A smart material microamplification mechanism fabricated using LIGA

A unique microamplification mechanism formed through the merging of smart material and microelectromechanical system concepts is presented. This microamplification device increases the useful actuation stroke of piezoceramic material through the amplification of piezoceramic strain. The technology demonstrated has utility as a microactuation mechanism for driving micropiezomotors, hearing aid transducers and precision optical switches. The microamplifier, approximately 2000 mu m x 200 mu m x 800 mu m, is composed of electroplated nickel and was constructed using LIGA. An overview of microactuator system requirements and the advantages of scaling the flexure based amplifier illustrates the utility of the new device. The microamplifier is a radically scaled version of a mesoscopic mechanism. An analytical discussion of the operation is presented along with a finite-element analysis of the static and dynamic properties of the microlever. The analytical study is used to develop the operation principles and expected performance of the microamplifier. Experimental static and dynamic testing results are presented that confirm the analytical study. The mechanism has a mean amplification ratio of 5.48, an elastic stroke range of 8 mu m and a fundamental frequency of 82 kHz.