[17p-A37-7~11] 16.2 Energy Harvesting

3:45 PM - 4:00 PM JST(6:45 AM - 7:00 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[17p-A37-8] High Efficient Piezoelectric Nanogenerators with TiO₂-NFs-Doped P(VDF-TrFE) Copolymers via Ultrviolet Thermal Annealing

〇(D)TzuChuan Yang¹, TzuWei Hsu¹, TingHan Lin¹, MingChung Wu^1,2, JerChyi Wang^1,2,3 (1.Chang Gung Univ., 2.Chang Gung Memorial Hospital at Linkou, 3.Ming Chi Univ. of Tech.)

Keywords:

P(VDF-TrFE),Piezoelectric nanogenerator,Ultrviolet Thermal Annealing

Poly(vinylidene fluoride–trifluoroethylene) (P(VDF-TrFE))-based piezoelectric nanogenerators (PENGs) have been considered as promising self-powered devices owing to their excellent flexibility, easy fabrication, and lightweight. P(VDF-TrFE) can form α-, β-, and γ-phase crystallinities depending on its molecular arrangement via thermal annealing, where β-phase displays the best piezoelectric properties due to the well-aligned C-F bonds. In this study, a novel crystallization process for P(VDF-TrFE) copolymers was proposed. TiO₂-nanofibers (TiO₂-NFs) were first doped into P(VDF-TrFE), and then the thermal annealing was performed with ultrviolet (UV) light exposure to assist dipole alignment (Fig. 1(a)), which was called ultraviolet thermal annealing (UTA). In Fig. 1(b), the characteristic peaks at 475, 840, 1288, and 1400 cm^-1 corresponding to β-phase crystallinity of P(VDF-TrFE) in FTIR spectra were obtained for the significant enhancement of the sample under the UTA with an UV light exposure at 20 mW/cm² (UTA-20). In the SEM image (Fig. 1(c)), the needle-like-shaped P(VDF-TrFE) can be observed, confirming the β-phase crystallinity. For the PENG measurement (Fig. 1(d)), a maximum output voltage of approximately 4 V was observed in the UTA-20 sample. To investigate the power density of PENGs, different load resistances were in series with the device to measure the output voltage (Fig. 1(e)). The maximum power density of 35 mW/m² was calculated via the formula of P=V²/R for the sample with a 1-MΩ load resistor. In summary, the TiO₂-NFs-doped P(VDF-TrFE) showed a significant enhancement in β-phase formation for both FTIR and SEM under a 20-mW/cm² UTA treatment and a superior output performance of the PENGs was demonstrated, providing a brilliant future for the development in self-powered devices.