Low-Cost Polymeric Energy Harvester as Vibration Intensity Sensor

We report on the design, fabrication, and experimental functionality demonstration of a simple, manufacturable, and cost-effective polymeric vibration intensity monitoring sensor for industrial applications. In the device combining sensing, energy harvesting, data processing, edge computing, and wireless connectivity functionalities, the electromagnetic harvester's output is used for the vibration intensity sensing. The electromechanical core of the device is realized as an assembly of three free-standing polyethylene terephthalate (PET) membranes with an array of micro magnets attached to them. The vibration of the magnets in proximity to the micro coils induces an electric current in the circuit and enables the EEPROM bit writing operation. The number of the ON/OFF voltage switching and memory writing events in unit time, each corresponding to the stored energy threshold level crossing, is used as a condition monitoring indicator. The output voltage of 1.2 Vpp (peak to peak) was measured in the 3 mm thick and 30 mm in diameter harvester operated at the accelerations of ≈31 g and frequencies between 860 and 930 Hz. The feasibility of the sensor operational cycle, including energy harvesting and storage, memory writing, and wireless data reading, was demonstrated.