Design, simulation and testing of micromachined flexible joints.

摘要

This thesis examines the design, simulation and testing of micromachined flexible joints. Micromachined devices or MEMS (Micro-Electro-Mechanical Systems) combine mechanical parts as well as electronic parts on a micro-scale. The objective of this research is to mimic the kinematics of classical macro rotating and sliding joints with flexural micro-joints.; The joints consist of long slender beams that are folded in a variety of shapes: ‘I’, ‘H’, ‘X’, ‘S’, ‘U’ and ‘V’ shaped joints are considered. Finite element simulations are used to calculate in-plane rotational, axial and lateral stiffness, out-of-plane rotational stiffness and examine the effect of variations in joint length and beam angles.; The simulation results are compared to a series of dynamic tests of polysilicon micromachined joints. The resonant frequencies of joint-mass systems are measured using a non-contacting laser reflectance system and the derived experimental in-plane rotational stiffnesses are found to agree with simulations.; Design guidelines for the selection of the best suited joint shape and length for given functional requirements such as directional stiffness, selective compliance, and range of motion are presented. Two examples of joint use in planar micro-mechanisms are given.