Resistive microfluidic pressure sensor

Patent metadata

Field	Value
Publication number	US-10488276-B2
Application number	US-201615559617-A
Country	US
Kind code	B2
Filing date	Mar 23, 2016
Priority date	Mar 24, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A resistive microfluidic pressure sensor is provided which comprises a first layer comprising a microfluidic channel with a carbon-based conductive liquid and a second layer comprising at least two electrodes, the at least two electrodes being adapted to measure resistance of the carbon-based conductive liquid upon deformation of the microfluidic channel as a result of a change in force applied on a surface of the sensor.

First claim

The invention claimed is:

1. A resistive microfluidic pressure sensor comprising:
a first layer comprising a microfluidic channel, the microfluidic channel comprising a conductive liquid; and
a second layer comprising at least two electrodes, the at least two electrodes being adapted to measure resistance of the conductive liquid upon deformation of the microfluidic channel as a result of a change in force applied on a surface of the sensor;
wherein the first layer and the second layer are arranged to seal the conductive liquid within the microfluidic channel, the conductive liquid being interposed between the first layer and the second layer.

2. The sensor according to claim 1 , wherein the sensor is flexible.

3. The sensor according to claim 1 , wherein the first layer and the second layer are of the same or different material, and are formed from an elastomeric material.

4. The sensor according to claim 1 , wherein the first layer and the second layer are of the same or different material, wherein the material comprises silicone rubber, latex rubber, nitrile rubber, polyurethane (PU), polyvinylidene fluoride (PVDF), ethylene vinyl acetate (EVA), polyvinyl alcohol (PVA), polyethylene (PE), polypropylene (PP), polystyrene (PS), polydimethylsiloxane (PDMS), polybutyrate, polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI), or a combination thereof.

5. The sensor according to claim 4 , wherein the first layer comprises silicone rubber and the second layer comprises PDMS.

6. The sensor according to claim 1 , wherein the change in force is from a change in pressing force, bending force, shearing force or stretching force.

7. The sensor according to claim 1 , wherein application of a force on the surface of the sensor causes deformation of the microfluidic channel thereby decreasing the cross-sectional area of the microfluidic channel and increasing the resistance of the conductive liquid.

8. The sensor according to claim 1 , wherein the conductive liquid comprises nanoparticles.

9. The sensor according to claim 8 , wherein the nanoparticles are metallic nanoparticles, carbon-based nanoparticles, or a combination thereof.

10. The sensor according to claim 1 , wherein the conductive liquid is a carbon-based conductive liquid.

11. The sensor according to claim 10 , wherein the carbon-based conductive liquid comprises: graphene, graphene oxide, reduced graphene oxide, graphite, fullerene, carbon nanotubes, carbon black, functionalized carbon-based nanomaterials, or a combination thereof.

12. The sensor according to claim 10 , wherein the carbon-based conductive liquid is a graphene oxide having a concentration greater or equal to 3.0 mg/mL.

13. The sensor according to claim 1 , wherein the second layer is formed of multiple layers.

14. The sensor according to claim 1 , wherein the microfluidic channel comprises a protrusion, the protrusion being configured to detect changes in surface texture.

15. The sensor according to claim 14 , such that application of a shear force on the protrusion leads to deformation of the microfluidic channel, thereby decreasing the cross-sectional area of the microfluidic channel and increasing the resistance of the conductive liquid.

Assignees

• Nat Univ Singapore

Inventors

• Kenry
• Yeo Joo Chuan
• Lim Chwee Teck

Classifications

• G01L1/02 Primary

  by hydraulic or pneumatic means · CPC title

• G01L1/22

  using resistance strain gauges · CPC title

• G01L5/226

  to manipulators, e.g. the force due to gripping · CPC title

• A61B5/225

  of the fingers, e.g. by monitoring hand-grip force · CPC title

• G01L1/20

  by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids (of piezo-resistive materials G01L1/18); by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress · CPC title