Multimodal strain sensor and method

Patent metadata

Field	Value
Publication number	US-11617558-B2
Application number	US-201816765081-A
Country	US
Kind code	B2
Filing date	Nov 28, 2018
Priority date	Dec 12, 2017
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

There is a viscoelastic strain sensor that includes a sensing layer including a viscoelastic material, the viscoelastic material including a viscoelastic hydrogel and a conductive nanofiller. The viscoelastic material has a fractional resistance change that increases with an increase of an applied tensile strain, and the viscoelastic material has a fractional resistance change that decreases with an applied compressional strain.

First claim

What is claimed is:

1. A viscoelastic strain sensor comprising:
a sensing layer including a viscoelastic material,
the viscoelastic material including a viscoelastic hydrogel and a conductive nanofiller,
wherein the viscoelastic material has a fractional resistance change that increases with an increase of an applied tensile strain, and
wherein the viscoelastic material has a fractional resistance change that decreases with an applied compressional strain.

2. The sensor of claim 1 , wherein the fractional resistance change under compressive strains is higher than under tensile strains.

3. The sensor of claim 1 , further comprising:
a base layer on which the sensing layer is formed; and
a protection layer that covers the sensing layer.

4. The sensor of claim 1 , wherein the conductive nanofiller includes MXene.

5. The sensor of claim 1 , wherein the conductive nanofiller includes MXene nanosheets.

6. The sensor of claim 5 , wherein the nanosheets are randomly distributed inside the viscoelastic hydrogel.

7. The sensor of claim 1 , wherein a weight by percentage of the conductive nanofiller relative to a total weight of the viscoelastic material is larger than zero and smaller than 4.

8. The sensor of claim 1 , wherein the sensing layer is malleable.

9. The sensor of claim 1 , wherein the fractional resistance change is associated with a direction of the strain applied to the sensing layer.

10. The sensor of claim 1 , wherein the fractional resistance change is associated with a speed of an object that applies the strain to the sensing layer.

11. The sensor of claim 1 , wherein the fractional resistance change is associated with a pulse applied by an object to the sensing layer.

12. A method for determining a strain with a strain sensor, the method comprising:
providing a sensing layer of the strain sensor;
applying the strain to the sensing layer;
measuring a fractional resistance change of the sensing layer due to the applied strain; and
transforming the measured fractional resistance change into a feature that characterizes the applied strain,
wherein the sensing layer includes a viscoelastic hydrogel and a conductive nanofiller,
wherein the viscoelastic material has the fractional resistance change that increases with an increase of an applied tensile strain, and
wherein the viscoelastic material has a fractional resistance change that decreases with an applied compressional strain.

13. The method of claim 12 , further comprising:
sticking the sensing layer directly on human skin.

14. The method of claim 12 , wherein the conductive nanofiller includes MXene.

15. The method of claim 12 , wherein the conductive nanofiller includes MXene nanosheets.

16. The method of claim 15 , wherein the nanosheets are randomly distributed inside the viscoelastic hydrogel.

17. The method of claim 12 , wherein a weight by percentage of the conductive nanofiller relative to a total weight of the viscoelastic material is larger than zero and smaller than 4.

18. The method of claim 12 , wherein the fractional resistance change is associated with a direction of the strain applied to the sensing layer or the fractional resistance change is associated with a speed of an object that applies the strain to the sensing layer.

19. The method of claim 12 , wherein the fractional resistance change under compressive strains is higher than under tensile strains.

20. The method of claim 12 , wherein the fractional resistance change is associated with a pulse applied by an object to the sensing layer.

21. The method of claim 12 , wherein the feature is a facial expression, a writing, or a sound.

22. A viscoelastic material comprising:
a viscoelastic hydrogel; and
a conductive nanofiller,
wherein the viscoelastic material has a fractional resistance change that increases with an increase of an applied tensile strain, and
wherein the fractional resistance change decreases with an applied compressional strain, and
wherein the fractional resistance change under compressive strains is higher than under tensile strains.

23. The viscoelastic material of claim 22 , wherein the conductive nanofiller is MXene.

24. The viscoelastic material of claim 22 , wherein a weight by percentage of the conductive nanofiller relative to a total weight is larger than zero and smaller than 4.

Assignees

• Univ King Abdullah Sci & Tech

Inventors

• Alshareef Husam Niman
• Lee Kang Hyuck
• Zhang Yizhou

Classifications

• C08K3/28

  Nitrogen-containing compounds · CPC title

• A61B2562/164

  the sensor is mounted in or on a conformable substrate or carrier · CPC title

• G01L1/2287

  constructional details of the strain gauges (adjustable resistors H01C10/00) · CPC title

• C08K7/00

  Use of ingredients characterised by shape · CPC title

• A61B5/6822

  Neck · CPC title