Self-powered wireless sensor balls for homeland security

In this paper, the development of affordable self-powered wireless sensor balls is proposed for environmental monitoring. Depending on the area of interest, multiple balls can be either thrown or rolled from a distance into the surrounding area of interest or placed beside the object of interest, and send sensory information back to a central base station, i.e., a laptop, for sensor fusion and processing. In order to achieve fast and robust deployment, reliable data delivery, and smart power management, the paper focuses on the potential wireless network and energy harvesting scheme of the balls. In particular, to support a large number of sensor balls, we show that shortest path routing is essential in minimizing network latency and guarantee timely delivery of critical and emergency information. Furthermore, a vibration-based electromagnetic energy harvesting technique is investigated to capture the energy from the motion of the balls. Experimental results demonstrate the potential development of a network of autonomous self-powered wireless sensor balls.