Heterogeneous 3-D ICs as a platform for hybrid energy harvesting in IoT systems

Three-dimensional integrated circuits are a natural platform for IoT systems. IoT systems exhibit a small footprint, integrate disparate technologies, and require long term sustainability (extremely low power or self-powered). A hybrid energy harvesting system within a three-dimensional integrated circuit is proposed in this paper. The harvesting system exploits different types of energy available from the ambient (electromagnetic, solar, thermal, and kinetic). Integration of the hybrid harvesting system onto a three-dimensional platform ensures that each type of harvested energy can be individually collected. Both static and dynamic evaluations of a hybrid energy harvesting system are provided. For an example IoT system, the static power requirements are approximately 85% of the power delivered to the load. In the dynamic evaluation, a range of activity factors characterizing the load and different storage capacitors are considered. The power requirements of a typical IoT system are shown to be satisfied by a hybrid energy harvesting system within a 3-D platform.