Out-of-plane micro-force function generator based on polymeric thermal actuators for modifying micro-deformation

Abstract

Many micro-electro-mechanical multilayered structures are always subject to residual stress and cause deformation easily. The induced mechanical deformation will directly affect the performance of these devices. To improve the performance, this deformation should be controlled or eliminated. This letter proposed an out-of-plane micro-force function generator by employing polymer SU-8 thermal actuators array to modify the out-of-plane micro-deformation. The electro-thermal actuator tends to have relatively large displacement in actuation direction at low driving voltage (reaching as high as 2.94 μm in actuation direction at 6 V), and this proposed micro-force function generator is able to achieve accurate modifying of out-of-plane micro-deformation.

Arrayed SU-8 polymer thermal actuators with inherent real-time feedback for actively modifying MEMS’ substrate warpage

“…In recent years micro-electro-mechanical systems (MEMS) have continuously evolved towards increased functionality, thinner die and higher performance, and therefore reliability problems caused by thermal/mechanical stresses have become a critical issue [1,2]. These micro-fabricated structures are fragile and sensitive to stresses as a result of fabrication variation and environmental interruption [3,4], especially for those with thinner die and fixed anchors, which will cause structural parameters that deviate from the desired design value [5][6][7][8].…”