Fiber-reinforced actuator

Patent metadata

Field	Value
Publication number	US-9835184-B2
Application number	US-201414457086-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Aug 10, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A fiber reinforced actuator includes first and second sets of fibers coupled with and arranged along a control volume to controllably constrain mobility of an actuator body. Fibers of the first set can be arranged with respect to fibers of the second set and with respect to a central axis to impart the actuator with various combinations of torsional and axial force responses. A third fiber may be included to form a helical actuator. A plurality of actuators can be coupled together for coordinated movement, thereby providing additional mobility directions, such as trans-actuator bending. The fiber-reinforced actuators and actuator assemblies are potential low cost, low energy consumption, lightweight, and simple replacements for existing motion devices such as servo-motor driven robots.

First claim

The invention claimed is:

1. A fiber-reinforced actuator, comprising:
a body having a control volume, the body extending for a length along a central axis of the control volume;
a first set of fibers coupled with the body, the fibers of the first set extending along the body at an angle α relative to the central axis; and
a second set of fibers coupled with the body, the fibers of the second set extending along the body at an angle β relative to the central axis;
wherein the fibers of said first and second sets of fibers are exclusive of the control volume and are configured to constrain movement of the body in response to work performed on the control volume to cause the actuator to predictably change in shape or effective rigidity when said work is performed on the control volume,
wherein the actuator exhibits a response that includes a moment about the central axis when said work is performed on the control volume, and
wherein α≠±β, and the orientation of the fibers of the first and second sets of fibers meets one of the following criteria:
−90°>α>90° and −90°>β>90°; or
α=90° and β≠0.

2. The fiber-reinforced actuator as defined in claim 1 , wherein α≠0 and β≠0.

3. The fiber-reinforced actuator as defined in claim 1 , wherein α≠90° and β≠90°.

4. The fiber-reinforced actuator as defined in claim 1 , wherein α≠±β, and the orientation of the fibers of the first and second sets of fibers meets the following additional criteria:

α
≠

cot

-
1

⁡

[

-
1

2
⁢

⁢

cot
⁡

(
β
)

]

.

5. The fiber-reinforced actuator as defined in claim 1 , wherein α≠±β, and the orientation of the fibers of the first and second sets of fibers meets the following additional criteria only when −90°<β<0:

-
90

⁢
°

<
α
<

cot

-
1

⁡

[

-
1

2
⁢

⁢

cot
⁡

(
β
)

]

.

6. The fiber-reinforced actuator as defined in claim 1 , wherein α≠±β, and the orientation of the fibers of the first and second sets of fibers meets the following additional criteria only when −90°<β<0:

cot

-
1

⁡

[

-
1

2
⁢

⁢

cot
⁡

(
β
)

]

<
α
<

90
⁢

°
.

7. The fiber-reinforced actuator as defined in claim 1 , wherein the body comprises an elastomeric tube.

8. The fiber-reinforced actuator as defined in claim 1 , wherein the central axis is non-linear when the actuator is in a free state.

9. The fiber-reinforced actuator as defined in claim 1 , wherein the fibers of the first and second sets of fibers are at least partially embedded in the body.

10. The fiber-reinforced actuator as defined in claim 1 , wherein the control volume is a volume of fluid.

11. The fiber-reinforced actuator as defined in claim 10 , wherein the fluid comprises a gas.

12. A fiber-reinforced actuator assembly comprising a fiber-reinforced actuator as defined in claim 1 coupled together with at least one other fiber-reinforced actuator for coordinated movement.

13. The fiber-reinforced actuator assembly as defined in claim 12 , wherein respective control volumes of each fiber-reinforced actuator of the assembly are selectively interconnected with each other in series.

14. The fiber-reinforced actuator assembly as defined in claim 12 , wherein the fiber-reinforced actuators are coupled together in parallel.

15. A fiber-reinforced actuator assembly comprising two or more fiber-reinforced actuators as defined in claim 1 coupled together for coordinated movement.

16. The fiber-reinforced actuator as defined in claim 1 , wherein at least one fiber comprises a shape memory alloy.

17. The fiber-reinforced actuator as defined in claim 1 , further comprising an additional fiber extending along the control volume at any angle other than α or β.

18. The fiber-reinforced actuator as defined in claim 1 , wherein at least one of the angles α or β changes along the length of the body.

19. A fiber-reinforced actuator, comprising:
a body having a control volume, the body extending for a length along a central axis of the control volume;
a first set of fibers coupled with the body, the fibers of the first set extending along the body at an angle α relative to the central axis; and
a second set of fibers coupled with the body, the fibers of the second set extending along the body at an angle β relative to the central axis;
wherein

Assignees

• Univ Michigan Regents

Inventors

• Bishop-Moser Joshua
• Krishnan Girish
• Kota Sridhar

Classifications

• F15B2215/305

  characterised by the use of special materials · CPC title

• F15B15/10 Primary

  the motor being of diaphragm type · CPC title