An indoor air duct flow energy conversion system for powering Wireless Sensors

In this paper, an indoor low-speed airflow energy harvesting system based on aerodynamic flutter is proposed to power up Wireless Sensor Networks (WSNs). Steady mechanical vibration always can be observed due to the aerodynamic forces while airflows pass through flexible belt-like structure. Oscillating electromagnetic resonator has been designed to covert mechanical power into electricity according Faraday´s law. Optimizations for both belt-flutter subsystem and electromagnetic resonator are carried out to maximize the conversion efficiency. The airflows from a 0.5m×0.5m square air conduct diffuser are used to stimulate the energy conversion system in experiments, which is widely installed in business office, warehouse and parking, etc. A prototype of flutter energy conversion device for indoor air conduct is demonstrated to power up a commercial wireless sensor. With the power management and super capacitors as buffer, those wireless nodes could transmit for several minutes periodically after charging under ~2 m/s speed airflow.