Bistable curved-beam actuated by optically controlled Shape Memory Alloy

In this work, a bistable curved-beam is actuated between its two stable states using the force generated by optically controlled SMA elements. Two Shape Memory Alloy (SMA) elements are used for this purpose forming an antagonistic pair. Two laser sources (wavelength equals to 785 nm and 658 nm) are used to heat the SMA active elements in order to induce the martensite to austenite phase transformation in the SMA. The force generated by the SMA sample (3 mm × 1 mm × 100 μm) is measured experimentally using a miniature force sensor which comes out to be 706 mN for 100 mW laser power value. The bistable curved-beam is designed according to these force measurements. At the end, experimental demonstration of the proposed actuation technique is presented.