Options
2011
Conference Paper
Titel
First results on electrostatic polymer actuators based on UV-replication
Abstract
The miniaturization of actuators results in two major consequences: First, the reduction in efficiency depending on the physical principle. Second, the increasing requirements in positioning accuracy during the assembly and fabrication process in combination with low cost production. Electrostatic polymeric actuators providing out-of-plane motion which can be completely fabricated in parallel fabrication steps and hence be produced on wafer level are compliant to these tolerance and cost constraints. The electrostatic actuation principle is a surface effect and therefore independent of the volume. In addition, the efficiency of electrostatic actuation increases with a decreasing gap size between the electrodes. The simple morphology of such actuators can be easily produced by UV-replication of polymeric materials. In consequence, the electrostatic actuation principle is predestined for the combination with low cost wafer level fabrication. This paper reports on the first results of successfully fabricated electrostatic actuators produced on wafer level. Instead of using a standard silicon substrate our approach is based on the lithographic structuring of the non-conducting material ORMOCER®. In comparison ORMOCER® has a significantly lower elastic modulus (about 1 GPa). Therefore, only a fraction of actuation voltage is necessary for a similar deflection. The material is structured using photolithography and the electrodes are realized with coatings of thin metal layers. Experimental results show a deflection up to 49,1 ?m at 500 V for an 75 ?m thick cantilever beam fixed at both ends. Good agreement between measurements and simulations is achieved, proving the applicability of the software and the assumed material parameters.