Folding assembly of micro-actuators

A muscle-inspired linear actuator that combines many piezoelectric micro-actuator “cells” into a single functional unit is designed and fabricated via folding assembly technique. A bow-shaped epoxy beam structure amplifies the very small displacement of a thin film lead zirconate titanate (PZT) beam, generating a large orthogonal contractive displacement of 15.24 μm in a footprint of 515 μm. Then, three sets of three actuator cells are assembled out of plane by folding about thin gold hinges connecting each set. With the folded triplet array, an unblocked displacement of 5.16 μm and blocking force of 6.31 μN were obtained.