Composite material used as a strain gauge
In one general aspect, an apparatus comprises a material including a non-layered mixture of an polymeric foam with a plurality of voids; and a plurality of conductive fillers disposed in the polymeric foam. The apparatus may produce an electrical response to deformation and, thus, function as a strain gauge. The electrical response may be a decrease in electrical resistance. The electrical response may be an electric potential generated. The conductive fillers may include conductive nanoparticles and/or conductive stabilizers. In another general aspect, a method of measuring compression strain includes detecting, along a first axis, an electrical response generated in response to an impact to a uniform composite material that includes conductive fillers and voids disposed throughout an elastomeric polymer, and determining a deformation of the impact based on the electrical response. The impact may be along a second axis different from the first axis.
1. A porous nanoparticle-polymer composite structure comprising:
a cured polymer;
conductive nanoparticles; and
conductive fibers,
wherein the nanoparticle-polymer composite structure is cured into a shape from a mixture including a curable liquid polymer, the conductive nanoparticles, and the conductive fibers.
2. The porous nanoparticle-polymer composite structure of claim 1 , wherein the conductive fibers being up to 2.4% by weight of the porous nanoparticle-polymer composite structure.
3. The porous nanoparticle-polymer composite structure of claim 1 , wherein the conductive fibers include carbon nanotubes.
4. The porous nanoparticle-polymer composite structure of claim 1 , wherein the porous nanoparticle-polymer composite structure has a porosity with a value up to 80%.
5. The porous nanoparticle-polymer composite structure of claim 1 , wherein the porous nanoparticle-polymer composite structure has an elastic modulus with a value matching an elastic modulus of an existing foam, wherein the porous nanoparticle-polymer composite structure replaces the existing foam in an object.
6. The porous nanoparticle-polymer composite structure of claim 1 , wherein the porous nanoparticle-polymer composite structure produces an electrical response detectable along a first axis and along a second axis orthogonal to the first axis when deformed.
7. The porous nanoparticle-polymer composite structure of claim 1 , wherein the porous nanoparticle-polymer composite structure has at least one probe disposed therein, the probe being connected to a voltage detector.
8. The porous nanoparticle-polymer composite structure of claim 1 , wherein the porous nanoparticle-polymer composite structure generates a voltage in response to deformation without a current producing device.
9. A method for measuring compression strain comprising:
detecting, along a first axis, an electrical response generated in response to an impact to a porous nanoparticle-polymer composite structure comprising conductive fillers disposed throughout a cured polymer, the impact being along a second axis different from the first axis; and
determining a deformation of the impact based on the electrical response.
10. The method of claim 9 , further comprising determining a strain rate and deformation for the impact based on the electrical response.
11. The method of claim 9 , wherein the conductive fillers include conductive fibers and conductive nanoparticles.
12. The method of claim 9 , where the porous nanoparticle-polymer composite structure functions as padding in a consumer apparatus.
13. The method of claim 9 , wherein the electrical response is a voltage representing a decrease in electrical resistance or a voltage representing an electrical potential generated and the method further comprises:
transmitting data representing the voltage to an external computing device; and
determining the deformation of the impact at the external computing device based on the data.
14. The method of claim 9 , wherein the porous nanoparticle-polymer composite structure is applied to a portion of an artificial limb, and the method further comprises providing feedback to a user about the deformation of the impact.
15. The method of claim 9 , wherein the porous nanoparticle-polymer composite structure measures up to 80% strain without permanent deformation of the porous nanoparticle-polymer composite structure.
16. The method of claim 9 , wherein the conductive fillers are dispersed in the cured polymer in an even manner from outer surface to outer surface.
17. The method of claim 9 , wherein the electrical response includes a decrease in electrical resistance and an electric potential generated.
18. A porous polymer composite structure, comprising:
a uniform composite polymeric foam including conductive elements dispersed throughout the polymeric foam in an even manner from outer surface to outer surface, the conductive elements being up to 2.4% by weight of the porous polymer composite structure.
19. The porous polymer composite structure of claim 18 , wherein, the conductive elements include conductive fibers.
20. The porous polymer composite structure of claim 18 , wherein, the conductive elements are exclusively conductive fibers.
21. The porous polymer composite structure of claim 18 , the conductive elements being up to 1.5% by weight of the porous polymer composite structure.
22. The porous polymer composite structure of claim 18 , wherein the porous polymer composite structure generates, without a current producing device, electric potential in response to compression.