Dynamic broad volumetric 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 the benefit of 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 meteringly supply) liquid over a wide range of volumes. In particular, the present specification discloses an electronic pipette comprising a motor - driven piston system including a set of nested plunger elements (or nested plunger elements) provided with separate displacement chambers 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 is used 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. An electronic pipette has a control system and an associated user interface, and such a control system and associated user interface can, for example, set the volume and other required pipette functions and provide commands for performing operations. When 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 of less than about 1 mL, typically in the range of about 0.5 μL to about 1 mL. However, as will be understood by those skilled in the art, current pipette technology does not enable 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 the entire range without sacrificing at least accuracy and precision. In typical wet-lab operations that require the dispensing of liquid volumes in such a range, the use of three to four different pipette devices (each optimized for accurate and precise aspiration / dispensing of a subset of such volume ranges) is required. For example, a researcher would typically use a 20 μL pipette to dispense fluid volumes in the range of about 2 μL to about 20 μL, a 200 μL pipette to dispense fluid volumes in the range of about 20 μL to about 200 μL, and a 1000 μL pipette to dispense fluid volumes in the range of about 100 μL to about 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 liquid over a wider range of liquid volumes without sacrificing accuracy and / or precision. SUMMARY OF THE INVENTION

[0006] Disclosed herein is a multi - volume pipette device (or pipetting device) capable of accurately and precisely aspirating (or drawing in, aspirate) and dispensing (or supplying, dispensing, dosing, or aliquoting, dispense) liquid over a wide volume range. In particular, the device disclosed herein preferably employs nested plunger elements (or plunger elements nested within one another) that operate within different (or distinct) vacuum chambers for air displacement (or pushing out, moving, displacing, or replacing, displacement), thereby causing aspiration of substantially equal volumes of liquid. By virtue of the novel nested plunger design, the device is capable of seamless and rapid dynamic switching from a low volume range (or small volume range) to a high volume range (or large volume range).

[0007] In one aspect, the present invention is a pipette including a body and a fluid transfer assembly, the body having 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 having a first vacuum chamber, a first plunger element, a second vacuum chamber, and a second plunger element. In such an aspect, the first vacuum chamber has a first bore with a first fluid inlet. The first plunger element is positionable to slide within the first bore and is movable 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 has a second bore within the first plunger element and has a second fluid inlet. The second plunger element is positionable to slide within the second bore and is movable 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 open end of the body. The design of such a pipette also features an electronic drive unit for operating the first plunger element and the second plunger element. The electronic drive unit is operably connected to the first plunger element and includes a first motor configured to operate the first plunger element between the closed position and the open position within the first bore, and is operably connected to the second plunger element and includes a second motor configured to operate the second plunger element between the closed position and the open position within the second bore. The first motor and the second motor are controlled by a control system, and the control system is controlled via a user interface for operating the pipette.When the first motor causes the first plunger element to move to the open position by a distance such that a first liquid volume is aspirated by the pipette device in an amount substantially equal to the fluid volume displaced (or displaced) by the movement of the first plunger element, the second plunger element is in the closed position. Also, when the second motor causes the second plunger element to move to the open position by a distance such that a second liquid volume is aspirated by the pipette device in an amount substantially equal to the fluid volume displaced (or displaced) by the movement of the second plunger element, the first plunger element is in the closed position. Additionally, by the movement of the first plunger element from the open position to the closed position, the first liquid volume is accurately dispensed from the pipette, or by the movement of the second plunger element from the open position to the closed position, the second liquid volume is accurately dispensed from the pipette. In some embodiments, the fluid displaced (or displaced) is air.

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

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

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

[0011] Another aspect of the present invention is characterized by a method for adjusting the volume (or volumetric capacity, volume capacity, volume throughput, or volume capacity) of a pipette, the method comprising receiving, at a control module, a requested volume requested by a user, determining, at the control module, a volume range within which the received requested volume fits, and controlling, by the control module, a first motor or a second motor. In such an exemplary method, the first motor moves the first plunger element from a closed position to an open position within the first vacuum chamber by a distance such that a first liquid volume aspirated by the pipette device is defined by an amount substantially equal to the fluid volume displaced (or displaced) 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 within the second vacuum chamber by a distance such that a second liquid volume aspirated by the pipette device is defined by an amount substantially equal to the fluid volume displaced (or displaced) by the movement of the second plunger element. In such a method, the second vacuum chamber is disposed within the first plunger element and the second plunger element is received slidably within the second vacuum chamber of the first plunger element. Such a method may include controlling the first motor or the second motor, the first motor moving the first plunger element from the open position to the closed position within the first vacuum chamber to dispense the first liquid volume, or controlling the first motor or the second motor such that the second motor moves the second plunger element from the open position to the closed position within the second vacuum chamber to dispense the second liquid volume.

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

[0013] In another aspect of the above method, the first motor is operably connected to the first plunger element by a first piston, and the second motor is operably connected to the second plunger element by a second piston. In yet another aspect, the first plunger element is cylindrical and has a first cross-sectional diameter (e.g., in the range of about 3 mm to about 20 mm), the second plunger element is cylindrical and has a second cross-sectional diameter (e.g., in the range of about 0.5 mm to about 5 mm), and the first cross-sectional diameter is larger than the second cross-sectional diameter. In some aspects, 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 aspects, 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.

[0014] Yet another gist of the present invention features a multi-volume liquid dispenser, which includes a long body having a pipette housing and a dispenser housing, and a motor assembly disposed within the pipette housing and having a first motor and a second motor controlled by a control system. and has a dispenser housing having an open end that allows air to be introduced into and discharged from the dispenser housing, and the dispenser housing is configured to have a syringe or a tip (or tip member) attached thereto, and the control system is controlled via a user interface for operating the multi-volume liquid dispenser. In such a multi-volume liquid dispenser of a specific design, a first motor is operably connected to a large plunger and is configured to actuate the large plunger within a large cylindrical vacuum chamber between a closed position and an open position, and movement of the large plunger to the open position causes displacement (or pushing out) of air into the large cylindrical vacuum chamber that is approximately equal to a first liquid volume aspirated by the multi-volume liquid dispenser. A second motor is operably connected to a small plunger and is configured to actuate the small plunger within a small cylindrical vacuum chamber disposed within the large plunger between a closed position and an open position, and movement of the small plunger to the open position causes displacement (or pushing out) of air into the small cylindrical vacuum chamber that is approximately equal to a second liquid volume aspirated by the multi-volume liquid dispenser. Further, 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. And in some embodiments, the first motor is further configured to actuate the large plunger from the open position to the closed position to dispense a first liquid volume from the multi-volume liquid dispenser, and the second motor is further configured to actuate the small plunger from the open position to the closed position to dispense a second liquid volume from the multi-volume liquid dispenser.

[0015] In one aspect, the first liquid volume ranges from about 10 μL to about 1500 μL, and the second liquid volume ranges from about 0.1 μL to about 200 μL. Further, the large plunger has a cross-sectional diameter that is larger than the cross-sectional diameter of 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 from about 1: about 1.1 to about 1: about 40. Similar to the above-described design, the plunger is moved by a pair of motors (or a pair of motors or a pair of motors), and such motors can be selected from the group consisting of any number of suitable motors including, but not limited to, servo motors, stepper motors, or linear actuator motors.

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

[0017] In some embodiments, the multi-volume liquid dispenser includes a multi-tiered spring-loaded ejector mechanism (or an ejector mechanism with multiple stepped or layered spring loads). In such embodiments, the multi-tiered spring-loaded ejector mechanism may include an ejection element (or ejector element or eject unit) having an upper ejection portion (or upper ejector portion or upper eject unit) biased to an upper position by a first biasing element and a lower ejection portion (or lower ejector portion or lower eject unit) biased to an upper position by a second biasing element. In such a design, when a user applies a first force to the multi-tiered 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. Alternatively, when the user applies a second force to the multi-tiered 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 reference to the drawings and the following detailed description and illustrative examples.

Brief Description of the Drawings

[0019]

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Best Mode for Carrying Out the Invention

[0020] (Detailed Description of the Invention) The pipette device described herein functions in combination such that multiple (or plural or numerous) volume air displacement chambers (i.e., vacuum chambers) are provided, and has two or more motor-driven plunger elements, and can transfer a large (or wide) range of liquid volumes by a novel dispenser design. In particular, each vacuum chamber can be optimized for precise displacement (or pushing out, moving or displacement) of a fluid such as air over different volume ranges. When a vacuum is formed within the chamber, fluid (e.g., air) enters the chamber, causing the pipette to aspirate a substantially equal volume of liquid. Further, each plunger element is driven by an individual (or separate) motor, thereby enabling rapid and dynamic switching from one vacuum chamber to the next so that a user can perform liquid pipetting seamlessly over a wide range of volumes. In such a manner, the pipette device can aspirate and dispense liquid over a wider range of volumes compared to currently available devices. Multiple plunger elements (or plural or numerous plunger elements) are included within the device housing, and a vacuum is formed by the physical movement of the plungers within the housing. In a preferred embodiment, the plunger is at least partially included within a hole (or bore) or hollow space within the housing or casing in the dispenser section of the device. As the plunger element moves within the hollow space or bore of the vacuum chamber, fluid (e.g., air) is drawn into or out of the chamber, thereby aspirating or dispensing a corresponding volume of liquid from the pipette tip, respectively. The plunger may be made of a hard material (or rigid material) such as a plastic material or a metal material. Further, although other shapes are possible for the plunger, it preferably has a cylindrical shape.As described below, in a preferred embodiment of the present invention, at least two plunger elements are suitable for use, and the plungers are cylindrical and arranged in a nested configuration with respect to each other.

[0021] Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Standard techniques are used unless otherwise specified. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and example matters are given by way of illustration only and are not intended to limit the invention. All publications, patents, and other documents mentioned herein are hereby incorporated by reference in their entirety.

[0022] The singular forms “a,” “an,” and “the” as used herein include plural referents unless the context clearly dictates otherwise.

[0023] The term “about” indicates the numerical variability of a measurement due to the typical error rates of the device used to obtain such a measurement with respect to the numerical value of the measurement (e.g., diameter, area, length, volume, etc.).

[0024] As used herein, terms such as "approximately equivalent" refer to the volume of fluid displaced (or pushed aside, moved or displaced) by the device as compared to the volume of liquid aspirated by the device, meaning that the volume of fluid (e.g., air) displaced by the movement of a plunger element within a vacuum chamber is not exactly equal to the volume of liquid aspirated into a tip attached to the end of the device due to the difference between the density of the fluid and the density of the liquid. The device design is calibrated (or adjusted) taking such factors into account to be within an acceptable range for one of ordinary skill in the art.

[0025] "Interference fit" or "friction fit" (or friction mating or friction fitting) are used interchangeably herein and refer to the attachment (or fastening) between two parts achieved by friction after the parts are pushed together.

[0026] Designations such as "up", "down", "upward", "downward", "horizontal" and "vertical" as used herein refer to the orientation / direction of the pipette device, referring to the orientation / direction in which the pipette housing has the actuator member or push button at the top and the dispense end at the bottom (see, e.g., FIG. 1A). In such an orientation, the pipette tip fixed or attached to the dispense end of the dispenser housing can be directed towards a vessel positioned thereunder for aspiration or delivery of liquid.

[0027] Figures 1A - 4 show aspects of a pipette device (or pipetting device) of the present invention. The pipette device 10 generally has an elongated or rod - shaped form with a top - side drive section 12 that includes all of a drive unit and associated elements enclosed within a pipette housing 15. The pipette device 10 also generally includes a bottom - side fluid displacement (or fluid displacement, fluid movement or fluid displacement) - fluid dispense section 14, such section including a dispenser housing 52 that includes at least a portion of plunger elements 60, 70. A cylindrical push - button - shaped actuator element (or actuation element) 20 projects upwardly from the pipetting housing 15 of the drive section 12. The actuator element 20 is axially movable within the pipette housing 15 and is used by a user (or operator) to effect fluid aspiration or fluid dispense (or fluid distribution or dispensing) by the pipette device.

[0028] The bottom or dispensing end (or dispensing tip or pipetting tip) of the pipette device described herein includes at least one holder or seat element (or chair element or pedestal element, seat element), to which the pipette tip for liquid aspiration is attached (or fastened or fixed). The housing or casing of the dispensing end preferably includes two or more seat portions or holder portions, with one portion of the dispensing housing configured to receive a pipette tip of a certain volume and the other portion of the dispensing housing configured to receive 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 or volume) ranging from about 10 μL to about 1500 μL, and preferably the pipette tip is capable of aspirating liquid in a volume ranging from about 50 μL to about 1000 μL. In such an embodiment, the dispenser housing includes a second holder portion for a pipette tip capable of aspirating liquid in a volume ranging from about 0.50 μL to about 200 μL. Thus, the shape / design of the dispensing section is suitable for accommodating different sizes of pipette points / pipette tips.

[0029] Figures 1A and 2 show an exemplary dispenser housing 52 configured to accommodate a large pipette tip capable of aspirating a liquid volume in the range of about 10 μL to about 1500 μL (e.g., about 10 μL, about 15 μL, about 20 μL, about 25 μL, about 30 μL, 40 μL, about 50 μL, about 60 μL, about 70 μL, about 80 μL, about 90 μL, about 100 μL, about 110 μL, about 120 μL, about 130 μL, about 140 μL, about 150 μL, about 160 μL, about 170 μL, about 180 μL, about 190 μL, about 200 μL, about 210 μL, about 220 μL, about 230 μL, about 240 μL, about 250 μL, about 260 μL, about 270 μL, about 280 μL, about 290 μL, about 300 μL, about 350 μL, about 400 μL, about 450 μL, about 500 μL, about 550 μL, about 600 μL, about 650 μL, about 700 μL, about 750 μL, about 800 μL, about 850 μL, about 900 μL, about 950 μL, about 1000 μL, about 1100 μL, about 1200 μL, about 1300 μL, about 1400 μL, or about 1500 μL) and a small pipette tip capable of aspirating a liquid volume in the range of about 0.1 μL to about 200 μL (e.g., about 0.1 μL, about 0.2 μL, about 0.3 μL, about 0.4 μL, about 0.5 μL, about 1.0 μL, about 1.5 μL, about 2.0 μL, about 2.5 μL, about 3.0 μL, about 4.5 μL, about 5.0 μL, about 10 μL, about 15 μL, about 20 μL, about 25 μL, about 30 μL, about 40 μL, about 50 μL, about 60 μL, about 70 μL, about 80 μL, about 90 μL, about 100 μL, about 110 μL, about 120 μL, about 130 μL, about 140 μL, about 150 μL, about 160 μL, about 170 μL, about 180 μL, about 190 μL, about 200 μL). In some embodiments, the range of the first liquid volume is about 50 μL to about 1000 μL, and the range of the second liquid volume is about 0.5 μL to about 200 μL. Accordingly, 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. This stepped structure has an outer circumference (or outer periphery) of the device at the large tip holder portion that is wider (or larger) than the outer circumference (or outer periphery) at the small tip holder portion.Accordingly, the stepwise design enables fitting or fastening of tips of different sizes due to interference fit or friction fit, and by utilizing the circular force of the pipette tip against the tip holder portion (or distal tip holder portion) of the pipette device, the pipette tip is fixed to the dispenser housing 52 and is fixed to either the large tip holder 58 or the small tip holder 59. Accordingly, the pipette device 10 can aspirate and dispense liquid in a volume range of about 0.1 μL to about 1500 μL (e.g., about 0.1 μL, about 0.2 μL, about 0.3 μL, about 0.4 μL, about 0.5 μL, about 1.0 μL, about 1.5 μL, about 2.0 μL, about 2.5 μL, about 3.0 μL, about 4.5 μL, about 5.0 μL, about 10 μL, about 15 μL, about 20 μL, about 25 μL, about 30 μL, about 40 μL, about 50 μL, about 60 μL, about 70 μL, about 80 μL, about 90 μL, about 100 μL, about 110 μL, about 120 μL, about 130 μL, about 140 μL, about 150 μL, about 160 μL, about 170 μL, about 180 μL, about 190 μL, about 200 μL, about 210 μL, about 220 μL, about 230 μL, about 240 μL, about 250 μL, about 260 μL, about 270 μL, about 280 μL, about 290 μL, about 300 μL, about 350 μL, about 400 μL, about 450 μL, about 500 μL, about 550 μL, about 600 μL, about 650 μL, about 700 μL, about 750 μL, about 800 μL, about 850 μL, about 900 μL, about 950 μL, about 1000 μL, about 1100 μL, about 1200 μL, about 1300 μL, about 1400 μL, or about 1500 μL). In certain embodiments, the pipette device 10 can aspirate and dispense liquid in a volume range of about 0.5 μL to about 1000 μL. As will be described in more detail below, the device of the present invention can accurately and precisely aspirate and dispense liquids of such a wide range of volumes by virtue of its dual-motor-driven (or two-motor-driven) piston and plunger element design.

[0030] As will be understood by those skilled in the art, typical pipettes utilize disposable pipette tips and must quickly remove and replace the pipette tip during the handling of different liquid samples to prevent contamination or unwanted liquid mixing. Accordingly, the pipette device of the present disclosure may be a device having a design with an ejector mechanism (or discharge mechanism) for quickly and easily removing the pipette tip without the user having to touch the tip itself.

[0031] An ejector mechanism suitable for use in the pipette device of the present invention includes the multi-stage spring-loaded ejector shown in FIGS. 1A and 1B, which is a single ejector assembly (or discharge assembly or removal assembly) that can eject (or discharge or remove) tip portions of different sizes from different attachment points of the dispensing portion of the pipette. In the embodiments shown in FIGS. 1A and 1B, the pipette device 10 has an ejector element 30 (e.g., a push button) connected to an ejector sleeve (or ejection sleeve, discharge sleeve or removal sleeve) 40. A suitable embodiment of the ejector sleeve 40 may include an upper ejector sleeve (or upper ejection sleeve) 41 that extends for approximately the length of the pipette housing 15. The upper ejector sleeve 41 has a tapered portion 42 (or is tapered) towards an intermediate ejector sleeve 43 after the pipette housing point, and the intermediate ejector sleeve 43 includes a mechanical catch element 46. The upper ejector sleeve 41 is spring-loaded at the top by a biasing spring (or bias spring) 35, and while the ejector assembly is held in the highest mechanical position, the user can mechanically move the sleeve downward and downward against the biasing spring 35. Moving the ejector sleeve 40 downward and downward causes the mechanical catch element 46 to contact a lower ejector sleeve (or lower ejection sleeve) 44.

[0032] The lower ejector sleeve 44 is also spring-loaded by the biasing spring 51 and held in its uppermost position. When the large tip is present in the large tip holder 48, the upper ejector sleeve 40 is moved downward and downward until it reaches a point where it increases the tension from the biasing spring 51 on the lower ejector sleeve 44. In such a range of movement (or in the range in which the upper ejector sleeve moves in this way), pressure is exerted from the large tip ejector edge 45 and the large tip is removed from the large tip holder 48.

[0033] When there is no large tip, the user depresses the ejector element 30 until the mechanical catch element 46 engages the lower ejector sleeve 44. And when the user continues to depress at such a point (or from such a point), the engagement (or engagement) of the biasing spring 51 of the lower ejector sleeve 44 is brought about, and the lower ejector sleeve 44 will move downward, and the small tip is released from the small tip holder 49. In such a design aspect, where the large tip holder also doubles as the small tip ejector edge, an O-ring 54 is included to ensure that the large tip holder maintains airtightness.

[0034] In another aspect, the multi-stage spring load ejector of the pipette device includes two separate ejector elements (e.g., buttons), and depending on whether the large tip is attached to the large tip holder or the small tip is attached to the small tip holder, the user presses either the large tip ejector element or the small tip ejector element. 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 aspects, although at different distances corresponding to the large tip holder and the small tip holder, both the large tip ejector element and the small tip ejector element may be configured to move the same eject sleeve. In other aspects, 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 the present disclosure is capable of aspirating and dispensing a wide range of liquid volumes, largely due to its motor-driven nested plunger element design (a design in which at least one plunger element is slidably received within another plunger element). Movement of each plunger element within the corresponding vacuum chamber creates a "vacuum within the chamber" that causes an inflow of fluid (e.g., air). Such fluid displacement (or fluid displacement, fluid movement, or fluid displacement) aids in aspirating a substantially equal volume of liquid into the attached pipette tip. In this way, each plunger element enables the addition of a vacuum chamber to the device. And each vacuum chamber has a different volume (or volume capacity) with respect to the inflow of fluid (e.g., air). In a preferred embodiment, movement of the plunger element within its vacuum chamber creates a vacuum that causes displacement of air. In other words, air enters into the vacuum chamber. Such displacement of air causes a corresponding volume of liquid to be aspirated into the tip attached to the end of the device.

[0036] Furthermore, an arrangement (or disposition) of nested plunger elements with decreasing cross-sectional area results in a vacuum chamber with a reduced volume. For example, one plunger element includes an internal space or bore in which another, smaller plunger element is slidably received or positioned. Thus, when such a relatively small plunger element (or smaller plunger element) moves up and down within a relatively large plunger element (or larger plunger element), another vacuum chamber is provided, albeit with a relatively small volume. Therefore, the pipette device described herein enables rapid and dynamic switching from one vacuum chamber to another by operating different plunger elements, and is a device that can accurately and precisely dispense a wider range, larger range of liquid volume amounts compared to currently available devices on the market. The pipette device disclosed herein can have any number of nested plunger elements and vacuum chambers, where the pipette device in the non-limiting exemplary embodiments shown in FIGS. 1A-8D has 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, with one of the plunger elements being slidably received 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 a receptacle or bore of the large plunger element, such that another relatively small vacuum chamber (or a smaller vacuum chamber) is provided (see, for example, FIGS. 2-4). 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 the amount of fluid (e.g., air) displaced by the vacuum chamber. Ultimately, by the displacement of the fluid, a substantially equal volume amount of liquid is drawn into the pipette tip. The movement of the plunger elements is preferably controlled by a set of motor-driven pistons housed within the drive section of the device.

[0038] As described above, the plunger element preferably has a cylindrical shape with different cross-sectional diameters so as to provide a nested plunger design with separate (or distinguishable) vacuum chambers having different volumes. For example, in one particular embodiment, the cross-sectional diameter of the large plunger element can typically be from about 3 mm to about 20 mm, such as 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 from about 5 mm to about 15 mm, more preferably from about 6 mm to about 10 mm. For example, in one embodiment, the cross-sectional diameter of the large plunger element is from about 7 mm to about 8 mm. For the small plunger element, the cross-sectional diameter can be from about 0.5 mm to about 5 mm, such as 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 that of the large plunger element, on the condition that a nested arrangement is enabled). In some embodiments, the cross-sectional diameter of the small plunger element is between about 1 mm and about 3 mm. For example, in one particular embodiment, the cross-sectional diameter of the small plunger element is from about 1.4 mm to about 1.7 mm.

[0039] The nested plunger arrangement suitable for use in the present 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 expulsion, fluid movement, or fluid displacement) in a handheld (or portable type or hand-held type) pipette. In some embodiments, the ratio of the diameter of the small plunger element to the diameter of the large plunger element is from 1:1.1 to 1:40, such as 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, 1:40. In other aspects, the ratio of the diameter of the small plunger element to the diameter of the large plunger element is from 1:2 to 1:10. For example, in one particular aspect, such ratio is 1:5.

[0040] Next, the configuration and function of the nested plunger will be described in more detail. As shown in FIGS. 2, 3, 4A, and 4B, the drive section 12 includes a motor assembly 16 housed in the pipette housing 15. The motor assembly 16 is connected to the large plunger assembly 18 via an attachment element 115. The attachment 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, adhesives, etc. The large plunger element 60 is attached to the attachment element 115 and is partially disposed within the dispenser housing 52. The dispenser housing 52 includes a hole or fluid passage 85 passing through its center and an inlet 50 for receiving a fluid such as a liquid or a gas (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] Shown in FIG. 2 is 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 be movable along this vertical axis A. The large plunger element 60 is capable of moving or operating 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 contacts the sheet 75 inside the dispenser housing 52 and at the bottom of the large vacuum chamber 55. In the embodiments shown in FIGS. 2, 4A, and 4B, an O-ring 56 may be provided concentrically within the bottom of the large plunger element 60 to ensure that the seal is air tight. In the open position, the large plunger element 60 will move towards the top of its axis of movement. In the open position, the large plunger element 60 will move away from the sheet 75, thereby increasing the volume (or capacity) of the large vacuum chamber 55. When the large plunger element 60 is fully in the open position and at the top of its axis of movement, the large vacuum chamber 55 is at its maximum volume (or capacity). When the large plunger element 60 is in the open position, air can be displaced from the external environment into the large vacuum chamber 55 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 FIGS. 2, 4A, and 4B). In such an embodiment, the small plunger element 70 and the large plunger element 60 are provided concentrically. The small plunger element 70 is slidably received together with the internal space or passage 155 of the large plunger element 60, and a small vacuum chamber 65 is formed by the movement of the small plunger element 70 along the vertical axis A within the large plunger element 60. Thus, the small plunger element 70 necessarily has a cross-sectional area smaller than that of the large plunger element 60. In such an embodiment, the small plunger element 70 is typically solid (i.e., it does not have an internal fluid passage). However, as an embodiment having three or more vacuum chambers, the small plunger element 70 may further have an internal space for slidably receiving 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 movement axis (i.e., the opening 88 of the large plunger element 60). Thus, the end 135 of the small plunger element 70 will contact the sheet 80 inside the large plunger element 60 and at the bottom of the small vacuum chamber 65. Thus, displaced air cannot enter the small vacuum chamber 65. In the open position, the small plunger element 70 will move towards the top of its movement axis. In the open position, the small plunger element 70 will move away from the sheet 80, thereby increasing the volume of the small vacuum chamber 65. Thus, 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. Further, by using the biasing spring 90, the small plunger element 70 can be biased towards the open position. When the small plunger element 70 is fully in the open position and at the top of its movement axis, the small vacuum chamber 65 reaches 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 fluids such as air cannot enter 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, preventing 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, preventing the displaced air from moving into 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 the inlets 86, 88 and into the small vacuum chamber 65 disposed 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 the airtightness of the air passage of the small plunger when the large plunger is in the "closed" position.

[0046] Although a manually actuated design is conceivable, the preferred design of this pipette device actuates the plunger element using an electronic motor drive system. In particular, the device may have a separate electric motor configured to actuate each plunger element. In a preferred embodiment, the pipette device has a dual motor for actuating each of two nested plunger elements. The motor responds to a control system operated by the user via an interface. In some embodiments, the plunger element is directly connected to the motor. In other embodiments, each motor actuates a piston connected to the plunger element. Suitable motors include, but are not necessarily limited to, servo motors, stepper motors, and linear actuator motors. In certain embodiments, the plunger element is 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 a different type of motor.

[0047] Figures 2 and 3 show aspects of the present invention that utilize a dual-motor-driven piston for the operation of the plunger element. As shown in Figures 2 and 3, the small plunger element 70 is connected to a small-volume piston (or small-body piston) 95. The small-volume piston 95 is connected to a small piston motor 110 by a piston receiver 105 via a connection element 100 (e.g., via a screw combination or fitting). The small piston 95, the connection element 100, and the small plunger element 70 are operably movable along axis A in accordance with the metering of the small piston motor 110. The small piston motor 110 is connected to a large-volume piston (or large-body 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 operates in accordance with the metering of the large piston motor 125.

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

[0049] The operation of the pipette device is shown in FIGS. 5A - 5D. FIGS. 5A and 5B show the aspiration and dispensing of a large volume of liquid (e.g., from about 50 μL to about 1000 μL). When performing a large volume dispense, the user can attach a large pipette tip (e.g., a large pipette tip that dispenses a volume in the range of about 50 μL to about 1000 μL) to the end of the dispenser housing using the interference fit described above. When operating the device for large volume aspiration, 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 sheet 80 within the large vacuum chamber 55. The O - ring 140 ensures a gas - tight 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 FIG. 5A, the large plunger element 60 is in contact with the sheet 75 of the large vacuum chamber 55. Thus, the large plunger element 60 is also "bottomed out". In other words, both plunger elements can be said to be in the closed position. When both plunger elements are in the closed position, no air is displaced into either of the vacuum chambers 55, 65 from the external environment.

[0050] The user inputs the desired dispense volume via an interface consisting of a knob and / or buttons, and feedback is provided via an LCD screen (or LCD display). For example, as would be understood by one of ordinary skill in the art, the actuator element 20 may be configured for volume adjustment by rotation by the user using the feedback provided via the LCD screen. Such input is transmitted to a controller printed circuit board (PCB) within the pipette head connected to the motor via a power and communication cable. The PCB is programmed to store the operating range of each motor, such as a small volume range of the motor controlling the small motor and a large volume range of the motor controlling the large plunger. When the volume in the 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 a large volume range), when the user presses the button on the top surface 25 of the pipette, a signal is sent to the large motor, causing the piston to move to a position where it can draw an appropriate volume of liquid. Then, the large piston motor 125 moves the large volume piston 130 upward. When 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. When the large plunger 60 moves upward along axis A away from the seat 75 in the large vacuum chamber 55, the volume of the large vacuum chamber 55 increases, thereby generating a vacuum, which causes a corresponding displacement (or displacement, movement, replacement, or displacement) of air through the fluid inlet 50. The air rises through the fluid passage 85 in the dispenser housing 52 and enters the large vacuum chamber 55 through the fluid inlet 86. As a result, a corresponding volume of liquid is sucked 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. When the large plunger element 60 moves downward, the displaced air is displaced so as to be returned from the fluid inlet 50, and the liquid is dispensed from the pipette tip.

[0052] In a specific 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 in the large plunger element 60. Therefore, the 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 the displaced air from leaking into the small vacuum chamber.

[0053] In some embodiments, it is desirable to eject the pipette tip after dispensing fluid and replace the tip with a new one. The pipette device described herein can include an ejection mechanism, such as the multi-stage spring-loaded ejector mechanism shown in FIG. 1B. In this particular embodiment, when the ejector element 30 is depressed by the user, the mechanical catch element 46 contacts the lower ejector sleeve 44, causing the ejector sleeve 40 to move downward. If a large tip is present in the large tip holder 48, the upper ejector sleeve 40 is moved downward until the tension from the biasing spring 51 resisting the lower ejector sleeve 44 causes pressure from the large tip eject edge 45 to reach the point of contact 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 a downward force to attach the pipette tip to the pipette device by an interference fit or friction fit to effect replacement of the pipette tip. In some embodiments, it may be desirable for the user to reduce the dispense volume by having a smaller tip (e.g., a smaller tip configured for a dispense volume in the range of about 1 μL to about 200 μL) retained (or fixed) at the end of the dispenser housing.

[0055] Figures 5C and 5D show the aspiration and dispensing of a small volume of liquid (e.g., from about 1 μL to about 200 μL of liquid). 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 inserts the end of the small pipette tip into the liquid to be aspirated. The device can be switched from a large volume range to a small volume range via the user interface. In a preferred embodiment, since the resting position of the pipette device is the same whether the pipette device is in the large volume mode or the small volume mode, the pipette device does not include a physical switch. Thus, in a preferred embodiment, when the user selects a volume amount in the small volume range, the firmware is instructed to move only the small motor / plunger mechanism. Conversely, when a volume amount in the large volume range is selected, the large motor and plunger engage. Thus, in a preferred embodiment, such a process is seamless for the user. In some embodiments, the interface associated with the control system includes the option for one or more preset volumes to be programmed by the user so that the user can quickly switch between the preset volumes.

[0056] Once a desired volume within the small volume range is set, the user presses the top surface 25 of the actuating element 20. This sends a signal to the small piston motor 110, causing the small volume piston 95 to move upward to a position where it draws in the appropriate volume of liquid specified by the user. As shown in FIG. 5D, when the small volume piston 130 moves upward, the small plunger element 70 moves upward away from the seat 80 of the small vacuum chamber 65 along the axis A. Thus, the small plunger element 70 will transition from the closed position to the open position. As 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 corresponding displacement of air into the small vacuum chamber 65 through the fluid inlet 88 of the large plunger element 60 so as to pass through the fluid inlet 50. As a result, a substantially equal volume of liquid is drawn 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. Since the small plunger element 70 moves downward against the biasing spring 90, the displaced air is displaced so as to be returned from the fluid inlet 50, and the fluid is dispensed from the pipette tip.

[0057] To eject the small pipette tip, the user depresses the ejector element 30 until the mechanical catch element 46 of the intermediate eject sleeve 43 engages the lower eject sleeve 44. At such a point, the user continues the downward pressure, engaging the biasing spring 51 (or causing the engagement of the biasing spring). Then, when the lower eject sleeve 44 is moved downward, the small tip will be released (or liberated) 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 and its end 145 is in contact with the sheet 75 on the floor of the large vacuum chamber 55. An O-ring 56 is provided concentrically inside the bottom of the large plunger to keep the small volume chamber airtight. Therefore, the "displaced air" flowing upward through the passage 85 does not leak into the large vacuum chamber 55 and directly flows into the small vacuum chamber 65 through the fluid inlets 86 and 88.

[0059] Figures 6A - 6E show another embodiment of a pipette device with an LCD screen and a rechargeable battery. The pipette device 200 includes the inline dual-motor driven piston and dispensing system configuration described above with respect to Figures 1 - 5 and functions substantially the same. 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. Inside the dispenser housing, a fluid displacement system substantially the same as the above is provided. Inside the upper pipette housing 205, a large piston motor 225, a large volume piston 230, a motor connection element 220, and a small piston motor 210 are provided. The small piston motor 210 is attached to a plunger connection element 264 that is connected to the large plunger element 260. The small piston motor 210 is attached to a small volume piston 212, and the small volume piston 212 is connected to the small plunger element 270 by a connector 271. Most of the small plunger element 270 and the large plunger element 260 are housed inside 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 hole 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 can be included, thereby preventing air leakage between the vacuum chamber and the connection points. For example, the O - ring 262 (see FIG. 6D) at the bottom of the large plunger element 260 prevents air leakage into the large vacuum chamber 255 when the large plunger element 260 is in the fully closed position or the "bottom - 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 a desired disposable pipette tip by interference fit or restriction fit as described above.

[0061] Figures 6A and 6E show a rechargeable battery 280 provided within the upper housing 205. The rechargeable battery 280 within such an upper housing 205 can supply power to the piston motors 210, 225 of the pipette device 200 without the need to connect the pipette device 200 to an external outlet or other power source. The user inputs the desired dispense volume by turning / rotating the actuation element / volume control section 215 or, in some embodiments, by entering the desired volume via the interface of the LCD screen 295. In any design, feedback readings are displayed via the LCD screen 295. The volume input is sent to the device control PCB 285, which is electronically in communication with and sends signals to the motors of the device.

[0062] The pipetting device 200 during operation functions in substantially the same manner as the pipetting device 100 shown in FIGS. 1 - 5. While in the large volume range (e.g., a volume range of about 50 μL to about 1000 μL or more), the user presses the actuating element / volume control section 215. Thereby, a signal is sent to the large piston motor 210 via the device control PCB 285, and the large volume piston 230 moves upward together with the motor connection element 220, the small piston motor 225, and the large plunger element 260. Since 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 displacement of air into the fluid inlet 275, and this displacement of air draws the corresponding volume of liquid into the pipette tip. Then, when the user presses the actuating element / volume control section 215 again, the large plunger element 260 moves downward, and liquid is dispensed from the pipette tip. On the other hand, while in the small volume range (e.g., about 1 μL to about 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 actuating element / volume control section 215, a signal is sent to the small piston motor 225 via the device control PCB 285, and the small volume piston 212 and the small plunger element 270 move upward. Since the small plunger element 270 moves upward within the small vacuum chamber 265, the vacuum necessary to cause the corresponding displacement of air into the fluid inlet 275 is created, and this displacement of air draws the corresponding volume of liquid into the pipette tip. Then, when the user presses the actuating element / volume control section 215 again, the small plunger element 270 moves downward, and liquid is dispensed from the pipette tip.

[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 has been described in detail above.

[0064] Figures 7 through 8D illustrate an alternative embodiment of the pipette device 300 of the present disclosure that includes 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 is connected to the large piston motor 325's large piston 330 and small piston motor 310 such that an offset configuration is provided within the pipette housing 305 (see Figure 7). The user turns the operating element / volume control 315 as described above to enter the desired volume, and that value is displayed on the LCD screen 395. Similar to the other embodiments, the LCD screen 395 includes a user interface for selecting the desired volume. When the user enters a larger volume (e.g., a volume of about 50 μL to about 1000 μL or more), that volume input is transmitted to the device control PCB 385, which sends a signal to 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 operating element / volume control 315, the device control PCB 385 sends a signal to the large piston motor 325 to move the large 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 the 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 315 again to move the large plunger element 360 downward to the closed position, thereby discharging the liquid from the pipette tip.

[0065] When a user inputs a smaller volume (e.g., from about 1 μL to about 100 μL), the volume input is transmitted to the instrument control PCB 385, and the PCB 385 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 actuating element / volume control section 315, the instrument control PCB 385 sends a signal to the small piston motor 310, moving the small volume piston and the small plunger element 370 upward from the closed position to the open position within the small vacuum chamber 365 (see FIGS. 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 actuating element / volume control section 315 again, the small plunger element 370 moves downward to the closed position, thereby discharging the liquid from the pipette tip.

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

[0067] Reference numeral 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 actuator element) 25: Top surface (or upper surface) of the actuating element 30: Ejector element (or removal element) 35: Biasing spring (or bias spring) (large tip ejector) 40: Eject sleeve 41: Upper ejector sleeve (or upper ejector / ejection sleeve) 42: Tapered portion of the ejector sleeve 43: Intermediate ejector sleeve 44: Lower ejector sleeve (or lower ejector / 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: Biasing 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: Biasing 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 hole (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 part 220: Motor connection element 225: Large piston motor 230: Large volume piston 235: Ejector element 237: Biasing 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: Instrument control PCB 290: Bias Spring (Tip Ejector) 295: Liquid Crystal Screen (or LCD Screen) 300: Pipette 305: Pipette Housing 310: Small Piston Motor 312: Small Volume Piston 315: Actuating Element / Volume Control Section 320: Cantilever - Motor Connection Element 325: Large Piston Motor 330: Large Volume Piston 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 Charged Battery) 385: Equipment Control PCB 395: Liquid Crystal Screen (or LCD Screen)

Claims

1. A pipette comprising: a body having an open end to allow for the introduction of fluid into the body and the evacuation of fluid from the body; a fluid displacement assembly comprising a first vacuum chamber, a first plunger element, a second vacuum chamber, and a second plunger element; and An electronic drive unit for actuating the first plunger element and the second plunger element and the first vacuum chamber comprising a first bore having a first fluid inlet, a first plunger element slidably positioned within the first bore between a closed position at the first fluid inlet and an open position, the first fluid inlet being in fluid communication with the open end of the body when the first plunger element is in the open position; the second vacuum chamber comprises a second bore in the first plunger element and has a second fluid inlet, the second plunger element being slidably positioned within the second bore between a closed position at the second fluid inlet and an open position, the second fluid inlet being in fluid communication with the open end of the body when the second plunger element is in the open position; The electronic drive unit is a first motor operably connected to the first plunger element and configured to actuate the first plunger element within the first bore between a closed position and an open position; and a second motor operably connected to the second plunger element and configured to actuate the second plunger element within the second bore between the closed position and the open position; the first motor and the second motor are controlled by a control system, the control system being controlled via a user interface for operating the pipette; the second plunger element is in a closed position when the first motor causes the first plunger element to move to the open position such that a first volume of liquid aspirated by the pipette device is a distance defined by an amount substantially equal to a volume of fluid displaced by movement of the first plunger element; A pipette, wherein the first plunger element is in a closed position when the second motor causes the second plunger element to move to the open position such that a second volume of liquid aspirated by the pipette device is a distance defined by an amount approximately equal to the volume of fluid displaced by the movement of the second plunger element.

2. 2. The pipette of claim 1, wherein movement of a first plunger element from an open position to a closed position causes a first volume of liquid to be precisely dispensed from the pipette, or movement of a second plunger element from an open position to a closed position causes a second volume of liquid to be precisely dispensed from the pipette.

3. 3. A pipette according to claim 1 or 2, wherein the fluid is air.

4. A pipette according to any preceding claim, wherein the first liquid volume range has an upper limit which is greater than the upper limit of the second liquid volume range.

5. 5. The pipette of claim 4, wherein the first liquid volume range and the second liquid volume range overlap each other.

6. A pipette according to claim 4 or claim 5, wherein the first liquid volume is in the range of about 10 μL to about 1500 μL.

7. A pipette according to claim 4, claim 5 or claim 6, wherein the second liquid volume is in the range of about 0.1 μL to about 200 μL.

8. 8. A pipette according to any preceding claim, wherein the first motor is operably connected to the first plunger element by a first piston, and the second motor is operably connected to the second plunger element by a second piston.

9. 9. A pipette according to any one of claims 1 to 8, wherein the first plunger element is cylindrical and has a first cross-sectional diameter, and the second plunger element is cylindrical and has a second cross-sectional diameter, the first cross-sectional diameter being larger than the second cross-sectional diameter.

10. 10. The pipette of claim 9, wherein the first cross-sectional diameter is from about 3 mm to about 20 mm, and the second cross-sectional diameter is from about 0.5 mm to about 5 mm.

11. A pipette according to any one of claims 9 and 10, wherein the ratio of the second cross-sectional diameter to the first cross-sectional diameter is between 1:1.1 and 1:

40.

12. 12. The pipette of any one of claims 1 to 11, 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.

13. 13. The pipette of any one of claims 1 to 12, wherein the body further comprises a pipette housing and a dispenser housing, the fluid displacement assembly being at least partially disposed within the dispenser housing and the electronic drive unit being disposed within the pipette housing.

14. A pipette according to any preceding claim, wherein the dispenser housing comprises a first portion having a peripheral surface adapted to receive a pipette tip.

15. 15. The pipette of claim 14, wherein the dispenser housing further comprises a second portion having a peripheral surface configured to receive the pipette tip, the first portion having a cross-sectional diameter greater than the cross-sectional diameter of the second portion.

16. 1. A method for adjusting a volume of a pipette, comprising the steps of: (a) receiving a request volume from a user at a control module; (b) determining, at the control module, a volume range within which the received request volume falls; and (c) controlling the first motor or the second motor with a control module. Consisting of (i) the first motor moves the first plunger element from a closed position to an open position within the first vacuum chamber a distance that defines a first volume of liquid aspirated by the pipette device in an amount substantially equal to the volume of fluid displaced by the movement of the first plunger element; or (ii) a second motor moves the second plunger element from a closed position to an open position within the second vacuum chamber a distance that defines a second volume of liquid aspirated by the pipette device in an amount approximately equal to the volume of fluid displaced by the movement of the second plunger element; A second vacuum chamber is disposed within the first plunger element, and a second plunger element is slidably received in the second vacuum chamber of the first plunger element.

17. controlling the first motor or the second motor with a control module; 17. The method of claim 16, wherein a first motor moves a first plunger element from an open position to a closed position within a first vacuum chamber so that a first volume of liquid is dispensed, or a second motor moves a second plunger element from an open position to a closed position within a second vacuum chamber so that a second volume of liquid is dispensed.

18. 20. The method of claim 17, wherein the fluid displaced by movement of either the first plunger element or the second plunger element is air.

19. 19. The method of claim 17 or claim 18, wherein the first liquid volume range has an upper limit that is greater than an upper limit of the second liquid volume range.

20. The method of claim 19 , wherein the first liquid volume range and the second liquid volume range overlap each other.

21. 21. The method of claim 19 or claim 20, wherein the first liquid volume ranges from about 10 μL to about 1500 μL.

22. 22. The method of claim 19, claim 20 or claim 21, wherein the second liquid volume ranges from about 0.1 μL to about 200 μL.

23. 23. The method of any one of claims 16 to 22, wherein the first motor is operably connected to the first plunger element by a first piston, and the second motor is operably connected to the second plunger element by a second piston.

24. 24. The method of any one of claims 16 to 23, wherein the first plunger element is cylindrical and has a first cross-sectional diameter, and the second plunger element is cylindrical and has a second cross-sectional diameter, the first cross-sectional diameter being greater than the second cross-sectional diameter.

25. 25. The method of claim 24, wherein the first cross-sectional diameter is from about 3 mm to about 20 mm and the second cross-sectional diameter is from about 0.5 mm to about 5 mm.

26. 26. The method of claim 24 or claim 25, wherein the ratio of the second cross-sectional diameter to the first cross-sectional diameter is from about 1:1.1 to about 1:

40.

27. 27. The method of any one of claims 16 to 26, 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.

28. 1. A multi-volume liquid dispenser comprising: an elongated body comprising a pipette housing and a dispenser housing; a motor assembly including a first motor and a second motor disposed within the pipette housing and controlled by a control system; and the dispenser housing has an open end to allow air to be introduced into the dispenser housing and to allow air to be expelled from the dispenser housing, and the dispenser housing has a configuration to which a syringe or tip is attached; The control system is controlled via a user interface for operating the multi-volume liquid dispenser; a first motor operably connected to the large plunger for actuating the large plunger in the large cylindrical vacuum chamber between a closed position and an open position, such that movement of the large plunger to the open position causes a displacement of air into the large cylindrical vacuum chamber approximately equal to a first liquid volume aspirated by the multi-volume liquid dispenser; a second motor operably connected to the small plunger for actuating the small plunger between a closed position and an open position in a small cylindrical vacuum chamber disposed within the large plunger, wherein movement of the small plunger to the open position causes a displacement of air into the small cylindrical vacuum chamber approximately equal to a second liquid volume aspirated by the multi-volume liquid dispenser; A multi-volume liquid dispenser, wherein the large plunger is in a closed position when the small plunger is moved to an open position, and the small plunger is in a closed position when the large plunger is moved to an open position.

29. 30. The multi-volume liquid dispenser of claim 28, wherein the first motor is further configured to actuate the 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 actuate the 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.

30. 30. A multi-volume liquid dispenser according to claim 28 or claim 29, wherein the first liquid volume range and the second liquid volume range overlap each other.

31. 31. The multi-volume liquid dispenser of claim 28, claim 29 or claim 30, wherein the first liquid volume is in the range of about 10 μL to about 1500 μL and the second liquid volume is in the range of about 0.1 μL to about 200 μL.

32. A multi-volume liquid dispenser according to any one of claims 28 to 31, wherein the large plunger has a cross-sectional diameter larger than the cross-sectional diameter of the small plunger.

33. 33. The multi-volume liquid dispenser of claim 32, wherein the ratio of the cross-sectional diameter of the smaller plunger to the cross-sectional diameter of the larger plunger is from about 1:1.1 to about 1:

40.

34. 34. The multi-volume liquid dispenser of any one of claims 28 to 33, 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.

35. A multi-volume liquid dispenser according to any one of claims 28 to 34, wherein attachment of the syringe or tip to the dispenser housing is by an interference fit.

36. 36. A multi-volume liquid dispenser according to any one of claims 28 to 35, wherein the dispenser housing has at least two syringe or tip mounting surfaces, a first mounting surface having a larger peripheral surface than a peripheral surface of the second mounting surface.

37. 30. The multi-volume liquid dispenser of claim 28, further comprising a multi-stage spring-loaded ejector mechanism.

38. a multi-stage spring-loaded ejector mechanism having an upper ejection portion biased to an upper position by a first biasing element and a lower ejection portion biased to the upper position by a second biasing element, the upper ejection portion contacting the lower ejection portion to move the lower ejection portion to the first position or the second position; movement of the lower ejection portion to a first position ejects the syringe or tip from the first mounting surface when a first force is applied to the multi-stage spring-loaded ejector mechanism by a user; 38. The multi-volume liquid dispenser of claim 37, wherein movement of the lower ejection portion to the second position ejects the syringe or tip from the second mounting surface when a second force is applied to the multi-stage spring-loaded ejector mechanism by a user.

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