Wearable, self-locking shape memory alloy (SMA) actuator cartridge

Patent metadata

Field	Value
Publication number	US-10828221-B2
Application number	US-201515518356-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 14, 2014
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

Described embodiments provide a shape memory alloy (SMA) cartridge for use in providing controllable compression. The SMA cartridge includes first and second end caps, each of the first and second end caps being coupled to a passive material. One or more SMA coils extend between the first and second end caps. The SMA coils have a trained state and a deformed state, where the SMA coils are in the deformed state when a stimulus is provided thereto and the SMA coils are in the trained state when the stimulus is removed therefrom. The first end cap and the second end cap include a locking mechanism to automatically lock the first and second end caps in a fixed position relative to one another when the SMA coils are contracted.

First claim

We claim:

1. A shape memory alloy (SMA) cartridge for use in providing controllable compression comprising:
first and second end caps, each of the first and second end caps coupled to a passive material; and
one or more SMA coils extending between the first and second end caps, the SMA coils having a trained state and a deformed state, wherein the SMA coils are in the deformed state when a stimulus is provided thereto and wherein the SMA coils are in the trained state when the stimulus is removed therefrom;
wherein the first end cap and the second end cap comprise a locking mechanism to automatically lock the first and second end caps in a fixed position relative to one another when the SMA coils are contracted.

2. The SMA cartridge of claim 1 , wherein the trained state of the SMA coils comprises a non-contracted state of the SMA coils, and the deformed state of the SMA coils comprises a contracted state of the SMA coils.

3. The SMA cartridge of claim 2 , wherein, when locked, the locking mechanism holds the cartridge in the contracted state if the stimulus is removed.

4. The SMA cartridge of claim 1 , further comprising:
a central spacer disposed between the first and second end caps to hold the one or more SMA coils in a fixed spaced relation to one another in a region between the end caps, wherein the locking mechanism locks the first and second end caps to the central spacer.

5. The SMA cartridge of claim 1 , wherein:
the one or more SMA coils comprise a single SMA coil.

6. The SMA cartridge of claim 1 , wherein:
the one or more SMA coils comprise multiple SMA coils arranged in parallel.

7. The SMA cartridge of claim 1 , wherein:
the first and second end caps each include interface structures for use in coupling each of the first and second end caps to the passive material.

8. The SMA cartridge of claim 7 , wherein the interface structures comprise attachment means configured to couple each of the first and second end caps to the passive material.

9. The SMA cartridge of claim 7 , wherein the interface structures comprise at least one lug and at least one well, the at least one lug configured to be received by a corresponding one of the at least one well, thereby retaining the passive material therein.

10. The SMA cartridge of claim 7 , wherein the passive material comprises a textile material.

11. The SMA cartridge of claim 1 , wherein the passive material comprises one or more hard or semi-hard passive structures.

12. The SMA cartridge of claim 1 , wherein:
the locking mechanism comprises at least one arm having a locking tab disposed thereon, the locking tab configured to engage a corresponding surface of at least one of a central spacer and one of the first and second end caps when the SMA coils are in the contracted state.

13. The SMA cartridge of claim 12 , wherein:
the locking mechanism configured to release, permitting the SMA cartridge to be unlocked from the contracted state.

14. The SMA cartridge of claim 1 , wherein the SMA cartridge comprises a cover enclosing the one or more SMA coils.

15. The SMA cartridge of claim 1 , wherein the SMA cartridge is disposed to form an active seam of a compression garment.

16. The SMA cartridge of claim 15 , wherein the compression garment comprises one of: a bandage, a tourniquet, a mechanical counter-pressure (MCP) space suit, a compressive shirt, compressive pants, a compressive full body suit, and a compressive sleeve configured to receive a body part of interest.

17. The SMA cartridge of claim 15 , wherein the compression garment comprises a tri-axial braid structure.

18. The SMA cartridge of claim 1 , wherein the SMA coil comprises a nickel and titanium (NiTi) alloy.

19. The SMA cartridge of claim 1 , wherein the SMA cartridge comprises at least one material, the at least one material comprising at least one of Acrylonitrile Butadiene Styrene (ABS) and a Fused Deposition Modeling (FDM) thermoplastic.

20. A compression garment comprising:
at least one passive member for surrounding a body part of interest; and
at least one shape memory alloy (SMA) cartridge coupled to ends of the passive member for use in providing controllable compression to the body part of interest, the at least one SMA cartridge comprising:
first and second end caps, each of the first and second end caps coupled to a passive material; and
one or more SMA coils extending between the first and second end caps, the SMA coils having a trained state and a deformed state, wherein the SMA coils are in the deformed state when a stimulus is provided thereto and wherein the SMA coils are in the trained state when the stimulus is removed therefrom;
wherein the first end cap and the second end cap comprise a locking mechanism to automatically lock the first and second end caps in a fixed position relative to one another when the SMA coils are contracted.

21. A method of making a shape memory alloy (SMA) cartridge for use in providing controllable compression, the SMA cartridge comprising first and second end caps configured to be coupled to a passive material and one or more SMA coils extending between the first and second end caps, the first and second end caps comprising a locking mechanism to automatically lock the first and second end caps in a fixed position relative to one another when the SMA coils are contracted, the method comprising:
generating the first and second end caps using at least one material, the first and second end caps having at least one cavity configured to receive the one or more SMA coils;
pausing, at a predetermined point of the generating step, the generating of the first and second end caps and while paused, interlacing the one or more SMA coils into the at least one cavity of each of the first and second end caps; and
resuming and completing the generating step.

22. The method of claim 21 , wherein the step of generating is performed by three-dimensional (3D) printing.

23. The method of claim 21 , wherein the at least one material comprises at least one of Acrylonitrile Butadiene Styrene (ABS) and a Fused Deposition Modeling (FDM) thermoplastic.

24. The method of claim 21 , further comprising:
encasing the one or more SMA coils in the at least one material.

Assignees

• Massachusetts Inst Technology

Inventors

• Holschuh Bradley T
• Newman Dava J
• Gatto Giacomo
• Levrino Luca

Classifications

• A61H2201/165

  Wearable interfaces · CPC title

• A61H1/008 Primary

  Apparatus for applying pressure or blows almost perpendicular to the body or limb axis, e.g. chiropractic devices for repositioning vertebrae, correcting deformation · CPC title

• A61F5/028

  Braces for providing support to the lower back, e.g. lumbo sacral supports · CPC title

• A41D2400/32

  Therapeutic use · CPC title

• A61H2205/10

  Leg · CPC title