Gramian-based optimal design of a dynamic stroke amplifier compliant micro-mechanism

This paper presents a new method developed for the optimal design of microrobotic compliant mechanisms. It is based on a flexible building block method, called Flexln, which uses an evolutionary approach, to optimize a truss-like structure made of building blocks. From the first design step, in addition to conventional mechanical criteria, dynamic gramian- based metrics can be considered in the optimization procedure to fit expected frequency responses of the synthesized mechanisms. A planar monolithic compliant coupling structure is obtained by the optimal design method to act as a stroke amplifier for piezoelectric stacked actuators, to operate in both static and dynamic motions, and to passively filter out undesirable vibrations. Finally, performance comparisons between some of the pseudo-optimal Flexln synthetized compliant mechanisms demonstrate the interests of the proposed optimization method for the design of dynamic operating smart microrobotic structures.