Abstract
We made
dextrous tweezers which consist of two 1 DOF compliant fingers perpendicular to
each other. Here we call them ortho-tweezers. Strain gauges were used to
monitor the deflections, forces and part rolling angle. The ortho-tweezers are
dextrous and robust in manipulation of submillimer-sized parts, even without
closing a sensing loop. The ortho-tweezers by themselves can pick-and-place and
roll parts. With help of a few fixtures on a 3 DOF Cartesian stage, the
ortho-tweezers can reliably pivot and regrasp the part by continually applying
contact forces which greatly exceed micro-scale adhesion forces. By measureing
contact moments on the part through strain gauges, we can tell whether the part
is aligned with a wall. For the demonstration of these techniques, a structure
was made by bonding micro-parts using UV-glue. By arranging a bunch of
miniaturized ortho-tweezers, it could also be possible to operate parallel
assembly with only one XYZ Cartesian stage.