Evaluation of pneumatic cylinder actuators for hand prostheses

DC motors are currently the preferred actuation method for externally powered hand prostheses. However, they are often heavy and large, which limits the number of actuators that can be integrated into the prosthesis. Alternative actuation methods are being researched, but have not yet found wide application. In this paper, a thin-walled pneumatic cylinder actuator is implemented to move a single-DOF prosthetic hand. Its performance is compared to that of a commercially available DC motor. Both systems are evaluated on speed, responsiveness, and energy capacity. Other properties such as size and mass are also taken into account. While the pneumatic cylinder is capable of high speeds and forces while remaining lightweight, quiet and small, it can prove difficult to control. Improvements to the cylinder design and valve system are recommended, in order to develop the potential of pneumatic cylinder actuators in modern multifunctional hand prostheses.