Maximize piezoelectric energy harvesting using synchronous charge extraction technique for powering autonomous wireless transmitter

Interest for harvesting energy from the environment to sustain the operational lifetime of any battery-driven electronic device like wireless sensor nodes has been growing tremendously. One prominent challenge with energy harvesting sources is the deficiency in energy supply to continuously power the electronic devices even with the rapid advancement in ultra low power microelectronic technology. To overcome that, the synchronous electric charge extraction technique has been used to maximize the energy harvested from vibrational energy source using the piezoelectric generator. A low power synchronized switch control circuitry, which consumes 300 muW @ 5 V supply, has been designed and implemented to achieve synchronous charge extraction from the piezoelectric generator. Experimental results have verified that using the synchronous charge extraction technique as compared to the standard rectifying circuit, more electrical energy can be harvested from the piezoelectric generator with an increase from 1.75 mW to 5.6 mW. The harvested electrical energy is used to power the 433 MHz wireless transmitter to transmit 12-bit digital data to the remote base station.