An Inchworm Using Levitation Caused by Vertical Vibration

Abstract

SUMMARYWe propose an inchworm-type microactuator which uses levitation caused by vertical vibration. The vertical vibration is generated by a piezoelectric actuator. The inchworm usually consists of thrust elements and clamp elements. The proposed inchworm-type microactuator however does not use any clamp elements. Three levitation elements are connected with two thrust elements which are stacked piezoelectric actuators. The levitation element consists of a mass, a piezoelectric actuator, and a plate. The vertical vibration of the piezoelectric actuator lifts the levitation elements and eliminates the friction. By controlling the phase of the horizontal and vertical piezoelectric actuators, the inchworm moves in a linear direction. The levitation height and the position of the inchworm are measured, and experimental results show the feasibility of the proposed inchworm. The mechanism described in this paper is effective in a precise positioning system in a clean room. C⃝ 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 190(4): 19-25, 2015; Published online in Wiley Online Library (wileyonlinelibrary.com).