A flexible and smart shape memory alloy composite sheet based on efficient and bidirectional thermal management

Leveraging advances in shape memory alloys (SMAs) and flexible thermoelectric devices (f-TEDs), this paper presents a structural and functional integrity composite sheet to address the inefficient and bulky activation of 2-D SMAs. A series of experimental tests were performed to reveal the generation, change, and transfer mechanisms of different types of electrically-induced heat in the f-TED, as well as the temperature-induced SMA phase transformation behaviors. The results show that the composite sheet exhibited good bidirectional thermal management capacity. The austenite deformation can be completed within 10s at an operating current of 2 A. The cooling recovery, in particular, performs much better than in conventional modes (the temperature declines exponentially with time). Finally, through two functional prototypes, a light switch and a flexible gripper, the application potential of the proposed composite was further experimentally demonstrated.