Microsized Piston-Cylinder Pneumatic and Hydraulic Actuators Fabricated by Lithography

Future microrobotic applications require actuators that can generate a high actuation force in a limited volume. Up to now, little research has been performed on the development of pneumatic or hydraulic microactuators, although they offer great prospects in achieving high force densities. In addition, large actuation strokes and high actuation speeds can be achieved by these actuators. This paper describes a fabrication process for piston-cylinder pneumatic and hydraulic actuators based on etching techniques, UV-definable polymers, and low-temperature bonding. Prototype actuators with a piston area of 0.15 mm² have been fabricated in order to validate the production process. These actuators achieve actuation forces of more than 0.1 N and strokes of 750 mum using pressurized air or water as driving fluid.