# US 9,752,861 B2 · Flexible strain sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,861 B2 - Document ID: US9752861B2 - Status: Granted - Kind: B2 - Application number: 14/438,397 - Filed: 2013-10-25 - Published: 2015-10-01 - Granted: 2017-09-05 - Earliest claimed: 2012-10-26 - Assignees: Board of Regents, The University of Texas System - Applicants: Board of Regents, The University of Texas System - Inventors: Uday Tata; Smitha Rao; Jung-Chih Chiao - Web page: https://patentgrep.com/patent/US9752861B2 ## CPC - G01B 7/16: for measuring the deformation in a solid, e.g. by resistance strain gauge - A61F 2/1613: {having special lens configurations, e.g. multipart lenses; having particular optical properties, e.g. pseudo-accommodative lenses, lenses having aberration corrections, diffractive lenses, lenses for variably absorbing electromagnetic radiation, lenses having variable focus} - C23C 14/0605: {Carbon} - C23C 14/35: by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} - C23C 14/5813: {using lasers} - G02C 11/10: {Electronic devices other than hearing aids} - A61F 2/16: Intraocular lenses - G02C 7/04: Contact lenses for the eyes (disinfection or sterilisation of contact lenses A61L12/00) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00) ## Abstract In one embodiment, a flexible strain sensor includes a flexible substrate having a top surface and a layer of piezoresistive amorphous carbon formed on the top surface of the substrate. ## Claims ### Claim 1 A flexible strain sensor comprising: a flexible polymeric substrate having a top surface; and a layer of amorphous carbon formed on the top surface of the substrate; wherein the sensor comprises a meandered active region formed by the substrate and the layer of amorphous carbon, the substrate and the layer of amorphous carbon both tracing a meandered line within the active region. ### Claim 2 (depends on 1) The sensor of claim 1, wherein the substrate is biocompatible. ### Claim 3 (depends on 1) The sensor of claim 1, wherein the substrate is a polyimide substrate. ### Claim 4 (depends on 1) The sensor of claim 1, where in the substrate is approximately 1 μm to 500 μm thick. ### Claim 5 (depends on 1) The sensor of claim 1, wherein the amorphous carbon layer is approximately 0.01 μm to 100 μm thick. ### Claim 6 (depends on 1) The sensor of claim 1, wherein the sensor further comprises end members provided at ends of the active region. ### Claim 7 (depends on 6) The sensor of claim 6, wherein the active region comprises multiple parallel meandered lines. ### Claim 8 (depends on 7) The sensor of claim 7, wherein the active region further comprises lateral segments that join the meandered lines. ### Claim 9 An optical device comprising: a lens body; and a flexible strain sensor provided on the lens body, the sensor including a flexible polymeric substrate having a top surface and a layer of amorphous carbon formed on the top surface of the substrate, wherein the sensor comprises a meandered active region formed by the substrate and the layer of amorphous carbon, the substrate and the layer of amorphous carbon both tracing a meandered line within the active region. ### Claim 10 (depends on 9) The device of claim 9, wherein the device is an implantable intraocular lens. ### Claim 11 (depends on 10) The device of claim 10, wherein the implantable intraocular lens further comprises arms that extend from the body and wherein a strain sensor is provided on each arm. ### Claim 12 (depends on 10) The device of claim 10, wherein the implantable intraocular lens comprises a body and wherein a strain sensor is provided at each of multiple positions around the periphery of the body. ### Claim 13 (depends on 9) The device of claim 9, wherein the device is a contact lens. ### Claim 14 (depends on 13) The device of claim 13, wherein contact lens comprises a body and wherein a strain sensor is provided at each of multiple positions around the periphery of the body. ### Claim 15 (depends on 1) The sensor of claim 1, wherein the meandered line comprises multiple parallel lateral segments and multiple parallel linear segments. ### Claim 16 (depends on 1) The sensor of claim 1, wherein sensor is embedded in an elastic material. ### Claim 17 (depends on 9) The device of claim 9, wherein the meandered line comprises multiple parallel lateral segments and multiple parallel linear segments. ### Claim 18 (depends on 9) The device of claim 9, wherein sensor is embedded in an elastic material.