Improvement of micro mobile machine with piezoelectric driving force actuator

As a micromachine driving force generation mechanism, a pin-type actuator, made up of a piezoelectric bimorph plate with a contact pin to generate the 2-dimensional driving force, has been studied with the aim of miniaturization. Miniaturized pin-type actuators with bimorph plate size of 6.5 mm/spl times/6.5 mm and 5 mm/spl times/5 mm have been prepared, and their fundamental performances were examined to estimate the micro characteristics. Also, the micro mobile machine in tube has been improved so as to set the driving circuit into the machine body and its performances have been also evaluated. Vibrational analysis of a pin-type actuator with a size of 26 mm/spl times/26 mm has been performed by finite element analysis with the piezoelectric coupling effect. As a result, the superposition of natural vibrational modes with the phase difference appears to generate the directional driving force at the contact pin tip.