Comparison of two seal technologies for hydraulic microactuators

In order to improve the power density of microactuators, recent research focuses on the applicability of fluidic power at microscale. One of the reasons that hydraulic actuators are still uncommon in micro system technology is due to the difficulty of fabricating powerful microseals. This paper presents two seal technologies that are suitable for sealing small-scale hydraulic actuators. Measurements on prototype actuators show that force densities up to 0.45 N/mm² (0.025 N/mm³) and work densities up to 0.2 mJ/mm³ can easily be achieved with the developed seal technology. These characteristics can still be improved as the maximum driving pressures of the actuators have not yet been determined.