Liquid droplet dispenser

Patent metadata

Field	Value
Publication number	US-2016288117-A1
Application number	US-201615177512-A
Country	US
Kind code	A1
Filing date	Jun 9, 2016
Priority date	Sep 7, 2010
Publication date	Oct 6, 2016
Grant date	—

Abstract

An apparatus for dispensing droplets comprises a dispensing tip ( 2, 190, 210 ) with an orifice ( 4 ) having a cross sectional area in the range of 0.00002 mm2 to 0.03 mm2. An actuator assembly ( 13 - 15, 50, 80 ) comprising an actuator element engages with and disengage from the tip and, when engaged, couples acoustic energy to liquid in the tip to expel the liquid through the orifice as a droplet. The actuator assembly includes one or more piezo elements, which may be in the form of piezo stacks. In some embodiments, the actuator assembly comprises a plurality of jaws ( 51, 52, 61 ) adapted to move to engage with the dispensing tip for dispensing. This allows side loading of the tip ( 180 ) followed by movement of the actuator assembly ( 153 ) to engage the tip ( 180 ).

First claim

1 . A dispensing tip comprising:
a reservoir, and a fluid passage having a wall with an external surface arranged to engage an actuator assembly, and an orifice having a cross sectional area in the range of 0.00002 mm 2 to 0.03 mm 2 .

2 . The dispensing tip as claimed in claim 1 , wherein the cross-sectional area of the fluid passage is in the range of 0.01 mm 2 to 81 mm 2 .

3 . The dispensing tip as claimed in claim 1 , wherein the fluid passage wall has an angle to axial taper angle in the range of 0° to 5°.

4 . The dispensing tip as claimed in claim 1 , wherein the fluid passage wall has a funnel-shaped inner surface at the orifice, said surface extending inwardly and downwardly towards the orifice and, closer to the orifice, bending inwardly and downwardly towards the orifice at a smaller angle to axial at the orifice.

5 . The dispensing tip as claimed in claim 1 , wherein the tip is configured to be fitted to a standard pipette to allow the dispensing of drops when inserted into a suitable head assembly.

6 . The dispensing tip as claimed in claim 1 , wherein the dispensing tip further comprises a vent and a connector for connection to a pressure control system.

7 . The dispensing tip as claimed in claim 1 , wherein the dispensing tip further comprises a membrane which may be punctured for use.

8 . The dispensing tip as claimed in claim 1 , wherein the dispensing tip is of plastics material.

9 . The dispensing tip as claimed in claim 1 , wherein the dispensing tip is of polypropylene material.

10 . The dispensing tip as claimed in claim 1 , wherein the tip has a hydrophobic coating around the orifice.

11 . The dispensing tip as claimed in claim 1 , wherein the reservoir and the fluid passage have a tubular configuration terminating at the orifice.

12 . The dispensing tip as claimed in claim 1 , wherein the reservoir and the fluid passage have a funnel configuration.

13 . The dispensing tip as claimed in claim 1 , wherein there is a flow restrictor in the fluid passage.

14 . The dispensing tip as claimed in claim 1 , wherein the dispensing tip is configured for storage of liquid before dispensing.

15 . The dispensing tip as claimed in claim 1 , further comprising a removable orifice seal.

16 . A dispensing apparatus for dispensing droplets, the apparatus comprising:
a dispensing tip comprising a reservoir and a fluid passage having a wall with an external surface for engaging an actuator assembly and an orifice having a cross sectional area in the range of 0.00002 mm 2 to 0.03 mm 2 , an actuator assembly comprising an actuator element and being arranged to engage with and disengage from the tip and, when engaged, to couple acoustic energy to liquid in the fluid passage to expel said liquid through the orifice as a droplet, and a controller.

17 . The dispensing apparatus as claimed in claim 16 , wherein the actuator element is configured to engage with and disengage from the fluid passage wall external surface at a location spaced apart from the orifice.

18 . The dispensing apparatus as claimed in claim 16 , wherein the controller is configured to control the apparatus with the steps of applying:
negative liquid back pressure to prevent dripping, and acoustic energy pulses to the dispensing tip to create pressure waves for droplet dispensing.

19 . The dispensing apparatus as claimed in claim 16 , wherein the controller is configured to control the apparatus with the steps of applying:
negative liquid back pressure to prevent dripping, and positive liquid back pressure to blow out a small quantity of liquid, negative liquid back pressure, and acoustic energy pulses to the dispensing tip to create pressure waves for droplet dispensing.

20 . The dispensing apparatus as claimed in claim 16 , wherein the apparatus further comprises a sensor arranged to sense liquid dispensing from the dispensing tip, and the controller is configured to dynamically control the actuator assembly in response to said sensing of liquid dispensing.

21 . The dispensing apparatus as claimed in claim 17 , wherein the controller is configured to apply a positive back pressure to space within the tip to provide a continuous flow of liquid from the orifice, and the controller and the actuator assembly are configured to apply acoustic energy to break said stream.

22 . The dispensing apparatus as claimed in claim 16 , wherein the dispensing tip comprises a vent and the apparatus is configured for connection of the vent to a pressure control system.

23 . The dispensing apparatus as claimed in claim 16 , wherein the actuator assembly is configured to provide controlled heating in the region of the orifice only.

24 . The dispensing apparatus as claimed in claim 16 , wherein the apparatus further comprises a wiper to clean or unblock the orifice.

Assignees

• Univ Limerick

Inventors

• Leen Gabriel
• Bryce Bernard

Classifications

• B01L2300/12

  Specific details about materials · CPC title

• B01L3/0268 Primary

  using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries · CPC title

• B01L2300/0848

  Specific forms of parts of containers · CPC title

• G01N35/1009

  Characterised by arrangements for controlling the aspiration or dispense of liquids · CPC title

• B01L2300/165

  Specific details about hydrophobic, oleophobic surfaces · CPC title