Redox-induced electricity for energy scavenging and self-powered sensors

With the rapid development of technology in the modern era, the use of energy in different forms and levels has changed due to the numerous electronics devices and sensor systems utilized in society to ensure a smooth and comfortable digital life. In this journey, the use of low-power sensor devices is increasing dramatically due to the toxicity of batteries and conventional energy supply issues. Among the many solutions such as triboelectricity, piezoelectricity, thermoelectricity, and pyroelectricity, redox-induced electricity in energy scavenging and self-powered sensors is considerably appealing. This review presents a concise overview of the latest evolution in redox-based energy generation and the integration of redox-induced electricity generators with sensor devices including device performances. This review focuses on the current trends for energy solutions with alternative and sustainable energy resources such as human fluids, waste heat, thermogalvanic cells, and photoelectrochemistry, which are currently becoming research hotspots. Also, this review will provide a brief discussion about the performance enhancement techniques currently being investigated such as the modification of electrolytes, roles of redox couples, and concentration effects for a broader view to analyze the factors affecting the device output.