Flexible robotic actuators

Patent metadata

Field	Value
Publication number	US-9506455-B2
Application number	US-201414329506-A
Country	US
Kind code	B2
Filing date	Jul 11, 2014
Priority date	Jan 19, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

Some embodiments of the disclosed subject matter includes a laminated robotic actuator. The laminated robotic actuator includes a strain-limiting layer comprising a flexible, non-extensible material in the form of a sheet or thin film, a flexible inflatable layer in the form of a thin film or sheet in facing relationship with the strain-limiting layer, wherein the inflatable layer is selectively adhered to the strain-limiting layer, and wherein a portion of an un-adhered region between the strain-limiting layer and the inflatable layer defines a pressurizable channel, and at least one fluid inlet in fluid communication with the pressurizable channel. The first flexible non-extensible material has a stiffness that is greater than the stiffness of the second flexible elastomeric material and the flexible elastomer is non-extensible under actuation conditions.

First claim

The invention claimed is:

1. A laminated robotic actuator comprising:
a strain-limiting layer comprising a flexible, non-extensible material in a form of a sheet or thin film;
a sealing layer comprising a flexible, non-extensible material in a form of a thin film or sheet in a facing relationship with the strain-limiting layer, wherein a stiffness of the strain-limiting layer is greater than a stiffness of the sealing layer, wherein the sealing layer is selectively adhered to the strain-limiting layer, and wherein a portion of an un-adhered region between the strain-limiting layer and the sealing layer defines a pressurizable channel; and
at least one fluid inlet, in fluid communication with the pressurizable channel, configured to receive pressurized fluid to cause the actuator to bend toward the sealing layer.

2. The laminated robotic actuator of claim 1 , further comprising an adhesive layer disposed between the strain-limiting layer and the sealing layer, wherein the adhesive layer is shaped to selectively adhere the sealing layer to the strain-limiting layer to define the channel.

3. The laminated robotic actuator of claim 1 , wherein one of the strain-limiting layer and the sealing layer is coated with an adhesive, and further comprising a masking layer disposed between the strain-limiting layer and the sealing layer, wherein the masking layer defines a shape of the un-adhered region between the strain-limiting layer and the sealing layer.

4. The laminated robotic actuator of claim 1 , wherein the strain-limiting layer comprises the adhesive coating.

5. The laminated robotic actuator of claim 1 , wherein the channel comprises a plurality of interconnected chambers configured to provide a twisting motion of the laminated robotic actuator upon pressurization of the channel via the fluid inlet.

6. The laminated robotic actuator of claim 1 , wherein the channel comprises a plurality of interconnected chambers configured to provide a bending motion of the laminated robotic actuator upon pressurization of the channel via the fluid inlet.

7. The laminated robotic actuator of claim 1 , wherein a stiffness of the strain-limiting layer is configured to determine a physical strength associated with the laminated robotic actuator upon pressurization of the channel via the fluid inlet.

8. The laminated robotic actuator of claim 1 , wherein the channel comprises a plurality of interconnected chambers configured to provide two different motions of the laminated robotic actuator upon pressurization of the channel via the fluid inlet.

9. The laminated robotic actuator of claim 1 , further comprising a reinforcing structure for providing additional physical support to the laminated robotic actuator.

10. The laminated robotic actuator of claim 1 , further wherein the channel comprises a plurality of sub-channels that are independently coupled to the at least one fluid inlet, thereby enabling independent pressurization of the sub-channels.

11. The laminated robotic actuator of claim 1 , wherein the channel comprises a plurality of interconnected chambers arranged along a curved central flow conduit.

12. A twisting actuator comprising a laminated robotic actuator of claim 1 , wherein the pressurizable channel comprises a central flow conduit and a plurality of slanted branches, and the slanted branches are at an acute angle with respect to a central axis of the actuator to determine a twisting motion of the actuator.

13. The twisting actuator of claim 12 , wherein the central axis is aligned with the central flow conduit.

14. A lifting robot comprising a laminated robotic actuator of claim 1 , wherein the pressurizable channel comprises radial channels arranged in a concentric manner about a central point of the laminated robotic actuator, and connecting channels perpendicular to the radial channels, wherein the radial channels are configured to deflect away from a surface of the strain-limiting layer upon pressurization.

15. A robot comprising a plurality of actuatable arms, wherein one of the plurality of actuatable arms includes a laminated robotic actuator of claim 1 .

16. The robot of claim 15 , wherein the robot comprises 2, 3, 4, 5, 6, 7, 8 or more actuatable arms.

17. The robot of claim 15 , wherein one or more of the plurality of actuatable arms is configured to be actuated independently.

18. A gripping device comprising a plurality of actuatable arms, wherein each of the plurality of actuatable arms includes a laminated robotic actuator 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 comprises 2, 3, 4, 5, 6, 7, 8 or more actuatable arms.

20. The gripping device of claim 18 , wherein one or more of the plurality of actuatable arms is configured to be actuated independently.

21. A method for providing a flexible robotic actuator, comprising:
providing a strain-limiting layer having a substantially two-dimensional layer of a first flexible material, wherein the strain-limiting layer is non-extensible;
providing a sealing layer having a substantially two-dimensional layer of a second flexible material, wherein the sealing layer is non-extensible, and the strain-limiting layer is stiffer compared to the sealing layer;
determining a shape of a region at which the sealing layer is to be adhered to the strain-limiting layer; and
adhering the sealing layer to the strain-limiting layer based on the shape of the region, thereby forming a channel for fluid communication having the shape that, upon receiving pressurized fluid, causes the actuator to bend towards the sealing layer.

22. The method of claim 21 , further comprising providing an adhesive layer between the strain-limiting layer and the sealing layer, wherein the adhesive layer is shaped to selectively adhere the sealing layer to the strain-limiting layer to define the channel.

23. The method of claim 21 , further comprising providing a masking layer disposed between the strain-limiting layer and the sealing layer, wherein the masking layer defines a shape of the un-adhered region between the strain-limiting layer and the sealing layer.

24. A method of actuating a laminated soft robotic comprising:
providing a laminated soft robotic according to claim 1 ; and
initiating a series of pressurizations and depressurizations that actuate the laminated soft robotic to provide a predetermined motion.

25. The method of claim 24 , wherein the series of pressurization and depressurizations provide a sequence of two or more predetermined motions.

26. A method of gripping comprising:
providing a plurality of laminated robotic actuators according to claim 1 ; and
initiating a series of pressurizations and depressurizations that bring the actuators in gripping contact with a target object.

27. The method of claim 26 , further comprising initiating a series pressurizations and depressurizations to perform a walking motion.

28. The method of claim 24 , wherein the pressure of the fluid applied to the channel via the fluid inlet is selected to provide a predetermined range of a motion.

Assignees

• Harvard College

Inventors

• Mazzeo Aaron D
• Morin Stephen A
• Shepherd Robert F
• Whitesides George M
• Kalb William B

Classifications

• B25J9/142

  comprising inflatable bodies · CPC title

• F15B15/103

  using inflatable bodies that contract when fluid pressure is applied, e.g. pneumatic artificial muscles or McKibben-type actuators · CPC title

• F03G7/0612

  using polymers · CPC title

• F03G7/0616

  characterised by the material or the manufacturing process, e.g. the assembly (magnetic shape memory alloys F03G7/06147) · CPC title

• B25J9/1075 Primary

  with muscles or tendons · CPC title