Parallel microrobot actuated by capillary effects

Abstract

This paper presents a new actuation mean for a parallel microrobot based on capillary effect, combining surface tension and pressure effects. The device presented is a compliant moving table having 6 degrees of freedom (dof) among which three are actuated: z axis translation having a stroke of a few hundreds of microns, and θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> and θ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> tilt angles up to about 15°. The structure is immersed in a liquid and the actuation principle is based on fluidic parameters (pressure and volume). A model to calculate the stiffness of the system is presented and validated by experimental measurements. Some issues inherent to this type of actuation are also addressed. The presented device is an illustration of a promising solution for microrobotic actuation using capillary effects in a liquid media.