Assembly Guidelines for High Performance Meso-Flexure Linkage Mechanisms

Flexure mechanism systems with ultra-high precision motion are increasingly being used for several applications including micro-measurement, micro/nano manipulation, microfabrication, data reading, writing on CD, and so on. Flexure linkages offer inherent advantages of being frictionless, highly repeatable, and having great design flexibility. Monolithic fabrication of these mechanisms limits use of multiple materials in the system and becomes expensive especially for three dimensional mechanisms. Alternative method of assembling various components of flexure mechanism is considered in this paper. Assembly guidelines for building flexure mechanisms from separately machined components are arrived at. It is found that if each of the fixed ends of the flexure mechanism is located perfectly using two pins, internal stresses are generated in the linkages and their warping does not allow the desired operation. The proposed guidelines which are based on criterion similar to Grubler’s include a very simple formulation to determine number of location pins to be used in assembly. Further guidelines are laid down to determine locations of these pins. Two flexure mechanisms, one planar and other 3D based on double parallelogram flexure linkage mechanisms are fabricated and assembled using these guidelines and found to be working with repeated assembly and disassembly.