Laser-Induced Microsphere Hammer-Hit Vibration in Liquid

We demonstrate a new principle of the laser-induced hammer-hit vibration of a micron-sized black sphere in liquid glycerol with a single divergent Gaussian beam. The light-induced Δα-photophoretic force, which is significantly improved by the vibrating speed of the microparticle, is responsible for both the pushing and pulling force of the hammer-hit vibration. Our approach expands the optical manipulation of microparticle hammer-hit vibration to a liquid medium and provides full control over the trapped particles, including the adjustment of the vibration frequency, amplitude, and position.