Dynamic wide-volume range pipette

Abstract

To provide a multivolume liquid dispenser capable of aspirating and dispensing liquids across a broader range of liquid volumes without sacrificing accuracy and / or precision.SOLUTION: Such a pipet includes a body and a fluid displacement assembly with a small plunger element slidably received in a larger plunger element, where each of the larger and small plunger elements is movable within a vacuum chamber for precise and accurate control of the displacement of fluid, such as air. This allows a single device to aspirate and dispense a broad range of liquids in a dynamic, accurate and precise manner. In addition, the devices disclosed herein also include a multi-tiered spring-loaded ejection mechanism to thereby allow a user to use and eject pipette tips of different sizes.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Application No. 62 / 976,412, filed on February 14, 2020, the entire content of which is incorporated herein by reference.

[0002] (Field of the Invention) The present invention generally relates to pipetting devices that can dispense (or supply or metered - supply) liquid over a wide range of volumes. In particular, the present specification discloses an electronic pipette having a motor - driven piston system that includes a set of nested plunger elements (or nested plunger elements) with separate displacement chambers provided within a single device.

Background Art

[0003] (Background of the Invention) Pipettes and other similar liquid - dispensing devices are commonly used in laboratories and field research for liquid administration. A typical pipette includes a piston that can move within a cylinder, and the piston directs liquid into a disposable tip (or single - use tip) attached to the dispensing end of the pipette and serves to dispense the liquid from the disposable tip. The liquid volume is usually adjustable. The piston is moved either manually (e.g., by the force applied to a button) or by an electronic motor and associated control system. Electronic pipettes have a control system and associated user interface, and such control systems and associated user interfaces can, for example, set the volume and other required pipette functions and provide commands for performing operations. Once the desired function is selected and the volume and other settings are entered, pressing an operation switch automatically executes the piston movement.

[0004] Pipettes are generally used to dispense liquid volumes less than approximately 1 mL, typically ranging from approximately 0.5 μL to approximately 1 mL. However, as those skilled in the art will understand, current pipetting technology does not allow for the dispensing of liquid volumes across this entire range using a single fluid displacement device, and in particular, it is not possible to dispense liquid volumes across this entire range without sacrificing accuracy and precision. Typical wet lab work requiring the dispensing of such a range of liquids requires the use of three to four different pipette devices, each optimized for accurate and precise aspiration / dispensing of a subset of such volume ranges. For example, researchers typically use a 20 μL pipette to dispense fluid volumes in the range of approximately 2 μL to 20 μL, a 200 μL pipette to dispense fluid volumes in the range of approximately 20 μL to 200 μL, and a 1000 μL pipette to dispense fluid volumes in the range of approximately 100 μL to 1000 μL. The need to use multiple devices complicates the work area and increases costs.

[0005] Therefore, there is a need for a single pipetting device that can aspirate and dispense liquids over a wider range of liquid volumes without sacrificing accuracy and / or precision. [Overview of the Initiative]

[0006] This specification discloses multi-volume pipette devices (or pipette devices) capable of accurately and precisely aspirating and dispensing liquids over a wide volume range. In particular, the devices disclosed herein preferably employ nested plunger elements (or plunger elements nested within each other) that operate in different (or distinct) vacuum chambers for air displacement, thereby causing the aspiration of substantially equal volumes of liquid. The novel nested plunger design enables the device to dynamically switch seamlessly and quickly from a low volume range to a high volume range.

[0007] In one abstract, the present invention relates to a pipette comprising a body and a fluid transfer assembly, wherein the body has an open end that allows for the introduction of fluid into the body and the discharge of fluid from the body, and the fluid displacement assembly (or fluid displacement assembly) comprises a first vacuum chamber, a first plunger element, a second vacuum chamber, and a second plunger element. In this abstract, the first vacuum chamber has a first bore (or first bore) having a first fluid inlet. The first plunger element is slidably positioned within the first bore and can move between a closed position (closed position at the first fluid inlet) and an open position. When the first plunger element is in the open position, the first fluid inlet is in fluid communication with the open end of the body. The second vacuum chamber comprises a second bore within the first plunger element and has a second fluid inlet. The second plunger element is slidably positioned within the second bore and can move between a closed position (closed position at the second fluid inlet) and an open position. When the second plunger element is in the open position, the second fluid inlet is in fluid communication with the opening end of the body. The design of such a pipette also features an electronic drive unit for operating the first and second plunger elements. The electronic drive unit comprises a first motor operably connected to the first plunger element and configured to actuate the first plunger element between a closed and open position within the first bore, and a second motor operably connected to the second plunger element and configured to actuate the second plunger element between a closed and open position within the second bore. The first and second motors are controlled by a control system, which is controlled via a user interface for operating the pipette.The second plunger element is in the closed position if the first motor causes the first plunger element to move to the open position by a distance such that the volume of first liquid drawn by the pipette device is approximately equal to the volume of fluid displaced (or pushed aside) by the movement of the first plunger element. Similarly, the first plunger element is in the closed position if the second motor causes the second plunger element to move to the open position by a distance such that the volume of second liquid drawn by the pipette device is approximately equal to the volume of fluid displaced (or pushed aside) by the movement of the second plunger element. Additionally, the movement of the first plunger element from the open position to the closed position may result in the precise dispensing of the first liquid volume from the pipette, or the movement of the second plunger element from the open position to the closed position may result in the precise dispensing of the second liquid volume from the pipette. In some embodiments, the fluid being displaced (or pushed aside) is air.

[0008] In one embodiment, the range of the first liquid volume has an upper limit greater than the upper limit of the range of the second liquid volume. However, in another embodiment, the ranges of the first and second liquid volumes overlap. In some embodiments, the first liquid volume is in the range of about 10 μL to about 1500 μL. In other embodiments, the second liquid volume is in the range of about 0.1 μL to about 200 μL. Additionally, both the first and second plunger elements have a cylindrical (or cylindrical) shape, and the first cross-sectional diameter of the first plunger element is larger than the second cross-sectional diameter of the second plunger element. For example, in one embodiment, the first cross-sectional diameter is about 3 mm to about 20 mm, and the second cross-sectional diameter is about 0.5 mm to about 5 mm. In some embodiments, the ratio of the second cross-sectional diameter to the first cross-sectional diameter is about 1:1.1 to about 1:40.

[0009] In some embodiments, a first motor is operably connected to a first plunger element by a first piston, and a second motor is operably connected to a second plunger element by a second piston. Furthermore, the first motor, the second motor, or both the first and second motors may be selected from a variety of suitable motors, but are not limited to the group consisting of various suitable motors, including servo motors, stepper motors, and linear actuator motors.

[0010] In some embodiments, the pipette body further comprises a pipette housing and a dispenser housing, wherein a fluid displacement assembly is at least partially located within the dispenser housing, and an electronic drive unit is located within the pipette housing. In some embodiments, the dispenser housing comprises a first portion having a peripheral surface configured for mounting a pipette tip. In such embodiments, the dispenser housing may further comprise a second portion having a peripheral surface configured for mounting a pipette tip. The first portion may have a cross-sectional diameter larger than the cross-sectional diameter of the second portion.

[0011] Another aspect of the present invention is a method for adjusting the volume (or volume capacity, volumetric capacity, volumetric processing volume or volumetric capacity) of a pipette, the method comprising the steps of: receiving a requested volume requested by a user in a control module; determining a volumetric range in which the received requested volume will be contained in the control module; and controlling a first motor or a second motor by the control module. In such exemplary methods, the first motor moves the first plunger element from a closed position to an open position in a first vacuum chamber by a distance such that a first liquid volume drawn by the pipette device is defined by an amount approximately equal to the fluid volume displaced (or pushed aside) by the movement of the first plunger element, or the second motor moves the second plunger element from a closed position to an open position in a second vacuum chamber by a distance such that a second liquid volume drawn by the pipette device is defined by an amount approximately equal to the fluid volume displaced (or pushed aside) by the movement of the second plunger element. In such a method, the second vacuum chamber is located within the first plunger element, and the second plunger element is slidably received within the second vacuum chamber of the first plunger element. Such a method may include the step of controlling a first motor or a second motor, which may include controlling the first motor or the second motor so that the first motor moves the first plunger element from an open position to a closed position within the first vacuum chamber so that a first liquid volume is dispensed, or so that the second motor moves the second plunger element from an open position to a closed position within the second vacuum chamber so that a second liquid volume is dispensed.

[0012] In some embodiments of such a method, the fluid that is displaced (or pushed aside) by the movement of either the first or second plunger element is air. In other embodiments, the range of the first liquid volume (e.g., about 10 μL to about 1500 μL) may have a greater upper limit than the upper limit of the range of the second liquid volume (e.g., about 0.1 μL to about 200 μL), but the ranges of the first and second liquid volumes may overlap.

[0013] In another embodiment of the above method, a first motor is operably connected to a first plunger element by a first piston, and a second motor is operably connected to a second plunger element by a second piston. In yet another embodiment, the first plunger element is cylindrical and has a first cross-sectional diameter (e.g., about 3 mm to about 20 mm), and the second plunger element is cylindrical and has a second cross-sectional diameter (e.g., about 0.5 mm to about 5 mm), with the first cross-sectional diameter being larger than the second cross-sectional diameter. In some embodiments, the ratio of the second cross-sectional diameter to the first cross-sectional diameter is about 1:about 1.1 to about 1:about 40. In other embodiments, the first motor, the second motor, or both the first and second motors are selected from the group consisting of servo motors, stepper motors, and linear actuator motors.

[0014] A further aspect of the present invention is a multi-volume liquid dispenser, which comprises a long body having a pipette housing and a dispenser housing, and a motor assembly having a first motor and a second motor located within the pipette housing and controlled by a control system. The dispenser housing comprises an open end that allows air to be introduced into and out of the dispenser housing, and the dispenser housing is configured to be fitted with a syringe or tip (or tip member, tip), and the control system is controlled via a user interface for operating the multi-volume liquid dispenser. In a multi-volume liquid dispenser of this particular design, a first motor is operablely connected to a large plunger and operates the large plunger between a closed position and an open position within a large cylindrical vacuum chamber, the movement of the large plunger to the open position causing a displacement (or displacement) of air into the large cylindrical vacuum chamber approximately equal to the first volume of liquid drawn in by the multi-volume liquid dispenser; a second motor is operablely connected to a small plunger and operates the small plunger between a closed position and an open position within a small cylindrical vacuum chamber located within the large plunger, the movement of the small plunger to the open position causing a displacement (or displacement) of air into the small cylindrical vacuum chamber approximately equal to the second volume of liquid drawn in by the multi-volume liquid dispenser; furthermore, when the small plunger moves to the open position, the large plunger is in the closed position, and when the large plunger moves to the open position, the small plunger is in the closed position. In some embodiments, the first motor is further configured to actuate a large plunger from an open position to a closed position to dispense a first volume of liquid from a multi-volume liquid dispenser, and the second motor is further configured to actuate a small plunger from an open position to a closed position to dispense a second volume of liquid from a multi-volume liquid dispenser.

[0015] In one embodiment, the first liquid volume is in the range of approximately 10 μL to approximately 1500 μL, and the second liquid volume is in the range of approximately 0.1 μL to approximately 200 μL. Furthermore, the large plunger has a larger cross-sectional diameter than the small plunger. For example, the ratio of the cross-sectional diameter of the small plunger to the cross-sectional diameter of the large plunger is approximately 1:1.1 to approximately 1:40. Similar to the design described above, the plungers are driven by a pair of motors (or a pair of motors or a set of motors), and such motors can be selected from the group consisting of any number of suitable motors, but are not limited, including servo motors, stepper motors, or linear actuator motors.

[0016] In certain embodiments, the syringe or tip is attached to the dispenser housing by interference fit (or interference fit). In other embodiments, the dispenser housing has at least two syringe or tip mounting surfaces, the peripheral surface of the first mounting surface being larger than the peripheral surface of the second mounting surface.

[0017] In some embodiments, a multi-volume liquid dispenser includes a multi-tiered spring-loaded ejector mechanism (or a multi-tiered spring-loaded ejector mechanism). In such embodiments, the multi-tiered spring-loaded ejector mechanism may include an ejection element (or ejector element or eject element) having an upper ejection portion (or upper ejector portion or upper eject portion) biased upward by a first biasing element, and a lower ejection portion (or lower ejector portion or lower eject portion) biased upward by a second biasing element. In such a design, when a user applies a first force to the multi-stage spring-loaded ejector mechanism, the upper ejection portion contacts the lower ejection portion, the lower ejection portion moves to a first position, and the syringe or tip is ejected (or discharged or removed) from the first mounting surface; or when a user applies a second force to the multi-stage spring-loaded ejector mechanism, the upper ejection portion contacts the lower ejection portion, the lower ejection portion moves to a second position, and the syringe or tip is ejected (or discharged or removed) from the second mounting surface.

[0018] Other features and advantages of the present invention will become apparent by referring to the drawings and the following detailed description and examples. [Brief explanation of the drawing]

[0019] [Figure 1A] Figure 1A shows a side view of an embodiment of the pipette device described herein. [Figure 1B] Figure 1B shows an embodiment of a multi-tiered (or multiple stepped, layered, or multi-tiered) tip ejector assembly. [Figure 2]Figure 2 shows aspects of the motor-piston assembly and fluid displacement system of the pipette device described herein. [Figure 3] Figure 3 is an exploded view of aspects of the motor assembly and fluid displacement system of the pipette device described herein. [Figure 4A] Figure 4A shows aspects of the large plunger element and the small plunger element. [Figure 4B] Figure 4B is a bottom view of the large plunger element. [Figure 5A] Figure 5A shows a pipette device with a large plunger element and a small plunger element in a closed position, with respect to aspects of the pipette device during the operation of FIGS. 5A-5D. [Figure 5B] Figure 5B shows a pipette device in which the large plunger element is moving towards the open position and the end of the small plunger element is in contact with the seat in the small vacuum chamber (closed position), with respect to aspects of the pipette device during the operation of FIGS. 5A-5D. In such a mode, the pipette device is adapted to aspirate and dispense liquid by displacement of air in the large vacuum chamber. [Figure 5C] Figure 5C represents a pipette device with a large plunger element and a small plunger element in a closed position, with respect to aspects of the pipette device during the operation of FIGS. 5A-5D. [Figure 5D] Figure 5D shows a pipette device in which the small plunger element is moving towards the open position and the end of the large plunger element is in contact with the seat in the large vacuum chamber (closed position), with respect to aspects of the pipette device during the operation of FIGS. 5A-5D. In such a mode, the pipette device is adapted to aspirate and dispense liquid by displacement of air in the small vacuum chamber. [Figure 6A] Figure 6A shows a side view of the pipette device aspect, with respect to another aspect of the pipette device of FIGS. 6A-6E. [Figure 6B]Figure 6B shows an in-line motor-driven piston assembly and a fluid displacement system of the pipette device aspect for another aspect of the pipette devices of FIGS. 6A-6E. [Figure 6C] Figure 6C shows an assembly of a small plunger and a large plunger of the pipette device aspect for another aspect of the pipette devices of FIGS. 6A-6E. [Figure 6D] Figure 6D is a bottom view of a large plunger element for another aspect of the pipette devices of FIGS. 6A-6E. [Figure 6E] Figure 6E is an exploded view of an aspect of the motor assembly and the fluid displacement system of the pipette device of this specification for another aspect of the pipette devices of FIGS. 6A-6E. [Figure 7] Figure 7 shows a side view of a pipette device aspect with a cantilever-motor connection element. [Figure 8A] Figure 8A represents a pipette device having a large plunger element and a small plunger element in a closed position in a pipette device aspect of a cantilever design during operation of FIGS. 8A-8D. [Figure 8B] Figure 8B shows a pipette device in which the large plunger element moves towards an open position and the small plunger element is in a closed position in a pipette device aspect of a cantilever design during operation of FIGS. 8A-8D. In such a mode, the pipette device is adapted to aspirate and dispense liquid by displacement of air in a large vacuum chamber. [Figure 8C] Figure 8C represents a pipette device having a large plunger element and a small plunger element in a closed position in a pipette device aspect of a cantilever design during operation of FIGS. 8A-8D. [Figure 8D]Figure 8D shows a pipette device in operation as shown in Figures 8A-8D, where the small plunger element is moving toward the open position and the large plunger element is in the closed position. In this mode, the pipette device is configured to aspirate and dispense liquid by displacement of air in a small vacuum chamber. [Modes for carrying out the invention]

[0020] (Detailed description of the invention) The pipette devices described herein are capable of transferring a large range of liquid volumes through a novel dispenser design comprising two or more motor-driven plunger elements that function in combination to provide multiple (or many) volumetric air displacement chambers (i.e., vacuum chambers). In particular, each vacuum chamber can be optimized for precise displacement (or pushing, moving, or displacing) of a fluid such as air, spanning a different volumetric range. When a vacuum is formed in the chamber, a fluid (e.g., air) enters the chamber, causing the pipette to aspirate approximately equal volumes of liquid. Furthermore, each plunger element is driven by an individual (or separate) motor, thereby enabling rapid and dynamic switching from one vacuum chamber to the next, allowing the user to seamlessly pipette liquids over a wide range of volumes. In this manner, the pipette device can aspirate and dispense liquids over a wider range of volumes than currently available devices. Multiple plunger elements (or a number of plunger elements) are contained within a device housing, and the physical movement of the plungers within the housing creates a vacuum. In a preferred embodiment, the plungers are at least partially contained within a hole (or bore) or hollow space in the housing or casing of the device's dispenser section. As the plunger elements move within the hollow space or hole of the vacuum chamber, a fluid (e.g., air) is drawn into or out of the chamber, thereby drawing in or dispensing a corresponding volume of liquid from the pipette tip, respectively. The plungers may consist of a hard (or rigid) material such as plastic or metal. Furthermore, the plungers are preferably cylindrical, although other shapes are also possible.As described below, in a preferred embodiment of the present invention, at least two plunger elements are suitable for use, and the plungers are arranged such that the plungers are cylindrical and nested together.

[0021] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, standard techniques are used. While similar or equivalent methods and materials may be used in the practice or trial of this disclosure, suitable methods and materials are described below. Materials, methods and examples are given merely as examples and are not intended to limit the invention. All publications, patents and other documents referenced herein are incorporated herein by reference in whole or in their entirety.

[0022] As used herein, singular forms such as "a," "an," and "the" also encompass plural meanings unless the context clearly indicates otherwise.

[0023] The term "about" indicates a variation in the numerical value of a measurement (e.g., diameter, area, length, volume) due to the typical error rates of the device used to obtain such measurement.

[0024] In this specification, the term "approximately equivalent" refers to the volume of fluid displaced (or pushed aside, moved, or shifted) by the device compared to the volume of liquid drawn in by the device, meaning that the volume of fluid (e.g., air) displaced by the movement of the plunger element in the vacuum chamber is not exactly equal to the volume of liquid drawn into the tip attached to the end of the device due to the difference in density between the fluid and the liquid. The device design is calibrated (or adjusted) to take such factors into account and to a degree satisfactory to those skilled in the art.

[0025] "Interference fit" or "friction fit" is used herein interchangeably to refer to a fastening between two parts that is achieved by friction after the parts have been pushed together.

[0026] The designations used herein, such as “up,” “down,” “upward,” “downward,” “horizontal,” and “vertical,” refer to the orientation of the pipette device, specifically the orientation in which the pipette housing has the actuating member or push button at the top and the dispensing end at the bottom (see, for example, Figure 1A). In such an orientation, the pipette tip, fixed or attached to the dispensing end of the dispenser housing, may be directed toward a vessel located below it for the aspiration or delivery of liquid.

[0027] Figures 1A to 4 illustrate embodiments of the pipette device (or pipetting device) of the present invention. The pipette device 10 generally has an elongated (or slender, elongated, or rod-shaped form, with a top-side drive section 12 that includes all of the drive unit and associated elements enclosed in a pipette housing 15. The pipette device 10 also generally includes a bottom-side fluid displacement (or fluid pushing, fluid movement, or fluid displacement) and fluid dispensing section 14, which includes a dispenser housing 52 that includes at least some of the plunger elements 60, 70. A cylindrical push-button-shaped actuate element (or operating element) 20 protrudes upward from the pipetting housing 15 of the drive section 12. The actuate element 20 is axially movable within the pipette housing 15 and is used by the user (or operator) to bring about fluid aspiration or fluid dispensing (or fluid distribution or dispensing) by the pipette device.

[0028] The bottom or dispensing end (or dispensing end) of the pipette device described herein includes at least one holder or seat element (or chair element or pedestal element) to which a pipette tip for liquid aspiration is attached (or fastened). The dispensing end housing or casing preferably includes two or more seat portions or holder portions, one portion of the dispensing housing configured to accommodate a pipette tip of a certain volume, and the other portion of the dispensing housing configured to accommodate a pipette tip of a different volume. For example, a typical dispensing housing may include a holder portion for a pipette tip capable of aspirating liquid in a volume (or capacity) in the range of about 10 μL to about 1500 μL, preferably the pipette tip capable of aspirating liquid in a volume in the range of about 50 μL to about 1000 μL. In this embodiment, the dispenser housing includes a second holder portion for a pipette tip capable of drawing liquid in volumes ranging from approximately 0.50 μL to approximately 200 μL. Therefore, the shape / design (or construction) of the dispensing section is suitable for accommodating pipette points / pipette tips of different sizes.

[0029] Figures 1A and 2 show approximately 10 μL to approximately 1500 μL (for example, approximately 10 μL, approximately 15 μL, approximately 20 μL, approximately 25 μL, approximately 30 μL, 40 μL, approximately 50 μL, approximately 60 μL, approximately 70 μL, approximately 80 μL, approximately 90 μL, approximately 100 μL, approximately 110 μL, approximately 120 μL, approximately 130 μL, approximately 140 μL, approximately 150 μL, approximately 160 μL, approximately 170 μL, approximately 180 μL, approximately 190 μL, approximately 200 μL, approximately 210 μL, approximately 220μL, about 230μL, about 240μL, about 250μL, about 260μL, about 270μL, about 280μL, about 290μL, about 300μL, about 350μL, about 400μL, about 450μL, about 500μL , about 550μL, about 600μL, about 650μL, about 700μL, about 750μL, about 800μL, about 850μL, about 900μL, about 950μL, about 1000μL, about 1100μL, about 1200μL, about 1 A large pipette tip capable of aspirating liquid volumes in the range of 300 μL, approximately 1400 μL, or approximately 1500 μL, and a nozzle capable of aspirating approximately 0.1 μL to approximately 200 μL (for example, approximately 0.1 μL, approximately 0.2 μL, approximately 0.3 μL, approximately 0.4 μL, approximately 0.5 μL, approximately 1.0 μL, approximately 1.5 μL, approximately 2.0 μL, approximately 2.5 μL, approximately 3.0 μL, approximately 4.5 μL, approximately 5.0 μL, approximately 10 μL, approximately 15 μL, approximately 20 μL, approximately 25 μL, approximately An exemplary dispenser housing 52 is shown, configured to accommodate a small pipette tip capable of aspirating liquid volumes in the range of 30 μL, approximately 40 μL, approximately 50 μL, approximately 60 μL, approximately 70 μL, approximately 80 μL, approximately 90 μL, approximately 100 μL, approximately 110 μL, approximately 120 μL, approximately 130 μL, approximately 140 μL, approximately 150 μL, approximately 160 μL, approximately 170 μL, approximately 180 μL, approximately 190 μL, and approximately 200 μL. In some embodiments, the first liquid volume range is approximately 50 μL to approximately 1000 μL, and the second liquid volume range is approximately 0.5 μL to approximately 200 μL. Thus, the dispenser housing 52 includes a stepped structure (or layered structure or tiered structure) having a large tip holder 48 and a small tip holder 49. In this stepped structure, the outer circumference of the device in the large tip holder portion is wider (or larger) than the outer circumference of the small tip holder portion.Therefore, the stepped design allows for the fitting or securing of different sized tips due to interference fit or friction fit, and the pipette tip is fixed to the dispenser housing 52 and secured to either the large tip holder 58 or the small tip holder 59 by utilizing the circular force of the pipette tip that resists the tip holder portion (or tip holder portion) of the pipette device. Therefore, the pipette device 10 has a volume range of approximately 0.1 μL to approximately 1500 μL (for example, approximately 0.1 μL, approximately 0.2 μL, approximately 0.3 μL, approximately 0.4 μL, approximately 0.5 μL, approximately 1.0 μL, approximately 1.5 μL, approximately 2.0 μL, approximately 2.5 μL, approximately 3.0 μL, approximately 4.5 μL, approximately 5.0 μL, approximately 10 μL, approximately 15 μL, approximately 20 μL, approximately 25 μL, approximately 30 μL, approximately 40 μL, approximately 50 μL, approximately 60 μL, approximately 70 μL, approximately 80 μL, approximately 90 μL, approximately 100 μL, approximately 110 μL, approximately 120 μL, approximately 130 μL, approximately 140 μL, approximately 150 μL, approximately 160 μL, approximately 170 μL, approximately 180 μL Liquids can be aspirated and dispensed in L (approximately 190 μL, 200 μL, 210 μL, 220 μL, 230 μL, 240 μL, 250 μL, 260 μL, 270 μL, 280 μL, 290 μL, 300 μL, 350 μL, 400 μL, 450 μL, 500 μL, 550 μL, 600 μL, 650 μL, 700 μL, 750 μL, 800 μL, 850 μL, 900 μL, 950 μL, 1000 μL, 1100 μL, 1200 μL, 1300 μL, 1400 μL, or 1500 μL). In certain embodiments, the pipette device 10 can aspirate and dispense liquids in a volume range of approximately 0.5 μL to approximately 1000 μL. As will be described in more detail below, the device of the present invention can accurately and precisely aspirate and dispense such a wide range of liquid volumes by designing its dual-motor driven (or two-motor driven) piston and plunger elements.

[0030] As those skilled in the art will understand, typical pipettes utilize disposable pipette tips, which must be quickly removed and replaced between handling different liquid samples to prevent contamination or undesirable mixing of liquids. In this regard, the pipette devices of this disclosure may be devices that have an ejector mechanism (or dispensing mechanism) for quickly and easily removing the pipette tip without the user having to touch the tip itself.

[0031] An ejection mechanism suitable for use in the pipette device of the present invention includes a multi-stage spring-loaded ejector shown in Figures 1A and 1B, which is a single ejection assembly (or discharge or removal assembly) capable of ejecting (or discharging or removing) tips of different sizes from different mounting points on the dispensing portion of the pipette. In the embodiments shown in Figures 1A and 1B, the pipette device 10 has an ejection element 30 (e.g., a push button) connected to an ejection sleeve (or ejection sleeve, discharge sleeve or removal sleeve) 40. A suitable embodiment of the ejection sleeve 40 may include an upward ejection sleeve (or upward ejection sleeve) 41 that extends to have substantially the same length as the pipette housing 15. The upper eject sleeve 41 has a tapered section 42 beyond the pipette housing point toward the intermediate eject sleeve 43, and the intermediate eject sleeve 43 includes a mechanical catch element 46. The upper eject sleeve 41 is spring-loaded at its top by a bias spring 35, which holds the eject assembly in its highest mechanical position, while the user can mechanically move the sleeve downward against the bias spring 35. When the eject sleeve 40 is moved downward, the mechanical catch element 46 comes into contact with the lower eject sleeve 44.

[0032] The lower eject sleeve 44 is also spring-loaded by a biasing spring 51 and held in its highest position. When the large tip is in the large tip holder 48, the upper eject sleeve 40 is moved downward until it reaches a point where it increases the tension from the biasing spring 51 on the lower eject sleeve 44. Within the range of such movement (or the range within which the upper eject sleeve moves in this manner), pressure is applied from the large tip eject edge 45, releasing the large tip from the large tip holder 48.

[0033] If the large tip is not present, the user pushes down the eject element 30 until the mechanical catch element 46 engages with the lower eject sleeve 44. At this point (or from this point) the user continues to push down, which leads to the involvement (or engagement) of the biasing spring 51 of the lower eject sleeve 44, causing the lower eject sleeve 44 to move downward and the small tip to be released from the small tip holder 49. In this design embodiment, the large tip holder also doubles as the small tip eject edge, and an O-ring 54 is included to ensure that the large tip holder remains airtight.

[0034] In other embodiments, a multi-stage spring-loaded ejector of a pipette device includes two separate ejector elements (e.g., buttons), and the user presses either the large tip ejector element or the small tip ejector element, depending on whether the large tip is attached to the large tip holder or the small tip is attached to the small tip holder. For example, the user presses the large tip ejector element, thereby moving the eject sleeve downward to eject the large pipette tip from the large tip holder, or presses the small tip ejector element, thereby moving the eject sleeve downward to eject the small tip from the small tip holder. In some embodiments, both the large tip ejector element and the small tip ejector element may move the same eject sleeve, although they are at different distances corresponding to the large tip holder and the small tip holder. In other embodiments, each of the large tip ejector element and the small tip ejector element moves a different eject sleeve, thereby ejecting either the large tip or the small tip, respectively.

[0035] As described above, the pipette device of this disclosure is capable of aspirating and dispensing a wide range of liquid volumes, largely due to its motor-driven nesting plunger element design (a design in which at least one plunger element is slidably received by another plunger element). The movement of each plunger element within the corresponding vacuum chamber creates an "in-chamber vacuum" which causes the inflow of fluid (e.g., air). Such fluid displacement (or fluid pushing, fluid movement, or fluid displacement) assists in the aspiration of approximately the same volume of liquid into the attached pipette tip. In this way, each plunger element can add a vacuum chamber to the device, and each vacuum chamber has a different volume (or volumetric capacity) for the inflow of fluid (e.g., air). In a preferred embodiment, the movement of the plunger element within its vacuum chamber creates a vacuum which causes air displacement. In other words, air enters the vacuum chamber. This air displacement causes a corresponding volume of liquid to be drawn into the tip attached to the end of the device.

[0036] Furthermore, a reduced volume vacuum chamber is created by an arrangement (or configuration) of nested plunger elements that reduces the cross-sectional area. For example, one plunger element contains an internal space or bore into which another smaller plunger element is slidably received or positioned. Thus, as such a relatively smaller plunger element moves upward and downward within a relatively larger plunger element, another vacuum chamber is created, albeit with a relatively smaller volume. Therefore, the pipette device described herein allows for rapid and dynamic switching from one vacuum chamber to another by manipulating different plunger elements, and is capable of accurately and precisely dispensing a wider and larger range of liquid volumes compared to devices currently on the market. The pipette devices disclosed herein may have any number of nested plunger elements and vacuum chambers, while the non-limiting exemplary embodiments of the pipette devices shown in Figures 1A to 8D have two plunger elements and two vacuum chambers. In a preferred embodiment, the plunger elements are cylindrical (or have a cylindrical shape).

[0037] In a preferred embodiment, the pipette device includes at least two plunger elements, one of which is slidably housed within the other plunger element to form a nested or concentric plunger element arrangement (or nested or concentric plunger element configuration). In particular, the pipette device includes a large plunger element that slides within a vacuum chamber in the housing, and a small plunger element that is slidably received within the receptacle or bore of the large plunger element, resulting in another relatively smaller vacuum chamber (or even smaller vacuum chamber) (see, for example, Figures 2 to 4). The movement of the plunger elements is controlled by the motor-driven operation of pistons within the device. The movement of the plunger elements controls the volume of the corresponding vacuum chamber and thus the amount of fluid (e.g., air) displaced by the vacuum chamber. Ultimately, the displacement of the fluid draws approximately the same volume of liquid into the pipette tip. Preferably, the movement of the plunger elements is controlled by a set of motor-driven pistons housed within the drive section of the device.

[0038] As described above, the plunger elements are preferably cylindrical in shape with different cross-sectional diameters, so as to result in a nested plunger design with separate (or distinct) vacuum chambers having different volumes. For example, in one particular embodiment, the cross-sectional diameter of the large plunger element may typically be about 3 mm to about 20 mm, for example, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. In a preferred embodiment, the cross-sectional diameter of the large plunger element is about 5 mm to about 15 mm, more preferably about 6 mm to about 10 mm. For example, in one embodiment, the cross-sectional diameter of the large plunger element is about 7 mm to about 8 mm. For small plunger elements, the cross-sectional diameter may be approximately 0.5 mm to approximately 5 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, or 5.0 mm (provided that the cross-sectional diameter of the small plunger element is smaller than the cross-sectional diameter of the large plunger element, allowing for nested arrangement). In some embodiments, the cross-sectional diameter of the small plunger element is between approximately 1 mm and approximately 3 mm. For example, in one particular embodiment, the cross-sectional diameter of the small plunger element is between approximately 1.4 mm and approximately 1.7 mm.

[0039] The nesting plunger arrangement suitable for use in this design has a ratio of the cross-sectional diameter of the small plunger element to the cross-sectional diameter of the large plunger element that enables a lightweight and compact design while ensuring efficient fluid displacement (or fluid pushing, fluid movement, or fluid displacement) in handheld (or portable or handheld) pipettes. In some embodiments, the ratio of the diameter of the small plunger element to the diameter of the large plunger element is 1:1.1 to 1:40, for example, 1:1.1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, and 1:40. In other embodiments, the ratio of the diameter of the small plunger element to the diameter of the large plunger element is 1:2 to 1:10. For example, in one particular embodiment, such a ratio is 1:5.

[0040] Next, the configuration and function of the nested plungers will be described in more detail. As shown in Figures 2, 3, 4A, and 4B, the drive section 12 includes a motor assembly 16 housed in a pipette housing 15. The motor assembly 16 is connected to a large plunger assembly 18 via a mounting element 115. The mounting element 115 has a pair of motor assembly anchors 160 that can be attached to the motor assembly 16 by screws (e.g., screws through screw holes 162), nails, adhesive, etc. The large plunger element 60 is mounted on the mounting element 115 and partially positioned within the dispenser housing 52. The dispenser housing 52 includes a hole or fluid passage 85 through its center and an inlet 50 for receiving fluids such as liquids or gases (e.g., air) from the external environment. The large plunger element 60 is slidably received within the hole or fluid passage in the dispenser housing 52. The movement of the large plunger element 60 within the dispenser housing 52 creates a large vacuum chamber 55.

[0041] Figure 2 shows a typical arrangement in which the large plunger element 60 and the dispenser housing 52 are oriented vertically. The large plunger element is configured to move along this vertical axis A. The large plunger element 60 can move or actuate between a closed position and an open position. In the closed position, the large plunger element is at the bottom of its axis of movement (i.e., the fluid inlet 86 of the dispenser housing 52). Thus, the end 145 of the large plunger element 60 is in contact with the seat 75 inside the dispenser housing 52 and at the bottom of the large vacuum chamber 55. In the embodiments shown in Figures 2, 4A, and 4B, an O-ring 56 may be nested inside the bottom of the large plunger element 60 to ensure that the seal is airtight. In the open position, the large plunger element 60 moves toward the top of its axis of movement. In the open position, the large plunger element 60 moves away from the sheet 75, thereby increasing the volume of the large vacuum chamber 55. The large vacuum chamber 55 reaches its maximum volume when the large plunger element 60 is fully open and at the top of its axis of movement. When the large plunger element 60 is in the open position, air can be displaced into the large vacuum chamber 55 from the external environment through the fluid inlet 86 in the floor of the large vacuum chamber 55.

[0042] In a preferred embodiment, the large plunger element 60 has an internal space or passage 155 with an opening 88 at its end 145 for receiving a fluid such as air (see Figures 2, 4A, and 4B). In such an embodiment, the small plunger element 70 and the large plunger element 60 are nested together. The small plunger element 70 is slidably received together with the internal space or passage 155 of the large plunger element 60, and the movement of the small plunger element 70 along the vertical axis A within the large plunger element 60 forms a small vacuum chamber 65. Therefore, the small plunger element 70 necessarily has a smaller cross-sectional area than the large plunger element 60. In such an embodiment, the small plunger element 70 is typically solid (i.e., does not have an internal fluid passage). However, in embodiments having three or more vacuum chambers, the small plunger element 70 may have an internal space for slidably receiving yet another plunger element.

[0043] The small plunger element 70 is also movable between a closed position and an open position. In the closed position, the small plunger element 70 is located at the bottom of its axis of movement (i.e., the opening 88 of the large plunger element 60). Therefore, the end 135 of the small plunger element 70 is in contact with the sheet 80 inside the large plunger element 60 and at the bottom of the small vacuum chamber 65. Consequently, the displaced (or pushed aside, moved, replaced or displaced) air cannot enter the small vacuum chamber 65. In the open position, the small plunger element 70 moves toward the top of its axis of movement. In the open position, the small plunger element 70 moves away from the sheet 80, thereby increasing the volume of the small vacuum chamber 65. Thus, the displaced air can enter the small vacuum chamber 65 through the fluid inlet 88 of the large plunger element 60.

[0044] In some embodiments, the device has an O-ring 140 at the end of the small plunger element 70 to ensure a good seal when the small plunger element 70 is in the closed position. Furthermore, the use of a biasing spring 90 can bias the small plunger element 70 toward the open position. When the small plunger element 70 is in the fully open position and at the top of its movable axis, the small vacuum chamber 65 has its maximum volume (or maximum capacity). When the small plunger element 70 is in the closed position, the small vacuum chamber 65 is also closed, and no fluid such as air enters the small vacuum chamber 65.

[0045] In a preferred embodiment, when the large plunger element 60 is in the "open" position, the small plunger element 70 is in the "closed" position to prevent the displaced air from moving from the large vacuum chamber 55 to the small vacuum chamber 65. Similarly, when the small plunger element 70 is in the "open" position, the large plunger element 60 is in the "closed" position to prevent the displaced air from moving to the large vacuum chamber 55. When the large plunger element 60 is in the closed position, the displaced air moves directly from the fluid inlet passage 85 through inlets 86 and 88 into the small vacuum chamber 65 located inside the large plunger element (see Figure 2). A small O-ring 56 may be nested at the bottom of the large plunger, thereby ensuring airtightness of the air passage of the small plunger when the large plunger is in the "closed" position.

[0046] While a manually operated design is conceivable, the preferred design of this pipette device utilizes an electronic motor drive system to actuate the plunger elements. In particular, the device may have separate electric motors configured to actuate each plunger element. In a preferred embodiment, the pipette device has dual motors to actuate each of two nested plunger elements. The motors respond to a control system operated by the user via an interface. In some embodiments, the plunger elements are directly connected to the motors. In other embodiments, each motor actsuates a piston connected to the plunger element. Suitable motors include, but are not limited to, servo motors, stepper motors, and linear actuator motors. In certain embodiments, the plunger elements are actuated by a stepper motor, such as a can-stack stepper motor, also known as a can-stack linear actuator motor. Each plunger can be actuated by the same type of motor or different types of motors.

[0047] Figures 2 and 3 illustrate embodiments of the present invention that utilize a dual-motor driven piston for the operation of a plunger element. As shown in Figures 2 and 3, the small plunger element 70 is connected to a small volume piston (or small-volume piston) 95. The small volume piston 95 is connected to a small piston motor 110 via a connecting element 100 (e.g., via a screw combination or mating) by a piston receiver 105. The small piston 95, the connecting element 100, and the small plunger element 70 are operably moved along axis A in response to the metering of the small piston motor 110. The small piston motor 110 is connected to a large volume piston (or large-volume piston) 130 via a motor connector element 120. Thus, the large volume piston 130, the motor connector element 120, the small piston motor 110, the small volume piston 95, the small plunger element 70, and the large plunger element 60 move as a single unit when the large volume piston 130 is actuated in response to the metering of the large piston motor 125.

[0048] In one embodiment, suitable motors are can stepper motors or can stack linear actuator motors. These motors move the piston linearly without rotation. Each of these motors is connected to a controller board that allows each motor to be operated independently or in tandem during the pipetting operation.

[0049] The operation of the pipette device is shown in Figures 5A to 5D. Figures 5A and 5B show the aspiration and dispensing of large volumes of liquid (e.g., approximately 50 μL to approximately 1000 μL). When dispensing large volumes, the user can attach a large pipette tip (e.g., a large pipette tip that dispenses volumes in the range of approximately 50 μL to approximately 1000 μL) to the end of the dispenser housing using the interference fit described above. When operating the device for aspiration of large volumes, the small plunger element 60 is in the closed position, and the end 135 of the small plunger element 70 is in contact with the seat 80 in the large vacuum chamber 55. The O-ring 140 ensures an airtight seal to prevent leakage of fluid (e.g., air) into the small vacuum chamber 65. In other words, the small plunger element can be said to be "bottomed out". In Figure 5A, the large plunger element 60 is in contact with the seat 75 of the large vacuum chamber 55. Therefore, the large plunger element 60 is also “bottomed out.” In other words, both plunger elements are in the closed position. When both plunger elements are in the closed position, no air is displaced from the external environment into either the vacuum chamber 55 or 65.

[0050] The user inputs the desired dispensing volume via an interface consisting of knobs and / or buttons, and feedback is provided via an LCD screen (or LCD display). For example, as will be understood by those skilled in the art, the actuator element 20 may be configured for volume adjustment by rotation by the user using feedback provided via the LCD screen. Such input is transmitted to a controller printed circuit board (PCB) in the pipette head, which is connected to the motors via power and communication cables. The PCB is programmed to store the operating ranges of each motor, such as the small volume range for the motor controlling the small motor and the large volume range for the motor controlling the large plunger. When a large volume range is used, the user attaches the large pipette tip to the large pipette tip holder 48, inputs the desired aspiration volume, and places the end of the large pipette tip into the liquid to be aspirated.

[0051] After setting the desired suction volume (within the large volume range), the user presses the button on the top surface 25 of the pipette, sending a signal to the large motor, causing the piston to move to a position where it is possible to draw the appropriate volume of liquid. The large piston motor 125 then moves the large volume piston 130 upward. As the large volume piston 130 moves upward, the motor connector element 120, the small piston motor 110, and the large plunger element 60 move upward simultaneously as a single unit. As the large plunger 60 moves upward along axis A and separates from the seat 75 of the large vacuum chamber 55, the volume of the large vacuum chamber 55 increases, thereby creating a vacuum and causing the corresponding displacement (or pushing, moving, replacing, or displacing) of air through the fluid inlet 50. The air rises through the fluid passage 85 of the dispenser housing 52 and enters the large vacuum chamber 55 through the fluid inlet 86. This draws the corresponding volume of liquid into the pipette tip. Next, when the actuator element 20 is pressed again by the user, the large volume piston 130 and the large plunger element 60 move downward. As the large plunger element 60 moves downward, the displaced air is displaced so that it is returned through the fluid inlet 50, and liquid is dispensed from the pipette tip.

[0052] In a particular embodiment shown in Figure 5B, the small plunger element 70 is in a closed position such that its lower end 135 contacts the seat 75 within the large plunger element 60. Therefore, air displaced from the large vacuum chamber 55 cannot enter the small vacuum chamber 65 through the fluid inlet 88 of the large plunger. In some embodiments, the device includes a sealing member, such as an O-ring 140 (see, for example, Figure 3), to prevent displaced air from leaking into the small vacuum chamber.

[0053] In some embodiments, it is desirable to eject the pipette tip after dispensing the fluid and replace the tip with a new one. The pipette devices described herein may include ejection mechanisms such as the multi-stage spring-loaded ejector mechanism shown in Figure 1B. In this particular embodiment, when the ejector element 30 is pushed down by the user, the mechanical catch element 46 contacts the lower eject sleeve 44, so that the eject sleeve 40 moves downward. If a large tip is present in the large tip holder 48, the tension from the biasing spring 51 resisting the lower eject sleeve 44 causes pressure from the large tip eject edge 45, moving the upper eject sleeve 40 downward until it reaches a contact point where the large tip is removed from the large tip holder 48.

[0054] Next, the user inserts the end of the dispenser housing into the upper opening of the pipette tip and uses downward force to attach the pipette tip to the pipette device by interference fit or friction fit to replace the pipette tip. In some embodiments, it may be desirable for the user to reduce the dispensing volume by having a smaller tip (e.g., a smaller tip configured for dispensing volumes in the range of approximately 1 μL to approximately 200 μL) retain (or fix) to the end of the dispense housing.

[0055] Figures 5C and 5D illustrate the aspiration and dispensing of small volumes of liquid (e.g., approximately 1 μL to 200 μL). As shown in Figure 5C, the small plunger element 70 and the large plunger element 60 are in the "bottomed out" or closed position. The user attaches the small pipette tip to the small pipette tip holder 49 and places the end of the small pipette tip into the liquid to be aspirationed. The device can be switched from the large volume range to the small volume range via the user interface. In a preferred embodiment, the pipette device does not include a physical switch, as the resting position is the same whether the pipette device is in large volume mode or small volume mode. Therefore, in a preferred embodiment, when the user selects a volume in the small volume range, the firmware is instructed to operate only the small motor / plunger mechanism. Conversely, when a volume in the large volume range is selected, the large motor and plunger engage. Therefore, in a preferred embodiment, this process is seamless for the user. In some embodiments, the interface associated with the control system includes an option for the user to program one or more preset volumes so that the user can quickly switch between preset volumes.

[0056] Once the desired volume within the small volume range is set, the user presses the top surface 25 of the actuator element 20. This sends a signal to the small piston motor 110, which moves the small volume piston 95 upward to a position that draws in the appropriate volume of liquid specified by the user. As shown in Figure 5D, as the small volume piston 130 moves upward, the small plunger element 70 moves upward along axis A away from the seat 80 of the small vacuum chamber 65. Thus, the small plunger element 70 transitions from the closed position to the open position. While the small plunger element 70 moves toward the open position, the volume of the small vacuum chamber 65 increases and a vacuum is formed, thereby causing a displacement of the corresponding air into the small vacuum chamber 65 through the fluid inlet 88 of the large plunger element 60 to pass through the fluid inlet 50. This draws approximately equal volumes of liquid into the pipette tip. Then, when the actuator element 20 is pressed again by the user, the small volume piston 95 and the small plunger element 70 move downward. As the small plunger element 70 moves downward against the biasing spring 90, the displaced air is displaced so that it is returned from the fluid inlet 50, and the fluid is dispensed from the pipette tip.

[0057] To eject the tip of the small pipette, the user pushes down the ejector element 30 until the mechanical catch element 46 of the intermediate eject sleeve 43 engages with the lower eject sleeve 44. At this point, the user continues to press downward, engaging (or causing the engagement of) the biasing spring 51. As the lower eject sleeve 44 moves downward, the small tip is released (or freed) from the small tip holder 49.

[0058] When the small plunger element is in operation, the large plunger element is maintained in the closed position, with its end 145 in contact with the sheet 75 on the floor of the large vacuum chamber 55. To maintain the airtightness of the small volume chamber, an O-ring 56 is nested inside the bottom of the large plunger. Therefore, the "displaced air" flowing upward through the passage 85 does not leak into the large vacuum chamber 55, but flows directly into the small vacuum chamber 65 through the fluid inlets 86 and 88.

[0059] Figures 6A–6E show another embodiment of the pipette device with an LCD screen and a rechargeable battery. The pipette device 200 includes and functions substantially similarly to the in-line dual-motor driven piston and dispensing system configuration described with respect to Figures 1–5. As shown in Figures 6A and 6B, the upper pipette housing 205 includes an electronic drive unit and is connected to the dispenser housing 252 by a housing nut 208. The dispenser housing contains substantially the same fluid displacement system as described above. The upper pipette housing 205 contains a large piston motor 225, a large volume piston 230, a motor connection element 220, and a small piston motor 210. The small piston motor 210 is mounted on a plunger connection element 264 which is connected to a large plunger element 260. The small piston motor 210 is mounted on a small volume piston 212, which is connected to a small plunger element 270 by a connector 271. Most of the small plunger element 270 and the large plunger element 260 are housed within the dispenser housing 252.

[0060] The large plunger element 260 moves within the large vacuum chamber 255. The large plunger element 260 includes a cylindrical bore or small vacuum chamber 265, within which the small plunger element 270 is slidably received, resulting in a nested plunger configuration. A set of O-rings 250, 262, 263, and 272 may be included to prevent air leakage between the vacuum chamber and the connection point. For example, the O-ring 262 at the bottom of the large plunger element 260 (see Figure 6D) prevents air leakage into the large vacuum chamber 255 when the large plunger element 260 is in a fully closed position or a "bottom-out" (or bottomed-out) position. The pipette device 200 includes both a small tip holder 245 and a large tip holder 248, to which the user can attach the desired disposable pipette tip by interference fit or restriction fit as described above.

[0061] Figures 6A and 6E show a rechargeable battery 280 housed within the upper housing 205. Such a rechargeable battery 280 within the upper housing 205 allows power to be supplied to the pipette device 200's piston motors 210, 225 without the need to connect the pipette device 200 to an external outlet or other power source. The user inputs the desired dispensing volume by turning / rotating the actuation element / volume control unit 215, or, in some embodiments, by inputting the desired volume via the interface of the LCD screen 295. In either design, feedback readouts are displayed via the LCD screen 295. The volume input is sent to the device control PCB 285, which electronically communicates with the device's motors and signals them.

[0062] The operating pipette device 200 functions substantially the same as the pipette device 100 shown in Figures 1 to 5. While in the large volume range (e.g., a volume range of approximately 50 μL to approximately 1000 μL or more), the user presses the actuarial element / volume control unit 215. This sends a signal to the large piston motor 210 via the instrument control PCB 285, causing the large volume piston 230 to move upward along with the motor connection element 220, the small piston motor 225, and the large plunger element 260. As the large plunger element 260 moves upward within the large vacuum chamber 255, the volume of the large vacuum chamber increases, creating the vacuum necessary to cause the corresponding air displacement into the fluid inlet 275, which in turn draws the corresponding volume of liquid into the pipette tip. Then, when the user presses the actuation element / volume control unit 215 again, the large plunger element 260 moves downward, dispensing liquid from the pipette tip. On the other hand, while in the small volume range (e.g., approximately 1 μL to approximately 100 μL), both the large plunger element 260 and the small plunger element 270 are "bottomed out" to the closed position. When the user presses the actuation element / volume control unit 215, a signal is sent to the small piston motor 225 via the instrument control PCB 285, causing the small volume piston 212 and the small plunger element 270 to move upward. As the small plunger element 270 moves upward within the small vacuum chamber 265, a vacuum is created necessary to cause the corresponding air displacement into the fluid inlet 275, and this air displacement draws the corresponding volume of liquid into the pipette tip. Then, when the user presses the operating element / volume control unit 215 again, the small plunger element 270 moves downward, and liquid is dispensed from the tip of the pipette.

[0063] Furthermore, the pipette device 200 includes a multi-stage spring-loaded tip ejector mechanism. This mechanism comprises an ejector element 235, a large tip ejector biasing spring 237, a large tip ejector sleeve 240, and a small tip ejector biasing spring 290. The function of the multi-stage spring-loaded tip ejector mechanism is described in detail above.

[0064] Figures 7–8D show alternative embodiments of the pipette device 300 of this disclosure, including a cantilever motor connection element 320. The cantilever motor connection element 320 allows for a more ergonomic and space-saving design. Rather than the in-line motor-driven piston design described above, the cantilever motor connection element 320 connects to the large-volume piston 330 and small-volume piston motor 310 of the large-volume piston motor 325 and the small-volume piston motor 310, resulting in an offset configuration within the pipette housing 305 (see Figure 7). The user inputs the desired volume by rotating the actuation element / volume control unit 315 as described above, and the value is displayed on the LCD screen 395. As in other embodiments, the LCD screen 395 includes a user interface for selecting the desired volume. When the user inputs a larger volume (e.g., approximately 50 μL to approximately 1000 μL or more), the volume input is transmitted to the instrument control PCB 385, which signals the large piston motor 325, causing the small piston motor 310 and the large plunger element 360 to move to the closed position. When the user presses the actuation element / volume control unit 315, the instrument control PCB 385 signals the large piston motor 325 to move the large volume piston 330, the cantilever motor connection element 320, the small piston motor 310, and the large plunger element 360 upward. As the large plunger element 360 moves upward from the closed position to the open position within the large vacuum chamber 355 (see Figures 8A and 8D), the resulting vacuum draws air into the fluid inlet 375, and a corresponding amount of liquid is drawn into the pipette tip attached to the tip holder 345, as described in detail above. Then, the user presses the operating element / volume control unit 315 again to move the large plunger element 360 downward to the closed position, thereby discharging the liquid from the tip of the pipette.

[0065] When a smaller volume (e.g., approximately 1 μL to 100 μL) is input by the user, this volume input is transmitted to the instrument control PCB 385, which sends a signal to the large piston motor 325, thereby moving the small piston motor 310 and the large plunger element 360 to the closed position. When the user presses the actuation element / volume control unit 315, the instrument control PCB 385 sends a signal to the small piston motor 310, which moves the small volume piston and small plunger element 370 upward from the closed position to the open position within the small vacuum chamber 365 (see Figures 8A and 8D). As the small plunger element 370 moves upward from the closed position to the open position within the small vacuum chamber 365, the liquid is drawn into the pipette tip attached to the tip holder 345, as detailed above. Next, when the user presses the operating element / volume control unit 315 again, the small plunger element 370 moves downward to the closed position, thereby discharging the liquid from the tip of the pipette.

[0066] The pipette device 300 includes a rechargeable battery 380, as well as a set of O-rings 372, 363, and 362 for preventing air leaks between the vacuum chamber and the plunger element.

[0067] Reference number 10: Pipette 12: Drive Section 14: Dispense section (or dispenser section) 15: Pipette Housing 16: Motor and piston assembly 18: Large plunger assembly 20: Actuating element (or actuate element) 25: Top surface (or upper surface) of the operating element 30: Ejector element (or removable element) 35: Bias spring (or bias spring) (large tip ejector) 40: Eject Sleeve 41: Upward ejection sleeve (or upper ejection sleeve) 42: Tapered portion of the ejection sleeve 43: Intermediate ejection sleeve 44: Downward ejection sleeve (or lower ejection sleeve) 45: Large tip ejector edge 46: Mechanical catch element 48: Large tip holder (or large tip holder) 49: Small tip holder (or small tip holder) 50: Fluid inlet / outlet (air) 51: Bias spring (or bias spring) (small tip ejector) 52: Dispenser Housing 53: Nut 54: O-ring (O-ring for ejector) 55: Large Vacuum Chamber 56: O-ring (large plunger) 60: Large plunger element 65: Small vacuum chamber 70: Small plunger element 75: Sheet (large plunger element) 80: Sheet (small plunger element) 85: Fluid passage (dispenser housing) 86: Fluid inlet (large vacuum chamber) 88: Fluid inlet (large plunger) 90: Bias spring (or bias spring) (for small plunger element) 92: Upper spring seat 95: Small volume piston 100: Connecting element (threaded element) 105: Piston Receiver 110: Small piston motor 115: Mounting element 120: Motor connector element 125: Large Piston Motor 130: Large volume piston 135: Small plunger end 140: O-ring (small plunger) 145: Large plunger end 155: Internal space or opening (small plunger / receptacle) 160: Motor Assembly Anchor 162: Screw hole 200: Pipette 205: Pipette Housing 208: Housing Nut 210: Small piston motor 212: Small volume piston 215: Actuating element / volume control unit 220: Motor connection element 225: Large Piston Motor 230: Large volume piston 235: Ejector element 237: Bias spring (or bias spring) (large tip ejector) 240: Large tip ejector sleeve 245: Small tip holder 248: Large tip holder / Small tip ejector 250: O-ring (small tip) 252: Dispenser Housing 255: Large Vacuum Chamber 260: Large plunger element 262: O-ring (large plunger) 263: O-ring (large vacuum chamber) 264: Large plunger connector 265: Small vacuum chamber 270: Small plunger element 271: (Small plunger) connector 272: O-ring (small vacuum chamber) 275: Fluid inlet 280: Rechargeable battery (or rechargeable battery) 285: Equipment control PCB 290: Bias spring (small tip ejector) 295: LCD screen (or LCD display) 300: Pipette 305: Pipette Housing 310: Small piston motor 312: Small volume piston 315: Actuating element / volume control unit 320: Cantilever motor connection element 325: Large Piston Motor 330: Large volume snapshot 345: Tip holder 355: Large Vacuum Chamber 360: Large plunger element 362: O-ring (large plunger element) 363: O-ring (large vacuum chamber) 365: Small Vacuum Chamber 370: Small plunger element 372: O-ring (small vacuum chamber) 375: Fluid inlet 380: Rechargeable battery (or rechargeable battery) 385: Equipment control PCB 395: LCD screen (or LCD display)

Claims

1. A multi-volume liquid dispenser, A long body comprising a pipette housing and a dispenser housing, and A motor assembly comprising a first motor and a second motor located within a pipette housing and controlled by a control system. It consists of having, The dispenser housing has an open end that allows air to be introduced into the dispenser housing and air to be discharged from the dispenser housing, and the dispenser housing is configured to which a syringe or tip is attached. The control system is controlled via a user interface for operating the multi-volume liquid dispenser. The first motor is operablely connected to the large plunger and operates the large plunger in a large cylindrical vacuum chamber between a closed position and an open position, the movement of the large plunger to the open position causes a displacement of air into the large cylindrical vacuum chamber that is approximately equal to the volume of the first liquid drawn in by the multi-volume liquid dispenser. The second motor is operablely connected to the small plunger and operates the small plunger between a closed and open position in a small cylindrical vacuum chamber located within the large plunger, the movement of the small plunger to the open position causes a displacement of air into the small cylindrical vacuum chamber that is approximately equal to the volume of the second liquid drawn in by the multi-volume liquid dispenser. A multi-volume liquid dispenser in which the large plunger is in the closed position when the small plunger moves to the open position, and the small plunger is in the closed position when the large plunger moves to the open position.

2. The multi-volume liquid dispenser according to claim 1, wherein the first motor is further configured to operate a large plunger from an open position to a closed position so that a first volume of liquid is dispensed from the multi-volume liquid dispenser, and the second motor is further configured to operate a small plunger from an open position to a closed position so that a second volume of liquid is dispensed from the multi-volume liquid dispenser.

3. A multi-volume liquid dispenser according to claim 1 or claim 2, wherein the range of the first liquid volume and the range of the second liquid volume overlap each other.

4. A multi-volume liquid dispenser according to claim 1, claim 2, or claim 3, wherein the first liquid volume is in the range of approximately 10 μL to approximately 1500 μL, and the second liquid volume is in the range of approximately 0.1 μL to approximately 200 μL.

5. The multi-volume liquid dispenser according to any one of claims 1 to 4, wherein the large plunger has a cross-sectional diameter larger than the cross-sectional diameter of the small plunger.

6. The multi-volume liquid dispenser according to claim 5, wherein the ratio of the cross-sectional diameter of the small plunger to the cross-sectional diameter of the large plunger is approximately 1:1.1 to approximately 1:

40.

7. A multi-volume liquid dispenser according to any one of claims 1 to 6, wherein the first motor, the second motor, or both the first motor and the second motor are selected from the group consisting of a servo motor, a stepper motor, and a linear actuator motor.

8. A multi-volume liquid dispenser according to any one of claims 1 to 7, wherein the syringe or tip is attached to the dispenser housing by an interference fit.

9. A multi-volume liquid dispenser according to any one of claims 1 to 8, wherein the dispenser housing comprises a first tip holder and a second tip holder, and the peripheral surface of the first tip holder is larger than the peripheral surface of the second tip holder.

10. The multi-volume liquid dispenser according to claim 9, further comprising a multi-stage spring-loaded ejector mechanism.

11. The device further comprises an ejector assembly positioned on a long body, the ejector assembly comprising an upper ejection portion biased upward and equipped with a large tip ejector edge, and a lower ejection portion biased upward, the first tip holder equipped with a small tip ejector edge, the upper ejection portion moving downward to move to a first or second position, During movement to the first position, when a first force is applied to the eject element, the large tip eject edge contacts the first tip holder portion, and the tip is ejected. The multi-volume liquid dispenser according to claim 10, wherein the small tip eject edge contacts the second tip holder portion when a second force is applied to the eject element during the movement of the lower ejection portion to the second position, and the tip is ejected.

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