Force-controllable, optically driven micromachines fabricated by single-step two-photon microstereolithography

We have fabricated optically driven micromechanisms and demonstrated their motion under optical force. All of the movable microcomponents are directly fabricated through an assembly-free process using the high-speed scanning of a femtosecond laser focused inside a photocurable resin. Since these movable micromachines are made from photocurable resin transparent to visible and near-infrared light, they can be driven by the force of optical trapping. We demonstrate a simple, versatile method for driving movable micromachines. Part of the movable component is optically trapped by a single laser beam and manipulated according to the desired trajectory. Various types of motion, including rotation and swinging are demonstrated. In addition, the optically driven micromachines can be force-controlled to femtonewton order by adjusting the position trapped by the laser beam. We demonstrated the femtonewton order force-controllable swing motion of micromanipulators. A microturbine was rotated by circular scanning of a trapping laser beam in a liquid. Such force-controllable optically driven micromachines are promising manipulation tools for biomolecules such as DNA and protein.