Articulated MEMS Robot for Microfactory Applications

A MEMS (Micro Electro Mechanical Systems) based four degree of freedom articulated microrobot is presented as an example of next generation miniaturized top down manipulators. The robot occupies 6mm³ in total volume with room for further down scaling. The operating work volume is 50μm × 50μm × 75μm with a 2P2R (Prismatic Prismatic Revolute Revolute) kinematic configuration — X, Y, Pitch and Yaw. The presented microrobot design rises above commonly encountered performance tradeoff’s of previous MEMS positioners such as range of motion vs. exerted force and range of motion vs. precision. It is constructed using a combination of hybrid microassembly and high aspect ratio micromachining. Structurally, the first version of the microrobot consists of Silicon 2 1/2 D parts and a 30μm diameter Cu wire. The robot joints and attachment of the end effector are accomplished by microassembly using compliant snap-fasteners, monolithic flexure joints, and epoxy glue. Actuation is carried out by two banks of in-plane electrothermal actuators, one coupled through an out of plane compliant socket, and the other one coupled remotely using a 30 μm diameter Cu wire. In this paper we present the microrobot kinematic design, and experimental identification of the robot Jacobian. Preliminary experimental characterization of the microrobot shows that it is repeatable to less than 0.5 μm along XY axes and 0.015 degrees along Pitch and Yaw DOFs. Finally, the robot was configured to carry an AFM tip and we demonstrate nano indentation sequences on a Parylene substrate.