Towards the Monolithic Integration of Converter Circuitry and Piezoelectric MEMS Energy Harvesters

Abstract

One of the main difficulties for a global implantation of the Internet of Things (IoT) is the energy dependence of the nodes, limited by the battery’s lifetime. Energy harvesting seems to be a promising solution to provide energy autonomy to IoT nodes. Power management circuits are needed to collect and store the charges scavenged form the ambient sources. In addition, this circuit needs to adapt the output voltage to power the wireless sensor node. Because of the typical heterogeneity of the system, the cost and difficulties associated to the encapsulation of the CMOS chip and the energy harvester can be important. They could be reduced by using a monolithic integration of both parts in a single chip or package. In this work, we propose a fully monolithically integrated system comprised by a power management circuit, a piezoelectric microgenerator and a storage capacitor. With this solution, which combines MEMS and CMOS technologies, we pave the way to the future development of autonomous smart dust.

Keywords

• IoT
• MEMS
• energy harvesting
• monolithic integration
• piezoelectric
• CMOS
• charge pump
• self-powered
• AlN