本論文為利用近場電紡織技術，製作與研究壓電奈米纖維發電機，並且改良及比較壓電纖維的電紡織生產技術效率，主要重點為(1)利用近場電紡織技術可控制單根壓電奈米纖維排列特性製造奈米發電機，並且設計串聯與並聯兩種不同電極排列方式的基板(2)奈米發電機量測與應用，(3)藉由泡棉材料的多孔特性改良傳統電紡織技術的生產效率。(1)利用近場電紡織技術製作壓電奈米纖維發電機利用近場電紡織與電極圖形設計製作高電壓輸出的壓電奈米發電機。使用纖維狀的壓電高分子材料製造的奈米發電機具有高能量轉換效率且穩定輸出，故本章學生以直寫(direct-write)方式將壓電高分子PVDF（聚偏氟乙烯）沉積在可撓性基底上製作PVDF的奈米發電機。並且設計一個簡單但效果良好的電壓和電流疊加電極基板。(2)奈米發電機量測與應用同時把PVDF奈米纖維陣列串聯和並聯的條件下，製作完成的奈米發電機能夠產生約1.7 V電壓和300nA電流的峰值輸出。這一成果將原本過去只有單根壓電奈米纖維的電壓和電流輸出大幅度增加。此外學生將奈米發電機的交流輸出進行整流，顯示了儲能和充電應用的技術可行性。並且針對發電機的穩定性與人體應用分別進行測試。(3)藉由泡棉材料的多孔特性改良傳統電紡織技術的生產效率本章研究內容為改良傳統電紡織技術之生產效率。學生以不同尺寸的多孔材料作為電紡織噴嘴的裝置，取代過去僅有單一噴嘴的設計。且使用10％的PVDF（聚偏氟乙烯）和7％的PEO（氧化聚乙烯）高分子溶液分別作為提高生產率實驗的材料作為驗證。該電紡織生產方式(藉由泡棉材料)可以在相對較低的電壓（DC6〜7KV）下生產大量奈米纖維。實驗結果顯示，每單位面積的射流數為85〜150 jets/cm2，比傳統的單一噴嘴高一到兩個數量級。This thesis mainly research fabrication of nanogenerator, piezoelectric technology and application in electrospinning. The focus of the study is (1) Fabrication of nanogenerator via near-field electrospinning process, (2) Measurement and application of nanogenerator, (3) High-Throughput production of nanofibrous mats via a porous materials electrospinning Process.(1)A Facile Electrode Pattern for Voltage and Current Superposition of Near-field Electrospun Piezoelectric Nanogenerator–Fabrication and DesignHarvesting energy from human motion in a routine exercise is a promising and viable approach for powering a wide range of wireless mobile electronics in our daily life. Direct-write piezoelectric polymeric nanogenerator is robust and high energy conversion efficiency such that tiny physical motions/disturbances over human operation frequencies can be stimulated and energy scavenged. Here, we demonstrate a direct-write polymeric poly (vinylidene fluoride) PVDF nanogenerator on the flexible substrate and a simple scaling-up electrode design for easy superposition of both voltage and current. (2) A Facile Electrode Pattern for Voltage and Current Superposition of Near-field Electrospun Piezoelectric Nanogenerator-Measurement and ApplicationThe nanogenerators fabricated using arrays of PVDF nanofibers in parallel and in serial configurations which are capable of producing a peak output voltage of ~1.7 V and the current reached up to 300nA. This achievement is two order of magnitude increases in both voltage and current output compared with conventional near-field setup for only one electrospun nanofiber. In addition, the alternating current output of the nanogenerator is rectified and demonstrates the technological feasibility for energy storage and recharging applications. This work shows a practical and versatile technique of using direct-write electrospun nanogenerators for powering mobile and wireless microelectronic devices. (3)High-Throughput Production of Nanofibrous Mats Via a Porous Materials Electrospinning Process A facile method is presented for the electrospinning of multiple polymer jets into nanofibers. The experiments in this study electrified 7 wt% PEO (polyethylene oxide) and 10 wt% PVDF (polyvinylidene fluoride) solutions and adopted porous materials(bars with various dimensions) to enhance the productivity of the electrospinning process. The proposed electrospinning mechanism can be used to mass produce nanofibers at a relatively lower voltage (D.C. 6~7 kV) and obtain a remarkable increase in throughput. The experimental results showed that the jets per area were on the order of 85~150jets/cm2, which is one to two orders of magnitude higher than the conventional single needle electrospinning process and can easily surpass the magnetic needleless method by a factor of 3.3 to 5.8. The proposed method of using porous materials as electrospinning devices (nozzles) should contribute to the advancement of next-generation, large-scale electrospinning systems for nanofiber fabrication.
