The Piezoionic Effect : Biomimetic Transduction Mechanism for Sensing, Actuation, Interface, and Energy Harvesting

The transduction from mechanical to electrical signal or energy, and vice versa, has wide applications spanning wearable electronics, medical devices, human-machine interfaces, prosthetics, synthetic biology, soft robotics, augmented reality (AR), internet-of-things (IoT), smart cities, environmental monitoring, energy conversation, and energy harvesting. Although many biological processes such as those in sensory receptors and cell communication uses ions, much of existing artificial intelligent sensory and processing systems operate based solely on electrons as signal or energy carriers. Therefore, the realization of natively ionic devices can significantly advance the frontiers of both capabilities and applications. This invited paper introduces the piezoionic effect, surveying the historical evolution, scientific description, methodology, application, future outlook, and current debates. This work complements existing ones in that it is an in-depth analysis of key attributes of the piezoionics field but, unlike a conventional review, does not emphasize the categorization of individual works, though is also provided. This work is also aimed at facilitating the understanding and evaluation of the piezoionics field in terms of its key capabilities, promises, fundamental limitations, technical challenges, and practical applications. Piezoionics as a biomimetic mechanical-electrical transduction mechanism is expected to grow rapidly. Through in-depth analysis and working out implications for the future, it is hoped that this paper provides a foundation for further exploration, discussion, and collaboration across different fields. The community looks forward to the piezoionic effect evolving into a mainstream paradigm for the ubiquitous realization of sensors, actuators, interfaces, as well as energy harvesters and beyond. © 2023 The Authors. ChemElectroChem published by Wiley-VCH GmbH.