Disposable cartridge for microfluidics systems

Patent metadata

Field	Value
Publication number	US-9784711-B2
Application number	US-201414402717-A
Country	US
Kind code	B2
Filing date	Jan 6, 2014
Priority date	Jan 9, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A disposable cartridge used in a digital microfluidics system has a bottom layer with first hydrophobic surface, a rigid cover plate with second hydrophobic surface, and a gap there-between. The bottom layer is a flexible film on an uppermost surface of a cartridge accommodation site of a system, attracted to and spread over the uppermost surface by an underpressure. A lower surface of the plate and the flexible bottom layer are sealed to each other. The assembled cartridge is removed from the cartridge accommodation site in one piece and potentially includes samples and processing fluids. The system has a base unit and a cartridge accommodation site with an electrode array of individual electrodes and a central control unit for controlling selection of individual electrodes and for providing these electrodes with individual voltage pulses for manipulating liquid droplets within the gap by electrowetting.

First claim

What is claimed is:

1. A digital microfluidics system ( 1 ) for manipulating samples in liquid droplets within the gap ( 6 ) between a first hydrophobic surface ( 17 ′) of a bottom layer ( 3 ) and a second hydrophobic surface ( 17 ″) of at least one disposable cartridge ( 2 ), the digital microfluidics system ( 1 ) comprising:
(a) a base unit ( 7 ) with at least one cartridge accommodation site ( 8 ) that is configured for taking up one disposable cartridge ( 2 );
(b) an electrode array ( 9 ) located at said at least one cartridge accommodation site ( 8 ) of the base unit ( 7 ), the electrode array ( 9 ) being supported by a bottom substrate ( 11 ) and substantially extending in a first plane and comprising a number of individual electrodes ( 10 ); and
(c) a central control unit ( 14 ) for controlling the selection of the individual electrodes ( 10 ) of said electrode array ( 9 ) and for providing these electrodes ( 10 ) with individual voltage pulses for manipulating liquid droplets within the gap ( 6 ) of said cartridge ( 2 ) by electrowetting,
wherein the digital microfluidics system ( 1 ) further comprises:
(d) a number of suction holes ( 35 ) that penetrate the electrode array ( 9 ) and/or the bottom substrate ( 11 ) and that are located at the cartridge accommodation site ( 8 ) of the base unit ( 7 );
(e) a vacuum source ( 33 ) for establishing an underpressure in an evacuation space ( 46 ); and
(f) a number of vacuum lines ( 34 ) that link the suction holes ( 35 ) to the vacuum source ( 33 );
wherein a gasket ( 36 ) of the digital microfluidics system ( 1 ) or of a disposable cartridge ( 2 ) is configured to seal at said cartridge accommodation site ( 8 ) the evacuation space ( 46 ), which is defined by a flexible bottom layer ( 3 ) of a disposable cartridge ( 2 ), an uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ), and the gasket ( 36 );
and wherein the underpressure in the evacuation space ( 46 ) causes the flexible bottom layer ( 3 ) that is placed at the cartridge accommodation site ( 8 ) to be attracted to and spread over the uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ), the gasket ( 36 ) defining a particular distance between said first hydrophobic surface ( 17 ′) and said second hydrophobic surface ( 17 ″).

2. The digital microfluidics system ( 1 ) of claim 1 ,
wherein the suction holes ( 35 ) are configured to mouth into suction channels ( 51 ), said suction channels ( 51 ) being arranged in the uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ).

3. The digital microfluidics system ( 1 ) of claim 1 ,
wherein the suction holes ( 35 ) are configured to mouth into a vacuum space ( 50 ), said vacuum space ( 50 ) being arranged at the cartridge accommodation site ( 8 ) and under the electrode array ( 9 ) and/or the bottom substrate ( 11 ), said vacuum space ( 50 ) being connected to the vacuum source ( 33 ) of the digital microfluidics system ( 1 ) by at least one of the vacuum lines ( 34 ).

4. The digital microfluidics system ( 1 ) of claim 1 , wherein the uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ) comprises a dielectric layer ( 24 ) that covers the electrode array ( 9 ) and the bottom substrate ( 11 ), the dielectric layer ( 24 ) having holes at the sites of the of suction holes ( 35 ) of the base unit ( 7 ).

5. The digital microfluidics system ( 1 ) of claim 4 ,
wherein the gasket ( 36 ) is fixed to the dielectric layer ( 24 ) that permanently covers the electrode array ( 9 ) and the bottom substrate ( 11 ) of a cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ).

6. The digital microfluidics system ( 1 ) of claim 4 ,
wherein the gasket ( 36 ) is permanently fixed to the bottom substrate ( 11 ) that supports the electrode array ( 9 ); the dielectric layer ( 24 ) permanently covering the bottom substrate ( 11 ), the electrode array ( 9 ), and the gasket ( 36 ).

7. The digital microfluidics system ( 1 ) of claim 1 ,
wherein the base unit ( 7 ) comprises an insertion guide ( 25 ) that is configured as a frame, which is sized to accommodate a disposable cartridge ( 2 ) therein.

8. The digital microfluidics system ( 1 ) of claim 1 , wherein the uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ) is defined by the bottom substrate ( 11 ) and bare metal surfaces of the individual electrodes ( 10 ).

9. The digital microfluidics system ( 1 ) of claim 1 ,
wherein the base unit ( 7 ) comprises a clamp ( 37 ) that is configured to fix a disposable cartridge ( 2 ) at a desired position of a cartridge accommodation site ( 8 ) of the base unit ( 7 ).

10. A disposable cartridge ( 2 ) for use in a digital microfluidics system ( 1 ) according to claim 1 , the disposable cartridge ( 2 ) comprising:
(a) a bottom layer ( 3 ) with a first hydrophobic surface ( 17 ′) that is impermeable to liquids and that is configured as a working film for manipulating samples in liquid droplets ( 23 ) thereon utilizing an electrode array ( 9 ) of the digital microfluidics system ( 1 ) when the bottom layer ( 3 ) of the disposable cartridge ( 2 ) is placed over said electrode array ( 9 );
(b) a plane rigid cover plate ( 12 ) comprising a lower surface ( 48 ′), at least one through hole ( 19 ) located at a loading site ( 41 ), and a second hydrophobic surface ( 17 ″) that is at least permeable to ions; and
(c) a gap ( 6 ) that is located between the first hydrophobic surface ( 17 ′) of the bottom layer ( 3 ) and the second hydrophobic surface ( 17 ″) of the rigid cover plate ( 12 ),
wherein the bottom layer ( 3 ) is configured as a flexible film that is configured to be laid on an uppermost surface ( 52 ) of a cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ) and to be attracted to and spread over said uppermost surface ( 52 ) by the underpressure in the evacuation space ( 46 ), wherein the disposable cartridge ( 2 ) is configured to be assembled at the cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ), the lower surface ( 48 ′) of the rigid cover plate ( 12 ) and the flexible bottom layer ( 3 ) being configured as sealingly attachable to each other along a circumference ( 40 ) of the flexible bottom layer ( 3 ) by mutual contacting the lower surface ( 48 ′) of the rigid cover plate ( 12 ) and the circumference ( 40 ) of the flexible bottom layer ( 3 ) that is spread over the uppermost surface ( 52 ) of the cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 );
and wherein the assembled disposable cartridge ( 2 ) is configured to be removed from the cartridge accommodation site ( 8 ) in one piece that comprises the bottom layer ( 3 ), the plane rigid cover plate ( 12 ), and the gap ( 6 ) that potentially comprises samples and processing fluids.

11. The disposable cartridge ( 2 ) of claim 10 ,
wherein the flexible bottom layer ( 3 ) is configured to be sealingly attached at the cartridge accommodation site ( 8 ) of the digital microfluidics system ( 1 ) to the rigid cover plate ( 12 ) along the circumference ( 40 ) of the flexible bottom layer ( 3 ):
(i) by at least one adhesive tape or glue strip, or
(ii) by welding.

12. The disposable cartridge ( 2 ) of claim 10 ,
wherein the loading sites ( 41 ) are selected from a group comprising piercing sites ( 41 ′) and pipetting orifices ( 41 ′″).

13. The disposable cartridge ( 2 ) of claim 10 ,
wherein to an upper surface ( 49 ′) of the rigid cover plate ( 12 ) is sealingly applied a pierceable membrane ( 31 ) that is configured to seal

Assignees

• Tecan Trading Ag

Inventors

• Hoffmeyer Daniel
• Lay Tiffany
• Lee Travis
• Feiglin Marc N
• Halg Werner
• Kopf-Sill Anne R

Classifications

• B01L3/502715 Primary

  characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces · CPC title

• G01N27/44791 Primary

  Microapparatus (sample containers with integrated microfluidic structures B01L3/5027) · CPC title

• G01N27/44756

  Apparatus specially adapted therefor · CPC title

• B81B1/00

  Devices without movable or flexible elements, e.g. microcapillary devices · CPC title

• B01L3/505

  Flexible containers without fluid transport within · CPC title