EE Dept  |  ACAE Dept  |  Faculty of Engineering  |  CUHK

Eco-safe Human-motion-powered MEMS Energy Generator for Mobile Electronic Devices This project is funded by the Hong Kong Innovation and Technology Fund (ITS/185/01).

Investigators Introduction Historical Background  Principle & Design Resonation Structure Application Demonstration Infrared Transmission RF Signal Transmission Download Area CMNS Home

Resonation Structure Our previous attempts have been focused on using laser-micromachining to fabricate the copper spring. Laser micromachining is direct and fast, but the cutting resolution may be improved further. We are now developing another process which  involves high-aspect-ration electroplating of copper using lithographic techniques. First of all, a seed layer is sputtered on the silicon wafer. Then, a SU-8 photoresist is coated and baked to form the desired thickness of spring. After that, the SU-8 photoresist is exposed to transfer the desired pattern from the mask to SU-8. The mold for the resonating spring can then be formed after developing the SU-8 photoresist. Then, copper is electroplated on the mold. Finally, the SU-8 photoresist and seed layer are stripped and the desired dimension of copper spring can be obtained. The mold of the resonating spring after the development of SU-8 is shown below.