# US 11,027,423 B2 · Soft robotic actuators utilizing asymmetric surfaces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,423 B2 - Document ID: US11027423B2 - Status: Granted - Kind: B2 - Application number: 16/042,459 - Filed: 2018-07-23 - Published: 2018-11-15 - Granted: 2021-06-08 - Earliest claimed: 2014-06-09 - Assignees: Soft Robotics, Inc. - Applicants: Soft Robotics, Inc. - Inventors: Joshua Aaron Lessing; Ryan Richard Knopf; Noel McLellan - Web page: https://patentgrep.com/patent/US11027423B2 ## CPC - B25J 9/142: {comprising inflatable bodies} - B25J 15/0023: {Gripper surfaces directly activated by a fluid (flexible fingers B25J15/12)} - B25J 15/0616: {with vacuum} - B25J 15/083: {with means for locking the fingers in an open or closed position} - B25J 15/10: with three or more finger members {(B25J15/0009 takes precedence)} - B25J 15/12: with flexible finger members - F15B 15/103: {using inflatable bodies that contract when fluid pressure is applied, e.g. pneumatic artificial muscles or McKibben-type actuators} - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR ## Abstract A soft robotic actuator is disclosed. The actuator includes a first portion with a substantially constant profile and a second portion with a regularly varying profile, and bends in a pressure-dependent fashion as the internal pressure within the actuator is increased or decreased. ## Claims ### Claim 1 A soft robotic actuator, comprising: an elongate body having a first wall portion having a first profile and a second wall portion disposed opposite the first wall portion, the second wall portion having a repeating variable profile such that a height of the elongate body varies over its length, wherein (a) the elongate body defines a sealed void which is capable of being pressurized relative to the environment around the actuator, and (b) a distal end-of the elongate body is configured to exhibit angular displacement under pressurization, due at least in part to the repeating variable profile of the second wall portion, wherein the angular displacement increases in direct proportion to the pressure applied from an ambient pressure to a pressure according to a final curve profile. ### Claim 2 (depends on 1) The soft robotic actuator of claim 1, wherein a length of the second wall portion increases relative to a length of the first wall portion when the portion of the elongate body is bent, wherein the portion of the elongate body is bent when the pressurizing causes a corresponding part of the second wall of the elongate body to unfold. ### Claim 3 (depends on 1) The soft robotic actuator of claim 1, wherein the second wall portion comprises a plurality of unit cells, wherein each unit cell comprises a respective maximal wall height and a respective minimal wall height, wherein the maximal and minimal wall heights are relative to the first wall portion of the corresponding unit cell. ### Claim 4 (depends on 3) The soft robotic actuator of claim 3, wherein the soft robotic actuator has a constant radius of curvature when: (i) the maximal wall heights of each unit cell are substantially equal, and (ii) the minimal wall heights of each unit cell are substantially equal. ### Claim 5 (depends on 3) The soft robotic actuator of claim 3, wherein the soft robotic actuator has a variable radius of curvature when at least one of: (i) the respective maximal wall heights of a first unit cell and a second unit cell, of the plurality of unit cells, are different, (ii) a wall thickness of the first unit cell is different than a wall thickness of the second unit cell, and (iii) a pitch distance between a first two adjacent unit cells of the plurality of unit cells is different than a pitch distance between a second two adjacent unit cells of the plurality of unit cells. ### Claim 6 (depends on 1) The soft robotic actuator of claim 1, wherein the bend comprises one or more of: (i) multi-directional bending of the elongate body, and (ii) twisting of the elongate body, responsive to the pressurizing. ### Claim 7 (depends on 1) The soft robotic actuator of claim 1, wherein a degree of actuation of the soft robotic actuator is based on an amount of pressure in the pressurized sealed void. ### Claim 8 (depends on 7) The soft robotic actuator of claim 7, wherein the degree of actuation is further based on one or more of: (i) the height of the elongate body, (ii) a respective pitch difference between two adjacent unit cells, of a plurality of unit cells of the second wall portion, and (iii) a respective wall thickness of each unit cell. ### Claim 9 (depends on 1) The soft robotic actuator of claim 1, wherein the elongate body curves around the first wall portion when bent. ### Claim 10 (depends on 1) The soft robotic actuator of claim 1, wherein the elongate body comprises an elastic elongate body that returns to an original shape in the absence of pressurization in the sealed void. ### Claim 11 (depends on 1) The soft robotic actuator of claim 1, further comprising a tapered distal end. ### Claim 12 A device, comprising: a plurality of soft robotic actuators arranged to define a grasping member, each soft robotic actuator including a flexible elongate body, each elongate body comprising a first wall portion having a substantially constant profile and a second wall portion disposed opposite the first wall portion, the second wall portion having a repeating variable profile such that a height of the elongate body varies over its length, wherein (a) each elongate body defines a sealed void which is capable of being pressurized relative to the environment around the corresponding actuator, and (b) each elongate body is configured to exhibit angular displacement of its distal end under pressurization, due at least in part to the repeating variable profile of the second wall portion, wherein the angular displacement increases in direct proportion to the pressure applied from an ambient pressure to a pressure according to a final curve profile. ### Claim 13 (depends on 12) The device of claim 12, wherein the plurality of actuators are arranged about a single longitudinal axis. ### Claim 14 (depends on 12) The device of claim 12, wherein a distal end of each actuator defines a grasping area which increases or decreases based on an amount of pressure in the sealed void of each elongate body. ### Claim 15 (depends on 12) The device of claim 12, wherein a length of the second wall portion of each actuator increases relative to a length of the first wall portion when the respective portion of the respective elongate body is bent, wherein a respective portion of the respective elongate body is bent when the pressurizing causes a corresponding part of the second wall of the elongate body to unfold. ### Claim 16 (depends on 12) The device of claim 12, wherein the second wall portion of each actuator comprises a plurality of unit cells, wherein each unit cell comprises a respective maximal wall height and a respective minimal wall height, wherein the maximal and minimal wall heights are relative to the first wall portion of the corresponding unit cell. ### Claim 17 (depends on 1) A method of actuating a soft robotic actuator, the method comprising: providing a soft robotic actuator of claim 1; and pressurizing the soft robotic actuator to cause the second wall to expand preferentially, thereby causing the soft robotic actuator to bend around the first wall of the soft robotic actuator. ### Claim 18 (depends on 1) The soft robotic actuator of claim 1, wherein the predetermined range of pressures at least includes 1-5 PSI. ### Claim 19 (depends on 1) The soft robotic actuator of claim 1, wherein the predetermined range of pressures is 0-15 PSI.