Compliant microjoint replacements

Contact surfaces in micromechanical pin joints, hinges, and sliders introduce stiction and friction that disrupt motion in micro-electromechanical systems (MEMS). This thesis presents compliant design alternatives that move both in-plane and out-of-plane without introducing contact interference. This document correlates experimental results from fabricated devices to numeric models developed to predict key mechanical responses. The microsystems include the following: • A spiral cantilever spring (shaped like a watch spring) deflects out-of-plane 70% of its largest in-plane dimension. The deflection occurs because of force imparted by injected charge from a scanning electron microscope. • Compliant beams in torsion enable motion that is similar to that of a bushing-style substrate or scissor hinge. • A manual torsion load turns an elastic hoop inside-out as an example of a compliant bistable threshold hinge. • A compliant linkage symmetrically translates in-plane rotary motion to radial motion, similar to a blade aperture mechanism in a camera. These devices exemplify microsystems that avoid failure-inducing surface contact by exploiting an increase in component compliance that occurs as a result of lower bending and torsion stress response in beams with microscale cross-sections.