A number of materials have been explored for their use as artificial muscles. Among these, dielectric elastomers (DES) appear to provide the best combination of properties for true muscle-like actuation. DES behave as compliant capacitors, expanding in area and shrinking in thickness when a voltage is applied. Materials combining very high energy densities, strains, and efficiencies have been known for some time. To date, however, the widespread adoption of DES has been hindered by premature breakdown and the requirement for high voltages and bulky support frames. Recent advances seem poised to remove these restrictions and allow for the production of highly reliable, high-performance transducers for artificial muscle applications.