Opto-Microactuator With Low-Thermal-Conductivity Material by Laser Heating

A laser opto-microactuator is proposed in this paper. The effects of the thermal-conductivity of actuator materials on rotational phenomena are discussed. The actuator with 4 flat blades made of aluminum or Pyrex glass plate was installed in a vacuum chamber. By molecular gas dynamics effects, the actuator is rotated with the irradiation of argon ion laser beam. The blade surfaces of the actuator were coated by carbon black powder for absorbing laser beam power and heating the surfaces. Just after irradiating one blade surface of the actuator by the laser, the macroscopic gas flow is induced around the actuator at non-zero Knudsen number. By the reaction of the induced flow the actuator can rotate. This is the molecular gas dynamics effects (1)(2). The rotational rate of the actuator with Pyrex glass blades is faster than that of the actuator with aluminum blades. Because Pyrex glass has about 200 times or more of lower thermal-conductivity than that of the aluminum, then Pyrex glass blades maintain a lager temperature difference between front and rear surfaces and a large molecular gas dynamics effects. Also irradiating to the glass surface, Pyrex glass rotor can rotate counter-clock-wise of irradiating to carbon-coated surface.