The finding of droplet-based electricity generator (DEG), based on the moving boundary of electrical double layer, has triggered great research enthusiasm, and a breakthrough in instantaneous electric power density was achieved recently. However, the dynamic mechanism for such droplet-based electricity generators remains elusive, impeding optimization of the DEG for practical applications. Through comprehensive experiments, we developed a dynamic model of surface charge density that can explain the underlying mechanism for the DEGs. The spreading droplet in touch with the top electrode can be equivalently regarded as an additional part of the top plate of the DEG capacitor, and the change of droplet area causes the change of surface charge density of the plates, driving electrons to migrate between the two plates. The insight of the dynamic mechanism paves a way for optimal design and practical applications of DEGs
@article{arxiv.2009.05932,
title = {Dynamics for droplet-based electricity generators},
author = {Xiang Wang and Sunmiao Fang and Jin Tan and Tao Hu and Weicun Chu and Jun Yin and Jianxin Zhou and Wanlin Guo},
journal= {arXiv preprint arXiv:2009.05932},
year = {2020}
}