For decades, the limitations of batteries have restricted the monitoring of critical infrastructure, but a breakthrough by MIT researchers may change that. The newly unveiled ‘HoloTile’ floor is a significant step closer to enabling sensors embedded within a ship’s engine to provide real-time data without the need for cumbersome wires or battery replacements.

MIT researchers, led by Disney Research fellow Lanny Smoot, have developed a sensor that harvests energy from its surroundings, eliminating the need for batteries or wired connections. This groundbreaking sensor can be applied in challenging environments, such as inside a ship’s engine, to monitor machine performance and efficiency seamlessly.

The sensor, designed to clip around a wire carrying electricity, captures magnetic field energy generated by the wire’s current. This energy is then utilized to measure the temperature of the motor. Steve Leeb, the senior author of the paper and a professor at MIT, describes it as “ambient power,” emphasizing its easy installation without specific soldered connections.

Published in the January issue of the IEEE Sensors Journal, the paper details the design principles and challenges of creating a battery-free, self-powered sensor. The researchers offer a design guide, covering key components like the energy harvester, energy storage, power management, sensing circuit, and communication module, enabling engineers to balance environmental energy with the device’s sensing needs.

The sensor continuously senses and controls energy flow during operation, storing excess energy for later use. It can even cold start, booting up its electronics with no initial voltage using integrated circuits and transistors. This design framework is versatile, applicable not only to sensors using magnetic field energy but also to those using vibrations or sunlight.

Daniel Monagle, the lead author of the paper and a graduate student at MIT, envisions the framework enabling the development of cost-effective sensor networks for applications in factories, warehouses, and commercial spaces.

The battery-free, energy-harvesting sensor holds potential implications for ship systems monitoring, as noted by John Donnal, an associate professor at the U.S. Naval Academy. Donnal suggests that energy-harvesting systems could facilitate the retrofitting of diagnostic sensors on ships, reducing overall maintenance costs significantly.

The researchers avoided using a battery to simplify the sensor and mitigate safety risks. Instead, they incorporated internal energy storage, including capacitors, designed to balance charge-up time and energy storage needs. The control algorithms dynamically measure and budget energy, ensuring the sensor operates maintenance-free, harvesting energy and operating autonomously.

Looking ahead, the researchers plan to explore less energy-intensive means of data transmission, such as optics or acoustics, and further model and predict energy needs for enhanced data gathering. The goal is to develop a comprehensive framework that allows a device to effectively gather more data, offering valuable insights into operations.

By Impact Lab