Design and fabrication of electrostatic micro-cantilever array as audible frequency generator

• We designed and fabricated an array of four metallic micro-cantilevers on silicon substrate.
• The working is based on electrostatic effect between the two electrodes.
• An input signal is applied by two ways – (a) Asynchronous actuation and (b) Synchronous actuation.
• Results showed a good agreement with the simulated model for input impulse applied synchronously.
• For asynchronous actuation mode, the result of the as-fabricated device showed a variation.
• The vibrations are generated periodically and the output is very much in the audible frequency range.

In assistive technologies involving voice communication, an audio signal with specific shape is needed. In this regard, the design and fabrication of an electrostatic cantilever array is proposed. An array of four metallic micro-cantilevers with dimensions 650 μm × 200 μm × 0.3 μm is fabricated on the silicon substrate. The working principle is based on the electrostatic effect generated due to a conductive path applied between the electrodes. The results are taken from zinc oxide (ZnO) piezoelectric thin film that allows making contact with the vibrating cantilevers on a specified applied input impulse signals. The results demonstrated the switching action of the cantilevers that depends on the polarity of the input pulses. The results obtained are compared with the FEM based (COMSOL Multiphysics) model that is designed and analyzed prior to the experiment. Further, the experimental results showed a good agreement with the predicted values calculated by the simulated model for the input impulse signal applied synchronously to all the micro-cantilevers. However, for asynchronous actuation mode, the result of the as-fabricated device showed a variation than the simulated results. The vibrations are generated periodically from all the cantilevers and the output shows the resultant signals that are very much in the audible frequency range.