Balancing charge dissipation and generation: mechanisms and strategies for achieving steady-state charge of contact electrification at interfaces of matter

Abstract

Static charge generated by contact electrification is a ubiquitous phenomenon. It causes many undesirable consequences in the manufacturing processes of almost all types of industries and our daily lives. On the other hand, the separation of charge by contact electrification has given rise to a diverse variety of novel applications, including harvesting energy for generating electricity and technologies related to sustainability and sensing. However, the phenomena of contact electrification are generally poorly understood. In particular, there is a great need to understand the ways to achieve desired levels of steady-state charge. The steady-state charge achieved by frequent periodic contact electrification is arguably the most important quantity required in continuous operation. This perspective discusses the mechanisms and strategies for obtaining the desired level of steady-state charge at all interfaces of matter, including solid, liquid, and gas. Many studies discussed charge generation, but much less consideration has been placed on another important factor that critically affects the steady-state charge: charge dissipation. We describe the importance of the many fundamental mechanisms of charge dissipation. In addition, we present the factors influencing the mechanisms of charge dissipation (e.g., via a toolbox) and the widespread applications of charge dissipation. The importance of charge dissipation thus indicates that the steady-state charge is a balance between charge generation and charge dissipation. We discuss that different rates of charge generation and charge dissipation are useful in different circumstances. Because the dissipation of static charge generated by contact electrification occurs readily into all interfaces of matter, static is, in fact, highly dynamic in nature.