Light-driven microcantilever actuator based on photoenhanced magnetization in a GaAs-Fe composite film

Using the recently discovered phenomenon of photoenhanced magnetization in GaAs–Fe semiconductor-ferromagnet composite films [S. Haneda, S. Koshihara, and H. Munekata, Physica E 10, 437 (2001)], we have demonstrated a light-driven microactuator. It consists of a GaAs–Fe/GaAs(100) chip glued onto a 4.3 mm long, 2.1-μm-thick Si cantilever. A deflection of 0.7 μm was achieved when the cantilever was illuminated with 650 nm, 713 μW laser light in a magnetic field of 1.7 T at room temperature.