Electrothermal microactuators based on dielectric loss heating

A method for microactuation based on excitation using the heat generated as a result of dielectric loss of materials at high frequencies is presented. This concept has been realized by fabricating electrothermal microactuators, composed of a layer of the copolymer of vinylidene fluoride and trifluoroethylene (PVDF-TrFE), on top of polyimide, using a fully integrated, self-aligned process. These actuators show larger deflection per unit temperature rise than conventional resistively heated electrothermal microactuators due to the properties of the materials used. In addition, they are easy to fabricate, can be remotely excited, and are capable of underwater operation. The actuation mechanism has been verified and a simplified model as well as a finite-element model have been developed. The measured values are in good agreement with those predicted by the model.<
>