Nitinol Foam Actuators

Shape Change Technologies is unique in exploiting the Shape Memory Effect properties of Nitinol foams.   Using either tube or plate, shape memory properties of the foams have been demonstrated in both lab and commercial settings. 

There are  several key advantages to using TiNi foam actuators  over conventional nitinol wire: 

1. Fast response time: As an open-celled foam, the strut widths determine the thermal response of the material.  Consequently, large diameter foams will have very high forces, but the response time of a small TiNi wire,  allowing fast cycle times and high power densities.
2. Net-shape geometry: Actuator design has  more freedom  with much reduced complexity.
3. Custom Formulations:  We use custom proprietary blends of  Ni and Ti powders  to tailor the transformation temperatures for a specific application.
4. Easy Integration: The ends of the actuator can be designed  for simple and reliable mechanical attachments.   
5. Ganging: Actuators can be ganged together for greater twist.
6. Cost: The cost is significantly less than conventional Nitinol materials.
7. Weight: The weight  is dramatically less than conventional hydraulic actuator counterpart.

For example, an 8" long, 0.625"OD, 0.30" ID  torque tube will provide 25 degrees of twist and 100 in.lb of torque  and weigh 3 oz!
For example, an 200m long,  15mm OD, 12mm ID torque tube will provide 25 degrees of twist and 11 N.m of torque and weighs 60 gms!

Nitinol torque tubes can be made in a variety of sizes and can be ganged together to increase the stroke (angular deflection) of the system. 

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After approximately 250 cycles, the thermomechdnical behavior of a Nitinol foam torque tube stabilizes under a constant mechanical load.