Triboelectric-enabled self-powering mechanical antenna

Reciprocity constraints require an antenna to transmit and receive in the same direction, which causes a reduction in efficiency. Recent investigations demonstrate that reciprocity and time-reversal symmetry can be broken through mechanical motion and that asymmetric systems tend to radiate more than symmetric systems. Here, we report a triboelectric-enabled self-powering mechanical antenna (TMA), using the concept of broken symmetry through asymmetric charge distribution and mechanical motion, which significantly enhances radiated fields of the self-powering TMA. Beyond the previously quasi-static and dipole approximation methods, a more universal physical model is established to clarify the fundamental relationships among different physical quantities in a mechanical-driven system through retarded potentials. We anticipate that similar concepts can be utilized not only in the design of new types of MAs but also for applications in energy harvesting and communication technology, as well as studying fundamental implications via, for example, Noether's theorem for Noether conserved quantities.