結合無線傳輸之複合PVDF/PTFE布基摩擦起電元件的研製

Abstract

摩擦起電器(Triboelectric generator, TEG)是藉由物理性接觸，將機械能轉換為電能輸出。然而，目前多數的摩擦起電器主要是使用金屬與ITO薄膜作為電極材料，這些材料的可撓性較差使得摩擦起電器的應用受到侷限，故本論文使用市售的導電布料當作電極，並使用聚偏二氟乙烯(Polyvinylidene difluoride, PVDF)與聚偏二氟乙烯/聚四氟乙烯(Polytetrafluoroethylene, PTFE)作為摩擦層，實現製作簡單、低成本、高可撓性，且尺寸為40 × 40 mm2的單電極式布基摩擦起電元件。研究結果顯示使用75 µm 之PVDF/PTFE作為摩擦層的元件，透過CF4電漿進行表面改質處理，具有最佳的開路電壓與短路電流，分別為28.41 V與0.32 μA。此外，也針對元件的作動頻率與施力大小對輸出特性進行探討，發現作動頻率越高對於輸出特性明顯的提升，而作動元件之外力逐漸增加也能使輸出特性提升，但當施力達8 N以上輸出會趨近穩定。最後，本研究也評估負載阻抗對電壓與電流的影響，並進一步證明當負載阻抗為50 MΩ時，可得到的最大功率為12.91 μW。此外，經由耐久性的測試，證實本論文發展的元件之性能在20000次循環還保有14.2 V電壓輸出。最後，用手拍打元件可將18顆串聯的綠光LED燈泡點亮，證明本研究之元件確實可以當作自供電微型發電機來使用。另外，為了達成無線傳輸與感測的應用，也透過橋式整流器、分壓電路及藍芽無線模組，將布基摩擦起電元件所感測的電壓訊號經過Arduino控制板處理後，傳輸至電腦或手機中進行即時顯示，證明其未來具有應用於無線傳輸功能感測領域的潛力。Triboelectric generators (TEGs) use simple physical contact to convert mechanical energy into electrical output. However, most of the TEGs mainly use metal and ITO films as electrode materials. These materials without high flexibility will limit the application of the TEGs. Therefore, this study uses commercially available conductive fabrics as electrodes, and uses polyvinylidene difluorid (PVDF) and polyvinylidene difluorid / polytetrafluoroethylene (PTFE) surfaces with pyramid array structure as the friction layers, to achieve simple production, low cost, high flexibility single-electrode-mode fabric-based triboelectric devices with the size of 40 × 40 mm2.The results show that the fabric-based triboelectric device using PVDF/PTFE surfaces with pyramid array structure as the friction layer has the best open circuit voltage and short circuit current output after CF4 plasma surface modification treatment, which are 28.41 V and 0.32 μA respectively. We also discussed in terms of devices actuation frequency and applied force. It is found that the higher the actuation frequency, the output voltage and output current increases significantly, and the gradual increase of the applied force can increase the output performance, but when the force reaches 8 N or more, the output will tend to be stable.Evaluated the effect of load resistance on the output voltage and current, and further learned that when the load resistance is 50 MΩ, the maximum power is 12.91 μW. Durability resistance tests also confirmed that the device still retains 14.2V even after 20,000 cycles. On palm tapping the device, 18 green LEDs connected in series can be lit up.The Bluetooth wireless module and bridge rectifier are also used to process the voltage signals sensed by the device, which can be wirelessly transmitted to a computer or mobile APP for instant transmission, proving that it has the potential to be applied to the field of wireless transmission function sensing in the future.