Photothermal Microactuators Fabricated by LIGA Technology

A novel microactuator based on photothermal expansion is introduced, which is actuated by laser beam eliminating external circuit. The mechanism of the photothermal expansion is theoretically analyzed, and the working principle of a U-shaped photothermal microactuator with two arms is introduced and the lateral deflection is calculated. LIGA technology involving X-ray lithography and electroplating is introduced to fabricate photothermal microactuators. The fabrication process with LIGA technology is introduced and important details such as X-ray mask and electroplating are discussed. Photothermal microactuators with different structures are fabricated by LIGA technology at Beijing Synchrotron Radiation Facility (BSRF) and tests are carried out with laser beam. The deflection of a V-shaped photothermal microactuator of Ni material can reach 25.8 μm under the control of a 1064 nm, 800 mW laser and a U-shaped can reach about 11 μm at an 808 nm, 600 mW laser.