Foam Nitinol Torque Tubes As High Power Density Actuators

Shape Change Technologies has demonstrated manufacturable net-shape TiNi foam torque tubes  with  rapid Shape Memory Effect (SME) actuation. The increase in response time on cooling and cycling times is about an order of magnitude better than non-porous TiNi torque tubes with a cost that is projected to also be an order of magnitude less with batch production. Foam TiNi torque tubes with integrated hexagonal ends made attachment simple  to an external structure. TiNi foam torque tubes had sizes ranging from 1.24 to 1.30 cm OD with lengths from 7 to 22 cm long and demonstrated  measured torques of 83 in.lb (9.4 N.m) with fast cycle times of ~ 8s, for a actuator mass of 1.3 oz (38 gms).  A review of measured shape memory effect actuation properties for the torsional actuators is discussed.