An international team of researchers from the Delft University of Technology and Northwestern University has successfully developed a new system that helps battery-less devices memorize time during short power outages. This is a notable finding that will pave the way for mass commercialization of battery-less devices.
Many small, battery-less devices that are part of the Internet of Things (IoT) could operate on the basis of environmental energy — such as solar energy, kinetic energy, and thermal energy. If these devices are introduced on a large scale, fewer batteries will end up in the landfill. However, to date, battery-free devices tend to suffer from short power interruptions when they switch between energy sources.
“Of course, the omission of batteries has consequences,” explained Przemyslaw Pawelczak (TU Delft), one of the main researchers. “It means smaller storage capacity and less reliability. In addition, it is not always possible to predict how much energy can be extracted from the environment.
Josiah Hester (Northwestern University), another of the lead researchers, added: “With that in mind, we’ve now built a system that strings together fragmented active periods. We have built a special system that reliably keeps track of time for IoT devices, even during a large number of power outages.”
Keeping time is an important feature of a computer system, which also helps it maintain and monitor active applications. Most users will only notice that the system keeps track of the time when it fails to happen. Anyone who has had power cuts while using a computer knows how difficult it can be to restart the system. Even if the system starts working again, any unsaved work may be lost.
If this would occur every time a small IoT device — such as a smartwatch, fitness tracker, security camera, smart thermostat or medical sensor — has no power for a while, these devices would be useless.
And that’s what makes the Hester and Pawelczak system so significant. A small device always keeps track of time, even if the power is interrupted for a moment. This allows the system to reboot quickly, so users may not even notice that the power was interrupted.
“Our device can quickly reconstruct time and status from” breadcrumbs “we left before the power went out,” said Hester.
Freedom from batteries
The team’s main goal is to reduce the number of lithium-ion batteries that fill landfills every year. The project will also control the costs and hazards related to lithium extraction. Lithium is a very flammable and toxic substance that may catch fire even in recycling plants.
It’s estimated that in the next 50 years billions of IoT devices will join the tech world. If battery-free devices aren’t encouraged, it may lead to unaccounted discarded batteries.
“It goes without saying that we are developing battery-less systems that extract energy from the environment, given the environmental impact of batteries,” said Pawelczak. “We don’t know exactly how many devices will be added, but no one doubts that the number will be enormous.”
Even other electronics have a larger footprint due to replaceable or rechargeable batteries. This trend needs to change.
“If we want to come up with a vision of sustainable computing, we need to think differently about the design of these systems,” said Hesler.
This newly developed technology will have a huge impact on next-generation devices. It will help in scalable, usable, and more practical IoT devices.