Parallel Microassembly with Electrostatic Force Fields

Assembly is a fundamental issue in the volume production of products that include microscopic (submillimeter) parts. These parts are often fabricated in parallel at high density but must then be assembled into patterns with lower spatial density. In this paper we propose a new approach to microassembly using 1) ultrasonic vibration to eliminate friction and adhesion, and 2) electrostatic forces to position and align parts in parallel. We describe experiments on the dynamic and frictional properties of collections of microscopic parts under these conditions. We rst demonstrate that ultrasonic vibration can be used to overcome adhesive forces; we also compare part behavior in air and vacuum. Next, we demonstrate that parts can be positioned and aligned using a combination of vibration and electrostatic forces. Finally, we demonstrate part sorting by size. Motivated by these feasibility experiments, our goal is a systematic method for designing implementable planar force elds for microassembly based on part geometry. Although arti cial potential elds are wellknown, to our knowledge this is the rst attempt to systematically design physical potential elds for manipulation.