The escalating demand for micro/nano-sized devices, such as micro/nano-robots, intelligent portable/wearable microsystems, and implantable medical microdevices, necessitates the expeditious development of integrated microsystems incorporating energy conversion, storage, and consumption. Critical bottlenecks in microscale energy storage/sensors and their integrated systems are being addressed by exploring new technologies and new materials, e.g., MXene, holding great potential for developing lightweight and deformable integrated microdevices. This review summarizes the latest progress and milestones in the realization of MXene-based micro-supercapacitors (MSCs) and sensor arrays, and thus discusses the design fundamentals and key advancements of MXene-based energy conversion-storage-consumption integrated microsystems. Finally, we outline the key challenges in fabricating MXene-based MSCs/sensors and their self-powered integrated microsystems, which is crucial for their practical applications. Particularly, we illuminate viable solutions to such unsolved issues and highlight the exciting opportunities.

Ultracompact and customizable micro-supercapacitors (MSCs) are highly demanded for powering microscale electronics of 5G and Internet of Things technologies. So far, tremendous efforts have been concentrated on fabricating high-performance MSCs; however, compatible fabrication and monolithic integration of MSCs with microelectronic systems still remains a huge challenge taking into full consideration the factors such as electrode film fabrication, high-resolution microelectrode pattern, and electrolyte precise deposition. In this review, we summarize the recent advances of ultrasmall and integrated MSCs with tunable performance and customizable function, including key microfabrication technologies for patterning microelectrodes with superior resolution, precise deposition of customized electrolytes in an extremely small space, and feasible strategies for improving electrochemical performance by constructing thick microelectrodes and special electrode structure. Finally, the related challenges and key prospects of ultracompact and customizable MSCs, including compatible microfabrication methods for electrode materials and films, patterning microelectrodes, customizing shape-conformable electrolytes, performance optimization, and efficient integration with microelectronic systems, are put forward for further promoting their practical application.