Current and future developments in artificial muscles using electroactive polymers.

For decades, electroactive polymers received relatively little attention due to their limited actuation capability. However, in the last 15 years, a series of electroactive polymer materials have emerged that produce a significant shape or size change in response to electrical stimulation. These materials have the closest functional similarity to biologic muscles, enabling the engineering of novel capabilities that were, up until recently, impossible to achieve. Efforts are underway to address the many challenges that are hampering the practical application of these materials, and recent progress has already led to dramatic capability improvements. Various novel mechanisms and devices were demonstrated including robotic fish, catheter steering elements, robotic arms, miniature grippers, loudspeakers, active diaphragms, Braille display and dust-wipers. For developers of future medical devices, these materials are offering numerous advantages for their flexibility, fracture toughness and controllability, as well as low mass and low power requirements. This article provides a review of the current status, challenges and potential near-future applications of these materials.