Energy Harvesting Device

About

Low-power microcontrollers have laid the foundation for the vast expansion of portable electronics. Pushing this edge further is the promising study of ambient energy harvesting for powering such devices. The practicality of current methods, however, are limited by fixed rates of energy extraction, the types of energies that can be harnessed, and the level of required dedicated storage circuitry. In combination with the low-level power inherent to ambient sources, how these technologies can be successfully integrated into everyday devices remains a key challenge. Researchers at the University of Hawaii have developed an efficient system for harvesting ambient energy by circuit reconfiguration. This method is composed of a network of charge storage devices that differ in capacitance. Through dynamic switching between configurations, stored energy grows exponentially with each cycle allowing its generative capacity to be scaled up according to application. The energy harvested from potential low-level source (e.g., human motion, vibrational) can effectively be stored directly in the system without the need for external batteries; however, system operation in tandem with batteries is not precluded. Additionally, an external voltage bias is not required for this method’s operation.