Liquid column-based capacitive sensors

Patent metadata

Field	Value
Publication number	US-2016365198-A1
Application number	US-201615178092-A
Country	US
Kind code	A1
Filing date	Jun 9, 2016
Priority date	Dec 14, 2013
Publication date	Dec 15, 2016
Grant date	—

Abstract

A liquid column-based normal/shear pressure/force sensing device having an elastic electrolyte-electrode contact with large interfacial capacitance to achieve high sensitivity and resolution with flexible and transparent constructs.

First claim

What is claimed is:

1 . An array of droplet-based sensors, comprising:
a plurality of sensing chambers each having interior volumes housed by a first substrate and a second substrate; wherein each of the plurality of sensing chambers comprise a substrate separation structure maintaining a periphery of said first and second substrates at a fixed separation distance to form each of said plurality of sensing chambers; at least a first electrode and second electrode coupled to the interior volume of each of the plurality of sensing chambers; and an electrolytic liquid retained in each of the plurality of sensing chambers; said electrolytic liquid disposed in the sensing chamber to form a contact with said first and second electrodes; wherein in response to an applied force, at least one of said substrates deforms, thereby changing the contact between the electrolytic liquid and the first and second electrodes and thus the electrical properties between said first and second electrodes.

2 . The array of claim 1 , wherein said properties are selected from the group of electrical properties consisting of interfacial electric double layers (EDL) capacitance, resistance, impedance including both resistance and capacitance, and inductance which are sensed as a measure of pressure/force applied to each of said droplet-based pressure/force sensors.

3 . The array of claim 1 , wherein the electrolytic liquid comprises an electrolyte droplet.

4 . The array of claim 1 , wherein the electrolytic liquid comprises a column of electrolyte.

5 . The array of claim 1 , wherein the electrolytic liquid fills the sensing chamber.

6 . The array of claim 1 , wherein the electrolytic liquid is centrally aligned in the sensing chamber.

7 . The array of claim 1 , wherein the electrolytic liquid is aligned to one side of the sensing chamber.

8 . The array of claim 1 , wherein one or more surfaces of the chamber comprise a hydrophobic region to retain the electrolytic liquid at a specified location within the chamber.

9 . The array of claim 1 , wherein one or more surfaces of the chamber comprise a micropillar structure to retain the electrolytic liquid at a specified location within the chamber.

10 . The array of claim 1 , further comprising:
a channel in fluid communication with the chamber; said first electrode and second electrode coupled to one or more surfaces of the channel; wherein the electrolytic liquid is forced into the channel in response to the applied force to the sensor.

11 . The array of claim 10 , further comprising:
a second channel in fluid communication with the chamber; said first electrode and second electrode coupled to one or more surfaces of the second channel; wherein the electrolytic liquid is forced into the second channel in response to the applied force to the sensor.

12 . The array of claim 1 , wherein the force comprises a normal, shear or pressure force applied to the sensor.

13 . The array of claim 1 , wherein at least one of said first electrode and said second electrode is connected in common within each of said array of sensors.

14 . The array of claim 1 , wherein both said first electrode and said second electrode are connected in common within each of said array of droplet-based pressure/force sensors.

15 . The array of claim 1 , wherein said first electrode and said second electrode are disposed on opposing sides of the sensor chamber.

16 . The array of claim 1 , wherein said first electrode and said second electrode are disposed in a coplanar orientation on one side of the sensor chamber.

17 . The array of claim 1 , wherein one or more of the first and second substrates comprises a cavity to form said separation structure.

18 . The array of claim 1 , wherein at least one of said first or second substrates is flexible.

19 . A liquid-based sensing apparatus, comprising:
at least one sensing chamber comprising an interior volume housed by a first substrate and a second substrate; wherein the sensing chamber comprises a substrate separation structure maintaining a periphery of said first and second substrates at a fixed separation distance to form the sensing chamber; at least a first electrode and second electrode coupled to the interior volume of the sensing chamber; and an electrolytic liquid retained in the sensing chamber; said electrolytic liquid disposed in the sensing chamber to form a contact with said first and second electrodes; wherein in response to an applied force, at least one of said substrates deforms, thereby changing the contact between the electrolytic liquid and the first and second electrodes and thus the electrical properties between said first and second electrodes.

20 . The apparatus of claim 19 , wherein said properties are selected from the group of electrical properties consisting of interfacial electric double layers (EDL) capacitance, resistance, impedance including both resistance and capacitance, and inductance which are sensed as a measure of pressure/force applied to each of said droplet-based pressure/force sensors.

21 . The apparatus of claim 19 , wherein the electrolytic liquid comprises an electrolyte droplet.

22 . The apparatus of claim 19 , wherein the electrolytic liquid comprises a column of electrolyte.

23 . The apparatus of claim 19 , wherein the electrolytic liquid fills the sensing chamber.

24 . The apparatus of claim 19 , wherein the electrolytic liquid is centrally aligned in the sensing chamber.

25 . The apparatus of claim 19 , wherein the electrolytic liquid is aligned to one side of the sensing chamber.

26 . The apparatus of claim 19 , wherein one or more surfaces of the chamber comprise a hydrophobic region to retain the electrolytic liquid at a specified location within the chamber.

27 . The apparatus of claim 19 , wherein one or more surfaces of the chamber comprise a micropillar structure to retain the electrolytic liquid at a specified location within the chamber.

28 . The apparatus of claim 19 , further comprising:
a channel in fluid communication with the chamber; said first electrode and second electrode coupled to one or more surfaces of the channel; wherein the electrolytic liquid is forced into the channel in response to the applied force to the sensor.

29 . The apparatus of claim 28 , further comprising:
a second channel in fluid communication with the chamber; a third electrode and fourth electrode coupled to one or more surfaces of the second channel; wherein the electrolytic liquid is forced into the second channel in response to the applied force to the sensor; and wherein the first electrode, second electrode, third electrode and fourth electrode are capable of individually detecting the electrical properties of the first channel and the second channel.

30 . The apparatus of claim 19 , wherein the force comprises a normal, shear or pressure force applied to the sensor.

31 . The apparatus of claim 19 , wherein said first electrode and said second electrode are disposed on opposing sides of the sensor chamber.

32 . The apparatus of claim 19 , wherein said first electrode and said second electrode are disposed in a coplanar orientation on one side of the sensor chamber.

33 . The apparatus

Assignees

• Univ California

Inventors

• Pan Tingrui
• Nie Baoqing
• Li Ruya
• Brandt James D

Classifications

• G01L1/142

  using capacitors · CPC title

• A61B5/021 Primary

  Measuring pressure in heart or blood vessels · CPC title

• A61B2562/0247

  Pressure sensors · CPC title

• H01G11/08 Primary

  Structural combinations, e.g. assembly or connection, of hybrid or EDL capacitors with other electric components, at least one hybrid or EDL capacitor being the main component · CPC title

• H01G5/0132

  Liquid dielectrics · CPC title