Soft robotic actuators

• US 9,464,642 B2
• Filed: 11/21/2011
• Issued: 10/11/2016
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: Morin, Stephen, Ilievski, Filip, Chen, Xin, Mazzeo, Aaron D., Whitesides, George M., Shepherd, Robert F., Martinez, Ramses V., Choi, Won Jae, Kwok, Sen W., Stokes, Adam, Nie, Zhihong
• Primary Examiner(s): Lazo, Thomas E
• Application Number:
  US13/885,967
• Publication Number:
  US 20140109560A1
• Time in Patent Office: 1,786 Days
• Field of Search: 92/92
• US Class Current: 1/1
• CPC Class Codes: B25J 11/00 Manipulators not otherwise provided for
• CPC Class Codes: B25J 9/1075 with muscles or tendons
• CPC Class Codes: B25J 9/142 comprising inflatable bodies
• CPC Class Codes: F15B 15/10 the motor being of diaphragm type
• CPC Class Codes: F15B 7/06 Details F15B15/00 takes precedence

Abstract

A soft robotic device includes a flexible body having a width, a length and a thickness, wherein the thickness is at least 1 mm, the flexible body having at least one channel disposed within the flexible body, the channel defined by upper, lower and side walls, wherein at least one wall is strain limiting; and a pressurizing inlet in fluid communication with the at least one channel, the at least one channel positioned and arranged such that the wall opposite the strain limiting wall preferentially expands when the soft robotic device is pressurized through the inlet.

Claims

1. A soft body robotic device, comprising:

a flexible molded body having a plurality of interconnected chambers disposed within the molded body, wherein a portion of the molded body is comprised of an elastically extensible material and a portion of the molded body is strain limiting relative to the elastically extensible material, and wherein the thickness of the molded body is at least 1 mm; and

a pressurizing inlet that is configured to receive fluid for the plurality of interconnected chambers,

wherein the molded body is configured to preferentially expand when the plurality of interconnected chambers are pressurized by the fluid, causing a bending motion around the strain limiting portion of the molded body; and

wherein the strain limiting portion has a wall thickness greater than other portions of the flexible molded body.

2. The soft robotic device of claim 1, wherein the device is free of a rigid weight-bearing skeleton.

3. The soft robotic device of claim 1, wherein the strain limiting portion or member is formed using a material with higher elastic modulus compared to that of a material forming other portions of the flexible molded body.

4. The soft robotic device of claim 1, wherein the molded body comprises a reinforcing material to increase toughness and resistance to damage.

5. The soft robotic device of claim 1, wherein the flexible molded body and the plurality of interconnected chambers each have a longitudinal axis, and wherein the longitudinal axes of the plurality of interconnected chambers are positioned and arranged at an angle with respect to the longitudinal axis of the flexible molded body, wherein the angle is between zero and 90 degrees.

6. The soft robotic device of claim 1, wherein a thickness of the flexible molded body is in the range of about 5 mm and 5 cm.

7. The soft robotic device of claim 1, wherein the flexible molded body further includes a functional feature disposed on a surface of the flexible molded body.

8. The soft robotic device of claim 7, wherein the functional feature is one or more features selected from the group consisting of a traction layer, a bidirectional fabric layer, a camouflage layer, a self-healing layer, suction cups and magnets.

9. The soft robotic device of claim 8, wherein the self-healing layer comprises a self-sealing layer disposed on a portion of the flexible molded body, wherein the self-sealing layer includes a material of lower elastic modulus compared to that of a material forming the flexible molded body.

10. The soft robotic device of claim 8, wherein the camouflaging layer includes a plurality of fluid chambers and a plurality of fluid inlets, wherein each of the plurality of fluid chambers is in fluid communication with one of the plurality of fluid inlets.

11. A method of camouflaging a soft robotic device, the method comprising:

providing a soft robot according to claim 10; and

providing fluid of a first characteristic to a first of the plurality of fluid inlets.

12. The method of claim 11, wherein the fluid of the first characteristic includes a pigment.

13. The method of claim 11, wherein the fluid of the first characteristic includes a fluorescence material.

14. The method of claim 11, wherein the fluid of the first characteristic includes a phosphorescence material.

15. The method of claim 11, further comprising providing fluid of a second characteristic to a second of the plurality of fluid inlets, wherein the second characteristic is different from the first characteristic.

16. The soft robotic device of claim 1, further comprising a pressure source configured to be in fluid communication with the pressurizing inlet, wherein the pressure source is configured to provide the fluid.

17. The soft robotic device of claim 16, wherein the pressure source includes a microcompressor or a water electrolyzer.

18. A gripping device comprising a plurality of actuatable arms, wherein each of the plurality of actuatable arms includes a soft robotic device of claim 1, wherein the plurality of actuatable arms are configured to bend from a first resting position to a second actuated position upon pressurization.

19. The gripping device of claim 18, wherein the gripping device is configured to lift loads in a range of greater than 80 g and/or of a size that is greater than 1 cm.

20. A method of gripping comprising:

providing a gripping device according to claim 18; and

initiating a series pressurizations and depressurizations that bring the gripping device in gripping contact with a target object.

21. A method of actuation comprising:

providing a soft robotic device according to claim 1; and

providing sufficient pressure to the soft robotic device or the gripping device or the soft robot or the pressurizable network or the soft machine to cause a less stiff wall to expand preferentially, thereby causing the soft robotic device or the gripping device or the soft robot or the pressurizable network or the soft machine to bend around a strain limiting member of the soft robotic device or the gripping device or the soft robot or the pressurizable network or the soft machine.

22. A soft robotic device, comprising:

a flexible molded body comprising a plurality of interconnected pleated chambers, the flexible molded body being comprised of a flexible material and affixed to a strain limiting member in such a manner that the strain limiting member forms a wall of the plurality of interconnected pleated chamber, wherein a thickness of the molded body is at least 1 mm; and

a pressurizing inlet that is configured to receive fluid for the plurality of interconnected pleated chamber,

wherein the plurality of interconnected pleated chambers are configured to preferentially unfold when the flexible molded body is pressurized through the pressurizing inlet, causing bending motion around the strain limiting member; and

wherein the strain limiting member has a wall thickness greater than other portions of the flexible molded body.

23. A soft robotic device capable of extension, comprising:

a flexible molded body having a plurality of interconnected chambers disposed within the molded body; and

a sealing member in a facing relationship with the flexible molded body, wherein the flexible molded body and the sealing member together define a plurality of channels, said channel defined by upper, lower and side walls, and wherein the sealing member is in a state of compression in its resting state and

a pressurizing inlet in fluid communication with the plurality of channels,

the plurality of channels positioned and arranged such that the soft body robotic device expands to relieve the strain in the sealing member when the soft body robotic device is pressurized through the inlet.

24. The soft robotic device of claim 23, wherein the sealing member comprises a strain limiting member and the molded body comprises a plurality of interconnected chambers in facing and sealing relationship with the strain limiting member, wherein the strain limiting member forms a wall of a chamber.

25. The soft robotic device of claim 24, wherein the soft robotic device further comprises a second plurality of interconnected chambers in facing and sealing relationship with the strain limiting member on a face opposite to the first plurality of interconnected chambers.

26. The soft robotic device of claim 23, wherein the sealing member further comprises a reinforcing fiber or fabric.

27. A soft robotic device comprising:

a flexible molded body having a plurality of interconnected chambers disposed within the molded body, wherein a portion of the molded body is comprised of an elastically extensible material and a portion of the molded body is strain limiting relative to the elastically extensible material, and wherein the thickness of the molded body is at least 1 mm; and

a pressurizing inlet that is configured to receive fluid for the plurality of interconnected chambers,

wherein the molded body is configured to preferentially expand when the plurality of interconnected chambers are pressurized by the fluid, causing a bending motion around the strain limiting portion of the molded body,

wherein the molded body is comprised of a single material and the plurality of interconnected chambers comprise at least one wall that is thinner than the strain limiting portion or the strain limiting member.

28. A soft robotic device comprising:

a flexible molded body having a plurality of interconnected chambers disposed within the molded body, wherein a portion of the molded body is comprised of an elastically extensible material and a portion of the molded body is strain limiting relative to the elastically extensible material, and wherein the thickness of the molded body is at least 1 mm;

a pressurizing inlet that is configured to receive fluid for the plurality of interconnected chambers; and

a magnet;

wherein the molded body is configured to preferentially expand when the plurality of interconnected chambers are pressurized by the fluid, causing a bending motion around the strain limiting portion of the molded body.

29. A multi-component soft robot comprising:

a plurality of soft robotic devices according to claim 28; and

a connector having a plurality of fluidic inputs and a pressurizing inlet, wherein the pressurizing inlet is configured to receive fluid, and wherein each of the plurality of soft robotic devices is reversibly attached to one of the plurality of fluidic inputs by a magnetic attractive force.

30. A soft robot capable of locomotion comprising:

a plurality of arms, wherein each of the plurality of arms comprises;

a flexible molded body having a plurality of interconnected chambers disposed within the molded body, wherein a portion of the molded body is comprised of an elastically extensible material and a portion of the molded body is strain limiting relative to the elastically extensible material, and wherein the thickness of the molded body is at least 1 mm; and

a pressurizing inlet that is configured to receive fluid for the plurality of interconnected chambers, wherein the molded body is configured to preferentially expand when the plurality of interconnected chambers are pressurized by the fluid, causing a bending motion around the strain limiting portion of the molded body;

wherein each of the plurality of arms has a gripping surface over which at least a portion of the plurality of arms engages with a terrain; and

a plurality of pressurizing inlets configured to receive pressurized fluid.

31. A soft machine having multiple functionalities, comprising:

a soft robot capable of locomotion according to claim 30 having a first pressurizing inlet, wherein the soft robot is configured to provide locomotion to the soft machine;

a gripping device comprising a plurality of actuatable arms, wherein each of the plurality of actuatable arms includes a soft robotic device, wherein the plurality of actuatable arms are configured to bend from a first resting position to a second actuated position upon pressurization; and

a physical connector disposed between the soft robot capable of locomotion and the gripping device,

wherein the soft robotic device of the gripping device comprises;

a flexible molded body having a plurality of interconnected chambers disposed within the molded body, wherein a portion of the molded body is comprised of an elastically extensible material and a portion of the molded body is strain limiting relative to the elastically extensible material, and wherein the thickness of the molded body is at least 1 mm; and

a second pressurizing inlet that is configured to receive fluid for the plurality of interconnected chambers, wherein the molded body is configured to preferentially expand when the plurality of interconnected chambers are pressurized by the fluid, causing a bending motion around the strain limiting portion of the molded body.

32. The soft machine of claim 31, further comprising a pressure source having a first fluid outlet and a second fluid outlet, wherein the first fluid outlet is configured to be in fluid communication with the first pressurizing inlet, and wherein the second fluid outlet is configured to be in fluid communication with the second pressurizing inlet.

33. The soft machine of claim 31, wherein the physical connector includes a flexible tether.

34. A method of providing locomotion to a soft robot, the method comprising:

providing a soft robot according to claim 30;

providing pressurized fluid to a first pressurizing inlet of the soft robot; and

providing pressurized fluid to a second pressurizing inlet of the soft robot, thereby separately actuating a first arm associated with the first pressurizing inlet and a second arm associated with the second pressurizing inlet.