VEH device band widening by multifrequency arrangement as energy source of electronic sensors

Development of new electronic devices and Smart sensors at remote locations are increasing day by day. Due to remote locations, it is difficult to provide conventional energy source. Vibration energy harvesting(VEH) is source to such electronic devices. VEH is power source for MEMS, working on electromagnetic energy conversion principal. VEH devices gives maximum output at its resonance frequency. But if excitation frequency is varying, maximum output is not obtained. Multi-frequency device having sub devices of different frequencies can be used. Device working band widen is possible by combining induced emf of each sub device. This paper present three sub devices of natural frequency 10 Hz, 12.5Hz and 15.5 Hz. Distance between two magnets affects in repulsive and attractive force. Three devices are arranged with axis of oscillation coinciding each other. This paper studies repulsive arrangement of adjacent sub VEH systems. As distance between subsystems reduces, repulsive force increases. This affect behavior of systems. Different experiments have conducted to study effect of distance between sub VEH systems. Also output of sub systems connected in series with different combinations and total output voltage is studied. It has been found that 2 mm distance between sub system 1 and 2, 14mm distance between subsystem 2 and 3 is giving constant output of 10.5V in range 8-17Hz. So vibration energy harvesting band can be increased by multifrequency arrangement.