Non-uniform residual stresses for parallel assembly of out-of-plane surface-micromachined structures

This note describes a method for the parallel self-assembly of out-of-plane surface-micromachined structures that uses non-uniform residual stresses, inherent in many surface-micromachining processes. The residual stresses are used to achieve a one-time only actuation capable of lifting and assembling raised structures. Theory is provided to calculate the deflection and stiffness of bi-layer cantilevers. Devices for amplifying the vertical deflection are demonstrated and used to assemble large arrays of devices.