Automated Multiprobe Microassembly Using Vision Feedback

This paper describes the algorithm development and experimental results of a vision-guided multiprobe microassembly system. The key focus is to develop the capabilities required for the construction of 3-D structures using only planar microfabricated parts. Instead of using grippers, multiple sharp-tipped probes are coordinated to manipulate parts by using vision feedback. This novel probe-based approach offers both stable part grasping and dexterous part manipulation. The light weight of the part and relatively slow motion means that only kinematics-based control is required. However, probe motions need to be carefully coordinated to ensure reliable and repeatable part grasping and manipulation. Machine vision with multiple cameras is used to guide the motion. No contact force sensor is used; instead, vision sensing of the probe bending is used for the grasp force control. By combining preplanned manipulation sequences and vision-based manipulation, repeatable spatial (in contrast with planar) manipulation and insertion of a submillimeter part have been demonstrated with an experimental testbed consisting of two actuated probes, a passive probe, an actuated die stage, and two cameras for vision feedback.