A smart microrobot on chip: design, identification, and control

This paper deals with the microrobot on chip (MOC) concept which corresponds to the development of compact, inexpensive, and easily "plug and use" microrobotic components (as it is the usual case with electronic chips). A first prototype of a 6 degrees-of-freedom (DOF) piezoelectric micromanipulator MOC (MMOC) illustrates this concept: one scanning piezostage can move the gripper in x-y axes and the piezoelectric microgripper itself has two y-z DOF per finger. An embedded optical fiber connected to a CCD camera and a force self-sensing system allowing force feedback. The first prototype of MMOC is electrically and mechanically connected to a smartcard reader. In order to be able to manipulate safely and accurately micro-objects, a force/position closed-loop controller is proposed taking into account the static and dynamic behavior of the microgripper. Hysteresis compensation is obtained through Preisach model and then an adaptive inverse control method is employed for open-loop control strategy. Numerical and experimental results which validate the theoretical developments are presented.