研究採用近場靜電場紡絲（(Near Field Electrospinning Technology, NFES）技術製造一新穎自電式應變感測器，並應用於結構型變即時監測。自電式應變感測器由聚偏二氟乙烯 (PVDF) 纖維、PDMS固定基板、鋁金屬和奈米銀線(Nano Silver Wire, AgNWs)組成。 其中PVDF 纖維使用 NFES技術紡絲而成，其直徑約為8μm，楊氏係數1.1GPa，壓電效應可達230mV。固定基板是將PDMS通過熱固化製成而成透明薄膜，並利用EHD作為感測器電極，再與PVDF結合成為自電式應變感測器。因此，本論文自電式應變感測器的X光繞射 β值達到2112，靈敏度比商用應變感測器增加20%，再整合角度累積演算法，則可量測物體在單位時間內角度變化量或累積物體在運動期間全程位移量，突破傳統的PVDF感測器僅能單次量測物體型變的限制。經由實驗證明，自電式應變感測器搭配角度累積演算法，角度量測範圍為-35°至+35°，量測精度為5°，在拍打頻率為240Hz時，拍打力量為27.68gw且連續120分鐘後，其壓電效應僅衰減9%，應用於監測結構安全，達到連續量測結構的變化，改善商用壓電感測器只能單次感測的現況。未來自電式應變感測器將具備即時連續量測之能力，將可實現壓電感測器用於長時間監測結構型變之技術。

This study uses the near-field electrospinning (NFES) technology to make a novel self-powered strain sensor and applies it to the real-time monitoring of bending structure, so that the measurement equipment can be reduced in volume. A self-powered strain sensor consists of polyvinylidene difluoride (PVDF) fibers, a PDMS fixed substrate, and aluminum electrode. PVDF fibers are spun with DMSO and acetone using NFES technology, with the diameter of about 8μm, Young's modulus of 1.1GPa, and piezoelectric effect of up to 230mV. The fixed substrate is a film made of PDMS by thermal curing and adhered to the PDMS film surface of the sheet Al metal as an Al electrode, and then combined with PVDF-fiber film, to become a self-powered strain sensor. Thus, the XRD β value of the self-powered strain sensor reaches 2112, the sensitivity is increased by 20% over the traditional strain sensor, and the cumulative angle algorithm measure the angular change of the object over a unit time or the cumulative displacement of the object over the entire period of motion. The Experimental results demonstrate that the self-powered strain sensor combined with angle accumulation algorithm is applied to monitor the ship structure, achieve continuous measurement of ship structure changes, and improve traditional piezoelectric sensors can only be sensed once. In future, self-powered strain sensors will have the ability to continuously measure in real time, enabling the use of piezoelectric sensors for long-term monitoring of structural techniques.

[1]J. Curie, and P. Curie, “Développement par compression de l'électricité polaire dans les cristaux hémièdres à faces inclinées,” Bulletin de minéralogie, vol. 3, no. 4, pp. 90-93, 1880.
[2] VERGARA, Andrea, et al. PZT MEMS Actuator with Integrated Buried Piezoresistors for Position Control. In: 2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE. pp. 626-629. 2021.
[3] T. Hou, X. Zhou, Y. Xin et al., “Screen-Printed Parallel-Stripes Electrodes Toward Oriented Piezoelectric Nanofibers Sensors for Both Stability and Sensitivity Improvement,” IEEE Sensors Journal, vol. 21, no. 21, pp. 23898-23902, 2021.
[4] W. E. Teo, and S. Ramakrishna, “A review on electrospinning design and nanofibre assemblies,” Nanotechnology, vol. 17, no. 14, pp. R89, 2006.
[5] G. Gilbert, De magnete, magneticisque corporibus, et de magno magnete tellure; Physiologia nova, plurimis & argumentis, & experimentis demonstrata: Petrus Short, 1967.
[6] J. F. Cooley, "Apparatus for electrically dispersing fluids," Google Patents, 1902.
[7] G. I. Taylor, “Electrically driven jets,” Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, vol. 313, no. 1515, pp. 453-475, 1969.
[8] S. Yang, Z. Wang, Q. Kong et al., “Varicose-whipping instabilities transition of an electrified micro-jet in electrohydrodynamic cone-jet regime,” International Journal of Multiphase Flow, vol. 146, pp. 103851, 2022.
[9] M. M. Nazemi, A. Khodabandeh, and A. Hadjizadeh, “Near-Field Electrospinning: Crucial Parameters, Challenges, and Applications,” ACS Applied Bio Materials, 2022.
[10] D. H. Kang, and H. W. Kang, “Advanced electrospinning using circle electrodes for freestanding PVDF nanofiber film fabrication,” Applied Surface Science, vol. 455, pp. 251-257, 2018.
[11] G. Zheng, J. Jiang, X. Wang et al., “High-aspect-ratio three-dimensional electrospinning via a tip guiding electrode,” Materials & Design, vol. 198, pp. 109304, 2021.
[12] J. Luo, L. Zhang, T. Wu et al., “Flexible piezoelectric pressure sensor with high sensitivity for electronic skin using near-field electrohydrodynamic direct-writing method,” Extreme Mechanics Letters, vol. 48, pp. 101279, 2021.
[13] Z. Liu, C. Pan, L. Lin et al., “Direct-write PVDF nonwoven fiber fabric energy harvesters via the hollow cylindrical near-field electrospinning process,” Smart materials and structures, vol. 23, no. 2, pp. 025003, 2013.
[14] A. Sadaf, M. Elter, D. Mager et al., “Wall Microstructures of High Aspect Ratio Enabled by Near‐Field Electrospinning,” Advanced Engineering Materials, pp. 2101740, 2022.
[15] G. Wang, T. Liu, X.-C. Sun et al., “Flexible pressure sensor based on PVDF nanofiber,” Sensors and Actuators A: Physical, vol. 280, pp. 319-325, 2018.
[16] Z. Guo, Y. Hu, X. Hu et al., "In-situ polarization enhanced high-sensitivity acoustic locating and recognition sensor based on flexible PVDF-TrFE film array." pp. 403-406.
[17] H. Chen, L. Zhou, Z. Fang et al., “Piezoelectric Nanogenerator Based on In Situ Growth All‐Inorganic CsPbBr3 Perovskite Nanocrystals in PVDF Fibers with Long‐Term Stability,” Advanced Functional Materials, vol. 31, no. 19, pp. 2011073, 2021.
[18] L. Shi, H. Jin, S. Dong et al., “High-performance triboelectric nanogenerator based on electrospun PVDF-graphene nanosheet composite nanofibers for energy harvesting,” Nano Energy, vol. 80, pp. 105599, 2021.
[19] B. Lin, Z.-T. Li, Y. Yang et al., “Enhanced dielectric permittivity in surface-modified graphene/PVDF composites prepared by an electrospinning-hot pressing method,” Composites Science and Technology, vol. 172, pp. 58-65, 2019.
[20] S. Zhang, C. Ge, and R. Liu, “Mechanical characterization of the stress-strain behavior of the polydimethylsiloxane (PDMS) substate of wearable strain sensors under uniaxial loading conditions,” Sensors and Actuators A: Physical, vol. 341, pp. 113580, 2022.
[21] Y. Jiang, L. Liu, L. Chen et al., “Flexible and stretchable dry active electrodes with PDMS and silver flakes for bio-potentials sensing systems,” IEEE Sensors Journal, vol. 21, no. 10, pp. 12255-12268, 2021.
[22] R. Luo, X. Li, H. Li et al., “A stretchable and printable PEDOT: PSS/PDMS composite conductors and its application to wearable strain sensor,” Progress in Organic Coatings, vol. 162, pp. 106593, 2022.
[23] Sim, Sangjun, et al. "Vertically-Aligned Carbon Nanotubes-Embedded PDMS Microstructures For Flexible Tactile Sensor Array with High Sensitivity and Durability." 2022 IEEE 35th International Conference on Micro Electro Mechanical Systems Conference (MEMS). IEEE, 2022.
[24] C. Ma, Y.-F. Liu, Y.-G. Bi et al., “Recent progress in post treatment of silver nanowire electrodes for optoelectronic device applications,” Nanoscale, vol. 13, no. 29, pp. 12423-12437, 2021.
[25] Yu, Xuecheng, et al. "A stretchable and transparent triboelectric nanogenerator based on prestretching PDMS with silver nanowires as electrode." 2019 20th International Conference on Electronic Packaging Technology (ICEPT). IEEE, 2019.
[26] J. Li, Y. Tao, S. Chen et al., “A flexible plasma-treated silver-nanowire electrode for organic light-emitting devices,” Scientific reports, vol. 7, no. 1, pp. 1-9, 2017.
[27] X. Li, G. S. Lee, S. H. Park et al., “Direct writing of silver nanowire electrodes via dragging mode electrohydrodynamic jet printing for organic thin film transistors,” Organic Electronics, vol. 62, pp. 357-365, 2018.
[28] S. Ahn, Y. Cho, S. Park et al., “Wearable multimode sensors with amplified piezoelectricity due to the multi local strain using 3D textile structure for detecting human body signals,” Nano Energy, vol. 74, pp. 104932, 2020.
[29] X. Ran, C. Wang, Y. Xiao et al., “A portable sitting posture monitoring system based on a pressure sensor array and machine learning,” Sensors and Actuators A: Physical, vol. 331, pp. 112900, 2021.
[30] Y. Su, L. Zheng, D. Yao et al., “Robust physiological signal monitoring by a flexible piezoresistive sensor microstructured with filamentating laser pulses,” Sensors and Actuators A: Physical, vol. 331, pp. 112907, 2021.
[31] R. Seethaler, S. Z. Mansour, M. G. Ruppert et al., “Position and force sensing using strain gauges integrated into piezoelectric bender electrodes,” Sensors and Actuators A: Physical, vol. 321, pp. 112416, 2021.
[32] Z. Yang, Z. Zhu, Z. Chen et al., “Recent Advances in Self-Powered Piezoelectric and Triboelectric Sensors: From Material and Structure Design to Frontier Applications of Artificial Intelligence,” Sensors, vol. 21, no. 24, pp. 8422, 2021.
[33] S. K. Ghosh, and D. Mandal, “Bio-assembled, piezoelectric prawn shell made self-powered wearable sensor for non-invasive physiological signal monitoring,” Applied Physics Letters, vol. 110, no. 12, pp. 123701, 2017.
[34] Y. Dai, J. Chen, W. Tian et al., “A PVDF/Au/PEN multifunctional flexible human-machine interface for multidimensional sensing and energy harvesting for the Internet of Things,” IEEE Sensors Journal, vol. 20, no. 14, pp. 7556-7568, 2020.
[35] P. Huang, S. Xu, W. Zhong et al., “Carbon quantum dots inducing formation of β phase in PVDF-HFP to improve the piezoelectric performance,” Sensors and Actuators A: Physical, vol. 330, pp. 112880, 2021.
[36] Z.-H. Liu, C.-T. Pan, Z.-Y. Ou et al., “Piezoelectricity of well-aligned electrospun fiber composites,” IEEE Sensors Journal, vol. 13, no. 10, pp. 4098-4103, 2013. [2] VERGARA, Andrea, et al. PZT MEMS Actuator with Integrated Buried Piezoresistors for Position Control. In: 2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS). IEEE. pp. 626-629. 2021.