Maeda Mahato, Taguchi Dai, Manaka Takaaki
Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
J Phys Chem Lett. 2024 Dec 19;15(50):12269-12273. doi: 10.1021/acs.jpclett.4c03044. Epub 2024 Dec 5.
By using in situ optical second-harmonic generation (SHG) measurement, dynamical changing of polar molecular orientations caused by mechanical rubbing of polyimide triboelectric generators is observed. The polar orientational order is enhanced during rubbing, which relaxes with the time constant τ = 7.1 s. Analysis of s- and p-polarized SHG intensity under s-polarized laser incidence showed that molecules align along the rubbing direction with the tilt angle θ = 51° from the surface normal. By using the obtained time constant and the tilt angle, the output power in the - measurement is discussed. That is, the SHG result gives a theoretical maximum power of 2.0 μW/cm, while the effective power observed in the - measurement is 0.26 μW/cm, suggesting that merely part of produced power is received at external loads. The in situ SHG measurement gives helpful ways to discuss the power output of triboelectric generators using polar materials.
通过使用原位光学二次谐波产生（SHG）测量，观察到聚酰亚胺摩擦电发电机机械摩擦引起的极性分子取向的动态变化。在摩擦过程中极性取向顺序增强，并以时间常数τ = 7.1 s弛豫。在s偏振激光入射下对s偏振和p偏振SHG强度的分析表明，分子沿摩擦方向排列，与表面法线的倾斜角θ = 51°。利用获得的时间常数和倾斜角，讨论了测量中的输出功率。也就是说，SHG结果给出的理论最大功率为2.0 μW/cm，而在测量中观察到的有效功率为0.26 μW/cm，这表明在外部负载下仅接收了部分产生的功率。原位SHG测量为讨论使用极性材料的摩擦电发电机的功率输出提供了有用的方法。
