MEMS based energy harvesting for the Internet of Things: a survey

Abstract

The Internet of Things (IoT) can manage a large number of smart wireless devices and form a networking infrastructure connected to the Internet. Traditional batteries in IoT produce environmental concerns and have limited operational life. Harvesting and converting ambient environmental energy is an effective and important approach for sustainable green power used in wireless and portable devices in IoT. This contribution reviews the state-of-the-art development of different energy harvesting sources including mechanical, light/solar, wind, sound, RF, biomechanical and pyroelectric energy. Power density generated from ambient source ranges widely from 0.001 μW/cm2 (RF WiFi) to 100 mW/cm2 (outdoor solar). Depends on application areas and working principles, typical power consumptions of IoT sensor nodes are in the order of mW (1---750 mW) in active mode and μW (0---60 μW) in sleep mode (Mathna et al. in Talanta 75:613---623, 2008; Magno et al. in IEEE Trans Ind Electron 61:1871---1881, 2014; Baranov et al. in Sens Actuators A 233:279---289, 2015; Somov et al. in Procedia Eng 87:520---523, 2014; Spirjakin et al. in Sens Actuators A 247:247---253, 2016; Samson et al. in Sens Actuators A 172:240---244, 2011). Therefore, efficient energy storage and management strategies are important for IoT development. These parts are discussed in order to provide the sustainable power. MEMS based energy harvesting devices may be widely employed in various areas, such as military monitoring, remote weather station, bluetooth headsets, and environment detection. This review focuses on the low power and self powered IoT applications: sensors, wearables, and RF-MEMS. With the advance of nanofabrication techniques, IoT devices will become smaller and enter into the era of Internet of Nano-Things.