Electroactive polymers: An emerging technology for MEMS

Electroactive polymer (EAP) transducers are an emerging technology with many features that are desirable for MEMS devices. These advantages include simple fabrication in a variety of size scales, and ruggedness due to their inherent flexibility. Dielectric elastomer, a type of EAP transducer that couples the deformation of a rubbery polymer film to an applied electric field, shows particular promise because it can produce high strain and energy density, high efficiency and fast speed of response, and inherent environmental tolerance. A variety of proof-of-principle dielectric elastomer actuator configurations have been demonstrated at the small size scales needed for MEMS devices, including rolled "artificial muscle" actuators for insect-inspired microrobots, framed and bending beam actuators for efficient opto-mechanical switches, diaphragm and enhanced-thickness-mode actuators for microfluidic pumps, and valves and arrays of diaphragms for haptic displays. Several challenges remain for EAPs, including integration with driving electronics, and operational lifetime.