| Summary: | 碩士 === 國立交通大學 === 電控工程研究所 === 98 === Energy scavenging from ambient environment becomes feasible to power independent remote sensors or portable devices due to low power VLSI and CMOS technology development. The requirement of power consumption has been reduced to a few tens of microwatts. Micro-Electro-Mechanical System (MEMS) is a platform that integrates mechanical devices with electric circuit. The development of MEMS is increasingly popular in the world. By using MEMS technology, a mechanical energy harvester with electric component is capable of supplying those low power devices.
In this thesis, the novel design and modeling method as well as the fabrication and measurement of a DC capacitive vibration-to-electric energy converter are introduced. With the device area constraint of 1 , bias by a 3.6V battery, output voltage limited to 40V, and operation frequency of 120Hz, the optimum output power is 40.5uW and 0.87uW for devices with and without a 4 gram external mass attachment, respectively.
The device was fabricated in SOI wafers with deep silicon etching technology. Compared with previous devices, LPCVD nitride improved the isolation of fingers. Gold pads and switch lateral coverage defined by the high precision shadow mask had reduced the aluminum oxidation problem and reduced the leakage resistance. The resonant frequency measured by a shaker agreed with our design value. Variable capacitance of 94pF to 485pF was measured. The parasitic resistance was improved from 103M omhto 156M?mh?| The mechanical contact switch was test and workable. However, due to non vertical combs fingers, lower voltage was generated in the conversion process. The output power measurement is still in progress.
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