University of Waterloo researchers have developed a fully battery-free, hydro-powered sensor that can transmit alerts over long distances and potentially connect directly to satellite uplink without any local gateways or battery power. The breakthrough could significantly expand the reach and sustainability of Internet of Things (IoT) technologies, particularly in remote or infrastructure-poor environments.
Led by Dr. George Shaker, Professor in the Department of Electrical and Computer Engineering, and Dr. Norman Zhou, Professor in the Department of Mechanical and Mechatronics Engineering, the research demonstrates how ultra-low power sensors can use existing 5G and emerging satellite-enabled networks to send critical information only when activated by their environment. The work is conducted together with student researchers and supported by Rogers Inc., Natural Sciences and Engineering Research Council of Canada, and MITACS.
The study highlights Waterloo's role as a hub where academic research and industry collaboration converge to address real-world challenges and demonstrates the University's ability to design technologies ready for deployment at scale.
Improved leak detection
"The legacy approach to sensors relies on local gateways and batteries, limiting scalability, adding environmental burden and increasing maintenance overhead," Shaker says. "The proposed battery-free system eliminates the need for local infrastructure by connecting directly to cell towers, creating a feasibility path toward future satellite connection which in turn unlocks a wide array of diverse applications."
The study outlines a commercially viable use case for the battery-free, hydro-powered sensor: detecting hidden structural water leaks. The sensor harvests energy directly from the leak itself. When water touches the sensor, a small electrochemical reaction generates enough electricity to power the wireless radio on, sending a leak alert over the 5G network. This approach is particularly useful in the detection of infrastructure issues like pinhole leaks behind drywall or failing HVAC condensate lines, which frequently remain undetected for weeks or months and can lead to mold or drywall damage.
The battery-free model offers additional benefits. "By using environmentally friendly material, the aging problems of batteries can be avoided," Shaker says. "And as the system is modular, only the low-cost sensor needs to be replaced once a leak is discovered."
It takes about 20 minutes of continuous moisture for the device to charge enough to send its first message. This delay is beneficial because it filters out false alarms from things like spills, cleaning or condensation. This represents a significant improvement over manual inspection cycles, providing timely intervention capability without the logistical burden of battery maintenance.
The Rogers 5G network advantage
The work is part of an ongoing Rogers partnership, which is key to this research as the company is both Canada's largest 5G carrier and a leader in integrating terrestrial and satellite-enabled connectivity to extend coverage beyond traditional network boundaries. This gives the Waterloo team access to a network where a single device, with a single radio, can reach either a nearby cell tower or a low Earth orbit satellite, whichever happens to be in range.
"The same sensor that reports a leak in a downtown condo can report one from a cottage on a remote lake, where there has never been cellphone coverage and likely never will be," Shaker says. "There is no second product to design and no second radio to build. The connection follows the device."
The sensor produces only a small amount of power when water reaches it, and that shapes which networks it can use. Newer 5G standards such as NB-IoT and LTE-M, along with the satellite extensions now being added to them, were built for devices that wake up briefly, send a short message, and go quiet again just like the novel sensor.
The team sees the impact extending well beyond water leaks, including innovative dual-use applications. In defence settings, the absence of a battery is a significant advantage, since batteries give off heat and chemical traces that can be detected by thermal cameras. A sensor that draws power only when activated by its surroundings, leaving nothing to detect when idle.
Data centres are another good fit. Lithium-ion batteries are increasingly seen as a fire risk in the rooms they are meant to protect. For example, a moisture sensor that contains no battery and cannot burn is a smart alternative. "Water is one of the biggest threats to a data centre," Shaker says, "Our sensor stays dormant until the moment it is needed and then sends the alert that operators most need to hear."
For Waterloo researchers, access to the Rogers 5G and extended-coverage connectivity environment is valuable because it allows a coin-sized sensor, powered by a drop of water, to use the same connection as a cellphone anywhere in the country.
