A comparison of muscle with artificial actuators

'Artificial' actuator technologies under development include shape memory alloys, piezoelectric actuators, magnetostrictive actuators, contractile polymers and electrostatic actuators. The relevant properties of muscle are outlined and compared with a variety of artificial actuators. These and other actuators, such as regular and superconducting electromagnetic motors, internal combustion engines, hydraulic motors, pneumatic actuators, are reviewed and compared with muscle elsewhere (see Hunter, 1990; Hollerbach et al., 1991).>