A Battery‐Less Arbitrary Motion Sensing System Using Magnetic Repulsion‐Based Self‐Powered Motion Sensors and Hybrid Nanogenerator

This work introduces a battery-less arbitrary motion sensing system by integrating a magnetic repulsion-assisted self-powered motion sensor with a hybrid nanogenerator (MRSMS–HNG). The device detects motion parameters of a moving object in any direction and simultaneously converts low-frequency vibrations (<5 Hz) into electricity. The system uses repulsive forces between magnets to achieve self-powered sensing.

• Integration of a self-powered motion sensor with a hybrid nanogenerator (MRSMS–HNG).
• Use of magnetic repulsion to actuate side magnets for self-powered arbitrary motion sensing.
• High sensitivity for both linear motion and tilting angle detection.
• Demonstration of a real-time, battery-less wireless motion sensing system.

The device uses a central magnet for the EMG-TENG hybrid generator and four side magnets for motion sensing, all aligned in the same magnetization direction. The repulsive force from the central magnet's movement actuates the side sensors. The system's sensitivity and power output were measured, and its capability was demonstrated by wirelessly transmitting sensor data to a smartphone.

The self-powered motion sensors exhibit a high sensitivity of 981.33 mV g⁻¹ for linear motion and 9.83 mV deg⁻¹ for tilting angle. The EMG and TENG deliver peak powers of 27 mW and 56 µW, respectively. The system successfully demonstrated real-time wireless transmission of motion data, realizing a battery-less solution for autonomous control applications.