Direct Laser Writing of Multishaped VO 2 Microactuators Based on Freestanding VO 2 Film

Abstract Microactuators that convert external stimuli such as heat, light, current, and magnetic field into mechanical motion are essential components in microelectro‐mechanical systems. To date, microactuators have been fabricated mainly using conventional microfabrication technologies and inorganic thin films, but although such technologies facilitate the mass production of microdevices, they are expensive and lack flexibility when either preparing only a few devices or facing special needs. Laser‐direct‐writing is an effective complement to microfabrication, but is seldom used in the construction of inorganic microactuators. In this work, a laser‐direct‐writing technique on the freestanding vanadium dioxide (VO 2 ) film for fabricating microactuators with arbitrary shapes is developed. The precision of the laser direct writing attained 2 µm under ultralow pulse energy of 52 pJ. The pulse energy is two orders of magnitude lower than that needed for patterning VO 2 film and other semiconductor materials on substrates. The overall performance of the resulting VO 2 microactuators is comparable with that of those fabricated by conventional microfabrication technologies, but the fabricating efficiency and flexibility are increased. Such a fabrication strategy can also be used to fabricate other smart microdevices, such as strain sensors and photodetectors.