A self-powered droplet sensor based on a triboelectric nanogenerator toward the concentration of green tea polyphenols

We developed a simple, three-layered and self-powered liquid droplet sensor based on a triboelectric nanogenerator. The current sensitivity of the self- powered sensor reaches −40.12 μA mg mL −1 , and the voltage sensitivity reaches −0.195 V μg mL −1 .