Theoretical Increase in the Electric Force Exerted on Body Hair Owing to Superimposed Electric Fields with Optimized AC/DC Ratios

Abstract

The biological effects of direct current (DC) and extremely low frequency (ELF) electric fields (EFs) have not been completely clarified. However, scholars have proposed that body hair movement on the body surface in the EFs triggers these effects. The electric forces in DC or alternating current (AC) EFs have been discussed, and a theoretical equation has been proposed, which considers either AC or DC EFs only. In contrast, superimposed EFs combining DC and AC EFs, inducing changes in the electric force, are widely used in the industry. In this regard, the biological effects of the EFs could be understood better by considering the superimposed conditions. This study generalizes a theoretical equation to include the superimposed EFs and calculate the electric force change acting on body hair with respect to the AC/DC ratio. The results show that the electric force that is acting on body hair changes with the AC/DC ratio of the superimposition, even when the total root mean square value is constant. Moreover, there is an optimal ratio for maximizing the electric force. This study could provide insights for an in‐depth understanding of the biological effects of EFs if the results of the developed equation are studied in conjunction with the actual effects. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.