應用磁-機-電耦合技術所建構之微型獵能器

Abstract

近年來無線感測器網路(Wireless Sensor Networks, WSN)迅速發展，應用也越來越廣泛，雖然使用無線感測器網路能節省大量的人力物力，但也伴隨著電源充電/更換的問題，使其無法長期穩定運作。能從環境中擷取能源並永續運作的獵能器(Energy Harvester)成為無線感測器網路電源問題的最佳解決方案。 本論文應用磁能、機械能、電能互相轉換之磁-機-電耦合技術，開發針對環應中振動能與磁能的獵能器。本論文所開發之獵能器以尺度來分，可分為釐米級與微米級，以能量轉換機制來分，可分為磁力式與磁電式。在釐米尺度，分別開發出單軸、三維、與三軸磁力式獵能器，並應用變頻技術提升元件的輸出功率，其中，三軸磁力式變頻獵能器可輸出300 mV的電壓。在磁電式機制亦成功製作並測試釐米磁電式獵能器，可產生474 mV的電壓輸出。在微米尺度，應用微機電製程技術，製作Ni/PZT層狀複合結構的振動獵能器，同時具有磁力/磁電複合式兩種能量轉換機制，並已成功量測出元件在交流磁場環境下的輸出訊號。

In recent years, wireless sensors network (WSN) have developed rapidly and been used in various applications. Although using wireless sensors network can save a lot of manpower and resources, the numerous sensors in the network cause a battery-charging/replacement issue. This would be impractical for some WSN applications. To address this issue, energy harvesters which can harness the energy from the environmental vibration and subsequently convert the energy into the electricity in order to power the WSN become an alternative energy solution. Therefore, in this thesis, novel energy harvesters utilizing a magneto-mechanical-electric coupling are conceived and developed to harness the environmental vibration as the alternative energy solution. The conceived and developed energy harvesters are divided into two categories: millimeter-scale and micrometer-scale (or magnetic-force-driven and magnetoelectric-based). In the millimeter-scale, single-axial, three-dimensional, and three-axial magnetic-force-driven energy harvesters are demonstrated. In addition, frequency-up conversion technology is utilized by these energy harvesters to enhance the power output. The experimental results show the voltage output/response of the three-axial magnetic-force-driven energy harvester and millimeter-scale magnetoelectric-based energy harvester is up to 300 mV and 474 mV, respectively. In micro-scale, a Ni/PZT laminated energy harvester fabricated by MEMS technology is demonstrated to harness the energy by utilizing both magnetic-force-driven and magnetoelectric-based approaches (i.e., hybrid approach). The testing result shows the Ni/PZT laminated energy harvester successfully harness the energy from an environmental AC magnet field.