The Contact Electrification Capability of Amino Acids

Abstract

Triboelectric charging necessitates a frictional contact between two different materials, and contact electrification is typically based on the polarity difference in the triboelectric series. The human skin is a prominent triboelectric material that becomes highly positive during the contact electrification process. However, the reason behind this phenomenon is still remains unrevealed. Herein, we have performed an in-depth analysis of the amino acids present in human skin and quantifying them with regards to triboelectric polarization. The principle focus of this study is based on analyzing those amino acids present in copious amounts in the human skin. The phenomenon of contact electrification is in close relation to the work function and the electron-donating or accepting ability of the material. The standardized experimental as well as computational approaches were employed to analyze the amino acids. Thus, we present an augmented triboelectric series of the amino acids with quantified triboelectric charging polarity by scrutinizing the triboelectric transfer charge, work function, and electron binding energy. Furthermore, a comparison of these properties in the amino acids predominant in the human skin can conclusively render it positive in the series, under contact electrification. The quantification of the triboelectric series may serve as a benchmark for implementing in various applications in the future such as self-powered sensing, or energy harvesting.