# US 11,304,476 B2 · Variable stiffness apparatuses using an interconnected dual layer fluid-filled cell array > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,304,476 B2 - Document ID: US11304476B2 - Status: Granted - Kind: B2 - Application number: 16/465,928 - Filed: 2017-12-01 - Published: 2020-07-16 - Granted: 2022-04-19 - Earliest claimed: 2016-12-01 - Assignees: Board of Regents, The University of Texas System - Applicants: The Board of Regents of the University of Texas System - Inventors: Muthu B. J. Wijesundara; Wei Carrigan; Mahdi Haghshenas-Jaryani - Web page: https://patentgrep.com/patent/US11304476B2 ## CPC - A43B 13/189: {filled with a non-compressible fluid, e.g. gel, water} - A47C 7/144: {with array of movable supports} - A43B 13/182: {Helicoidal springs} - A43B 17/02: wedge-like or resilient - A43B 17/03: filled with a gas, e.g. air - A47C 23/002: {with separate resilient support elements, e.g. elastomeric springs arranged in a two-dimensional matrix pattern} - A47C 27/08: Fluid mattresses - A47C 27/081: {of pneumatic type} - A61G 5/1043: {Cushions specially adapted for wheelchairs} - B32B 3/085: {spaced apart pieces on the surface of a layer} - B60N 2/643: {shape of the back-rests (B60N2/66 takes precedence)} - B60N 2/646: {shape of the cushion} - A43B 13/20: Pneumatic soles {filled with a compressible fluid, e.g. air, gas (inflatable linings for skiboots A43B5/0407)} - A47C 27/085: {of liquid type, e.g. filled with water or gel} - Y10T 428/24331: including nonapertured component - A43B: CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR - A47C: CHAIRS; SOFAS; BEDS - A61G: TRANSPORT, PERSONAL CONVEYANCES OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS (appliances for aiding patients or disabled persons to walk A61H3/00); OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES (embalming corpses A01N1/00) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B60N: SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Variable stiffness apparatuses using an interconnected dual layer fluid-filled cell array. One example of the present apparatuses comprises: a substrate having a first side and a second side; and a plurality of structures coupled to the substrate, where each structure comprises: a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end, the first portion defining a first chamber; and a second portion having a first end, a second end, and a sidewall extending between the first end and the second end, the second portion defining a second chamber in fluid communication with the first chamber; where each of the plurality of structures is coupled to the substrate such that the first portion is disposed on the first side of the substrate, and the second chamber is disposed on the first side or the second side of the substrate. ## Claims ### Claim 1 An apparatus comprising: a substrate having a first side and a second side; and a plurality of structures coupled to the substrate, where each structure comprises: a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end, the first portion defining a single first chamber; and a second portion having a first end, a second end, and a sidewall extending between the first end and the second end, the second portion defining a single second chamber in fluid communication with the first chamber, where each of the plurality of structures is coupled to the substrate such that the first portion is disposed on the first side of the substrate, and the second chamber is disposed on the second side of the substrate, and where for each structure the first portion of the structure and the second portion of the structure are not in fluid communication with any other structures of the plurality of structures. ### Claim 2 (depends on 1) The apparatus of claim 1, where the substrate comprises a plurality of apertures and each of the plurality of structures are disposed through a respective one of the plurality of apertures. ### Claim 3 (depends on 1) The apparatus of claim 1, where the plurality of structures are each configured to be coupled to a fluid source such that the fluid source can deliver fluid to the first chamber and/or the second chamber to vary internal pressures of the plurality of structures. ### Claim 4 (depends on 1) The apparatus of claim 1, where pressure in the first chamber is equal to pressure in the second chamber. ### Claim 5 (depends on 1) The apparatus of claim 1, where the first chamber and the second chamber include a liquid. ### Claim 6 (depends on 5) The apparatus of claim 5, where the liquid comprises a gel. ### Claim 7 (depends on 1) The apparatus of claim 1, where the sidewall of the first portion includes a planar surface and/or a corrugated surface. ### Claim 8 (depends on 1) The apparatus of claim 1, where the first portion forms a bellows. ### Claim 9 (depends on 1) The apparatus of claim 1, where the first end of the first portion and/or the first end of the second portion includes a planar and/or rounded surface. ### Claim 10 (depends on 1) The apparatus of claim 1, where the second portion is flexible such that compression of the first portion causes the second portion to expand. ### Claim 11 (depends on 10) The apparatus of claim 10, where the sidewall of the second portion has a thickness ranging from 0.05-30 mm. ### Claim 12 (depends on 1) The apparatus of claim 1, where the second portion is rigid and includes a piston and a biasing member disposed in the second chamber, the piston being movable relative to the second portion to a first position in response to a fluid force of a fluid within the first chamber acting on the piston being greater than a biasing force of the biasing member acting on the piston and to a second position in response to the biasing force being greater than the fluid force. ### Claim 13 (depends on 1) The apparatus of claim 1, where the first portion and/or the second portion includes a polymer. ### Claim 14 (depends on 13) The apparatus of claim 13, where the polymer comprises at least one material selected from the group consisting of: urethane, silicone, latex, neoprene, isoprene, and nylon. ### Claim 15 An apparatus comprising: a substrate having a first side and an opposing second side; and a plurality of structures coupled to the substrate, where each structure comprises: a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end, the first portion defining a single first chamber; and a second portion having a first end, a second end, and a sidewall extending between the first end and the second end, the second portion defining a single second chamber; a medial portion extending between the first and second portions, the medial portion defining a single channel in fluid communication with the first chamber and the second chamber; where each of the plurality of structures is coupled to the substrate such that each of the first and second portions is disposed on the first side of the substrate, and where for each structure the first portion of the structure and the second portion of the structure are not in fluid communication with any other structures of the plurality of structures. ### Claim 16 An apparatus comprising: a substrate having a first side, a second side, and an aperture extending between the first side and the second side; and a structure extending through the aperture of the substrate, the structure comprising: a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end, the first portion defining a single first chamber; and a second portion having a first end, a second end, and a sidewall extending between the first end and the second end, the second portion defining a single second chamber in fluid communication with the first chamber; a medial portion extending between the first and second portions, the medial portion defining a single channel in fluid communication with the first chamber and the second chamber; where the medial portion is disposed in the aperture such that the first portion is disposed on the first side of the substrate, and the second portion is disposed on the second side of the substrate, where the first chamber and the second chamber include a liquid.