.g. Figure 1 Charged droplet management device 110), one or more charged droplet detectors (e.g., charged droplet management device 110), and one or more charged droplet detectors (e.g., charged droplet detectors). Figure 2 Charged droplet detector 210A, Figure 3 Charged droplet detector 310 Figure 4 Charged droplet detector 410 or Figure 6 Charged droplet detector 510), or one or more charged droplet controllers (e.g., Figure 2 210B charged droplet controller Figure 7 710 charged droplet controller Figure 8 810 charged droplet controller or Figure 10 The charged droplet controller 910 and one or more computing devices (e.g., computing device 2500).

[0123] like Figure 26 As shown, system 2600 includes a charged droplet control and detection system 2605. The charged droplet control and detection system 2605 may include physical hardware, such as a droplet generator and a charged droplet management device. (As mentioned above...) Figure 1 The droplet generator of the charged droplet control and detection system may include an acoustic droplet ejection system that uses tone burst excitation 2610 to drive the acoustic generator to eject droplets.

[0124] The charged droplet control and detection system 2605 can communicate with and / or control the data collection system 2615, which may include one or more computing devices according to the examples described herein. As shown, a digital signal associated with the tone burst excitation 2610 can be transmitted to an external interrupt 2620 of the data collection system 2615, which may allow the data collection system 2615 to determine the timing of droplet generation by the charged droplet control and detection system 2605.

[0125] As described above, the charged droplet detector of the charged droplet control system generates a voltage representing the proximity of the ejected charged droplet to a segment of the sensor layer, and the droplet voltage detection and control 2625 transmits this voltage to the voltage control and collection system 2630. Specifically, the voltage can be transmitted to the voltage amplification circuit 2635, which then sends the amplified voltage to the analog-to-digital converter 2640 to convert the voltage into a digital signal for transmission to the data collection system 2615.

[0126] At the data acquisition system 2615, a digital signal representing voltage can be received at an analog-to-digital (ADC) interrupt 2645 or other digital input system. The ADC interrupt 2645 can extract raw ADC data and transmit it to a timer interrupt 2650 and / or a computing system 2655. The computing system 2655 can analyze the raw ADC data to generate position data of the charged droplet at the charged droplet detector. For example, the timer interrupt 2650 can use information from an external interrupt 2620 to determine timing information for detecting the charged droplet. The computing system 2655 can use this timing information and position data to determine the velocity or trajectory of the charged droplet. The raw ADC data and position data can be transmitted to a local storage buffer 2660 to locally cache and / or store the data within the data acquisition system 2615. The Controller Area Network (CAN) bus 2665 or other input / output system can receive position data and / or raw ADC data from the local storage buffer 2660 or computing system 2655 and transmit the information to the user computing device 2670, for example, by an Inductively Charged Droplet Detection (ICDD) application 2675 running thereon.

[0127] For droplet trajectory control, computing system 2655 can analyze position data and determine voltage groups suitable for application to the control layer of the charged droplet controller in charged droplet control and detection system 2605. For example, the voltage can be transmitted digitally to voltage control and collection system 2630, where digital-to-analog converter 2680 can generate a voltage that is transmitted to droplet voltage detection and control 2625 to modify the droplet trajectory.

[0128] The subject matter of this invention is specifically described herein to satisfy legal requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future techniques. Unless the order of the steps or the arrangement of the elements is explicitly described, this specification should not be construed as implying any particular order or arrangement of the steps or elements in or between.

[0129] For clarity, not all the conventional features of the examples described herein have been shown and described. Of course, it should be understood that in the development of any such actual implementation, many implementation-specific decisions need to be made to achieve the developer’s specific goals, such as complying with application and business-related constraints, and these specific goals will change from one implementation to another and from one developer to another.

[0130] While the invention has been described in detail with respect to specific aspects thereof, it should be understood that changes, variations, and equivalents of these aspects can be readily made by those skilled in the art upon understanding the foregoing. Numerous specific details have been set forth herein to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without these specific details. In other instances, methods, apparatus, or systems known to those of ordinary skill in the art have not been described in detail so as not to obscure the claimed subject matter. Therefore, this disclosure has been presented for purposes of example rather than limitation, and this disclosure does not exclude the inclusion of such modifications, variations, and / or additions to the subject matter that are obvious to those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and systems of the invention without departing from the spirit or scope of the invention. Therefore, the invention is intended to include modifications and variations within the scope of the appended claims and their equivalents. It should be understood that any usable combination of the features and capabilities disclosed herein is also considered disclosed.

Claims

1. An apparatus for detecting or controlling charged droplets from a charged droplet generator, the apparatus comprising: A sensor element having three or more conductive layers separated by an insulating layer, the conductive layers and the insulating layer defining an aperture through which a charged droplet of the sensor element passes, wherein the inner layer of the three or more conductive layers is a segmented conductive layer having multiple separate segments that are electrically independent of each other and arranged around the periphery of the aperture at the segmented conductive layer. A circuit element electrically coupled to each of the separate segments, wherein each of the plurality of separate segments is positioned to provide an induced current to the circuit element when a charged droplet passes through the aperture, and the circuit element is configured to generate a signal proportional to the induced current. as well as A computing device is used to determine the velocity of the charged droplet using the following formula: H sensor / (T zerocrossing - T0), where H sensor is the height of the segmented conductive layer above the fluid surface of the reservoir well of the charged droplet generator, T zerocrossing is the time at which the induced current is zero when the charged droplet reaches a minimum distance from each separate segment, and To is the time at which acoustic energy is emitted toward the fluid surface to produce the charged droplet.

2. The apparatus of claim 1, wherein, Each of the plurality of separate segments is located at a corresponding portion of the periphery of the hole.

3. The apparatus of claim 1, wherein, Each of the plurality of separate segments occupies a peripheral portion of the hole equal to one or more other separate segments.

4. The apparatus of claim 1, wherein, The plurality of separate segments include at least two pairs of separate segments, wherein the separate segments in one pair of separate segments are arranged opposite each other around the hole.

5. The apparatus of claim 1, wherein, The sensor element is positioned between the source and the target destination of the charged droplet generator.

6. The apparatus of claim 1, wherein, The outer conductive layer of the three or more conductive layers is maintained at ground potential or reference potential.

7. The apparatus of claim 1, wherein, The circuit elements include a transimpedance amplifier.

8. The apparatus of claim 1, wherein, The computing device includes: Processor; and A non-transitory computer-readable storage medium that communicates with the processor, the non-transitory computer-readable storage medium storing processor-executable instructions that, when executed by the processor, cause the processor to perform operations including: Receive signals from the circuit elements, and The position of the charged droplet is determined based on the signal.

9. The apparatus of claim 8, wherein, Determining the position of the charged droplet includes: Each signal from the plurality of separate segments is weighted to determine a normalized signal; and The position of the charged droplet is determined based on the amplitude of the normalized signal.

10. The apparatus of claim 8, wherein, The operation further includes determining one or more of the following: The time it takes for the charged droplet to reach the orifice; and The charge-to-volume ratio of the charged droplets; or the presence of one or more charged satellite droplets.

11. The apparatus of claim 1, wherein, The signal proportional to the induced current includes a voltage signal.

12. The apparatus of claim 1, further comprising: A control element having a conductive control layer adjacent to one or more insulating layers, the conductive control layer and the one or more insulating layers defining a second aperture of the control element, through which a charged droplet passes after passing through the aperture of the sensor element, wherein the conductive control layer is a second segmented conductive layer having a second plurality of separate segments electrically independent of each other and arranged around the periphery of the second aperture; and A voltage controller electrically coupled to each of the second plurality of separate segments, wherein each of the second plurality of separate segments is positioned to generate an electric field to control the trajectory of the charged droplet as it passes through the second aperture, the voltage controller being configured to apply a voltage to each of the second plurality of separate segments to generate the electric field.

13. The apparatus of claim 12, wherein, The computing device includes: Processor; and A non-transitory computer-readable storage medium that communicates with the processor, the non-transitory computer-readable storage medium storing processor-executable instructions that, when executed by the processor, cause the processor to perform operations including: Receive signals from the circuit elements; The position of the charged droplet is determined based on the signal; Based on the position of the charged droplet, the velocity of the charged droplet, and / or the predetermined position of the target, determine a group of voltages to be applied to the second plurality of separate segments; and The voltage controller is controlled to apply the voltage group to the second plurality of separate segments.

Images