Ultra-low-power circuit techniques for mm-size wireless sensor nodes with energy harvesting

Abstract

This paper describes circuit techniques for energy-harvesting technology in millimeter-size ultra-low-power batteryless wireless sensor nodes as a front end for BigData, IoT, M2M, and ambient intelligence. Power generated by energy harvester becomes as small as the nanowatt level when the size of a sensor node becomes millimeter-size. First, technical trends in low-power circuits and the portfolio of energy harvesting and circuit technology are discussed from the viewpoints of technical and application issues. Then, circuit techniques for nanowatt level wireless sensor nodes—a zero-power vibration sensing circuit, power management with MEMS switch, and an intermitted RF transmitter—are explained.