Abstract: For fully compliant mechanism, the general design method is to estimate all the structure parameters experientially in advance and then analyze its accurate stiffness. It is unavoidable to make amendments on certain parameters in condition that the computed stiffness doesn’t meet the given requirements. And unfortunately, this process depends greatly on one’s experience. Being devoid of systematic theory foundation, the parameter design method is blindfold and difficult to be put into practice. Taking micro-driving displacement amplifier module as example, a closed loop method is presented for design of structure parameters targeting for stiffness. Simplified stiffness model of the micro-driving displacement amplifier module is established through pseudo-rigid-body model method. Every compliant cell’s stiffness can be decided by their geometry relationship and strain energy distributions. And then the parameters of the micro-driving displacement amplifier module will be determined. The FEM program is also developed for parameters design and analysis of this module. For any given precision requirement, the structure parameters can be easily modified based on the software analysis result and the stiffness-parameter relationship model. And then how to obtain the accurate structure parameters targeting for stiffness has realized a kind of closed loop design.

Key words: Closed loop design, Compliant mechanism, Micro-driving, Stiffness