No abstract

Self-powered devices are becoming increasingly important with the development of portable electronics in the context of the energy crisis. An emerging flexible self-powered system that can spontaneously and immediately transform energy from the ambient environment into electric energy has been developed, this system has considerable societal and commercial applications.Here, a flexible self-powered device is demonstrated on the basis of the streaming potential mechanism, in which H 2 plasma is used to implement a gradient distribution of an oxygenated group and then enhance streaming potential in graphene oxide membrane (GOM). The effects of processing time, environmental conditions, and device structure on the performance of output energy are investigated in detail. The device is capable of rapidly outputting voltage up to ∼290 mV with a maximum output power of 5.22 μW/cm 2 within 3−4 min in different liquid environments. Furthermore, the self-powered device is stable and durable through device cycle and material durability tests. To prove the streaming potential mechanism further, COMSOL software is used to simulate the power generation process of GOM. The results show that the simulation results agree well with the experimental ones. The present work offers a different approach for the processing of flexible GOM self-powered devices, providing a high reference value for future related studies on materials for flexible devices applied to the portable self-powered field.

For decades, the rapid development of wireless communication has provided people a smarter way of living. However, a significant increase in electromagnetic pollution is an unavoidable consequence. Evading radar detection in modern warfare has also become an important prerequisite for survival on the battlefield. This review provides a comprehensive overview of the current status and types of electromagnetic absorption metamaterials, especially their design and preparation methods. Moreover, this review focuses on the strategies used to optimise the absorber absorption performance. Finally, this review presents a viewpoint on future research on electromagnetic absorption metamaterials, the main challenges that need to be addressed and the possible solutions.