Harvesting Vibration From Rotating Machinery as a Power Source for a Wireless Sensor Node

The wireless sensor device which uses battery can cause problems when the wireless nodes are large in number and when the nodes are placed in the difficult area to access. Therefore, it is advantageous for the sensor node to be capable of extracting energy from the environment, making it self-powered, self-sustaining and lowering overall cost of the wireless network. Improvement in integrated circuit (IC) technology has made the overall power consumption of circuit very small which leads to a very promising application of the vibration-based energy harvester micro power generator (VEHM). This paper discusses on some practical design considerations in harvesting vibration from rotating machinery to power up a wireless sensor node. It also focuses on the effect of shape of the VEHM on its power output. These parameters are actually important as part of the key design parameters in harvesting the vibration from ambient. The energy harvester is made of piezoelectric bimorph bender materials poling in series to transform ambient vibrations into electrical energy. The power output for the VEHM made of single and multiple array of PZT bimorph bender are investigated and the effect of triangular and the rectangular PZT bimorph bender are compared. Two sets of VEHM device have been tested to work in the range of 50 Hz–110 Hz to power up a wireless sensor node for condition monitoring application. The experimental results are presented and compared to the previous similar work. It is found that the triangular shape bender generates more power compared to rectangular form whether it is single or multiple connected in series. Testing results proved that triangular VEHM of the same volume and fundamental frequency when compared to rectangular VEHM can improve the overall power generated by the generator.