Cilia-based Micro Actuators - Efficient Production of Carbon-Fiber Cilia

Abstract:
Piezoelectric actuators can be based on several basic principles. Ultrasonic actuators accumulate the microscopic amplitudes of a vibrating structure to achieve macroscopic movements. To do so, usually a friction contact is involved. To achieve a principle for lightweight and compact motors this friction contact can be designed to provide an anisotropic friction coefficient. Here, angular carbon fiber cilia can be used as contact layer. To realize the cilia, a plasma etching process in a parallel plate plasma etching machine is used. Samples of uniaxial CFRP are clamped between layers of glass to achieve locally concentrated etching. Cilia of a length of 1 mm can be produced. As the machine has a cylindrical workspace with a diameter of 285 mm and a height of 110 mm, numerous samples can be treated effectively simultaneously. It is clear that the local selectivity of the process has to be improved as the transition zone between untreated fibers still in the epoxy resin matrix and the released cilia is too wide for some applications. Nevertheless, this method allows fast, easy and clean production of carbon fiber cilia in arbitrary geometries for actuation purposes.