Management and storage of energy converted via a pyroelectric heat engine

Heat is a ubiquitous energy resource, which is easily accessible from the environment. The pyroelectric effect, a phenomenon that converts temperature variation into electricity, enables a material to be operated like a heat engine between high and low temperatures and electric fields, producing electrical work. However, current literature focuses on material performances, with no energy stored by operating in such conversion cycles. This work presents a complete pyroelectric management system that both realized cycled energy conversion and a maximum harvested power up to 13.1 μW. We achieved this by integrating a laser heat source, an advanced pyroelectric device, a practical power interface, and an energy storage component together. A thin film Lead Zirconate Titanate device was fabricated to achieve very fast temperature response (∼0.1 ms). Thus, the energy conversion can be achieved in a much higher thermodynamic frequency (1 kHz), leading to a larger power density. The proposed power interface manages an optimized pyroelectric conversion cycle while recharging a battery, or a storage capacitor (up to 2.1 V). The results provide a promising method to harvest energy from waste-heat and have shown great potential to supply power to small-scale, distributed devices. In addition, the application of the laser source has also enabled the system to achieve wireless power transmission, which would enable a more flexible way to supply power to multiple devices.