Abstract
We propose and demonstrate the autonomous tweezers driven by surface tension without any actuators. The tweezers are composed of only a pair of the polydimthylsiloxane (PDMS) cantilevers having different wettability. Since the front and back surfaces of the cantilevers have different wettability, they can bend due to the difference of surface tension and hydrostatic pressure exerted on each surface when they come in contact with the surface of liquid. Using this self-bending phenomenon, we succeed in not only grasping but also releasing a floating object under proper conditions. The autonomous tweezers will be useful for damage-less manipulation of biological samples without any actuators and external energy source.
