Researchers at the University of Oxford have made a significant breakthrough in creating tiny, soft batteries designed for medical devices and small robots.
These new batteries could revolutionize the way we power tiny biomedical devices, especially those used inside the human body.
Their work has been published in the journal Nature Chemical Engineering.
As technology advances, there’s a growing need for small, smart devices that can work in or near biological tissues.
However, powering these tiny devices is challenging. Ideally, their batteries should be not only small but also soft, biocompatible, biodegradable, and capable of being remotely controlled. No existing battery could meet all these requirements—until now.
Researchers from Oxford’s Department of Chemistry and Department of Pharmacology have developed a miniature, soft lithium-ion battery. This battery is made from tiny droplets of hydrogel—a soft, water-based material that is safe for biological tissues.
The team used a special technique called surfactant-supported assembly to build the battery. This method, reported by the same group last year, connects three tiny droplets of hydrogel.
These droplets are incredibly small, with each one holding only about 10 nanoliters (one nanoliter is one-billionth of a liter). By using lithium-ion particles in two of the droplets, the battery generates energy.
What makes this battery stand out is that it’s light-activated, rechargeable, and can break down safely after use.
According to Dr. Yujia Zhang, who led the study and is now an Assistant Professor at École Polytechnique Fédérale de Lausanne, the battery is the smallest of its kind and has a high energy density compared to similar batteries.
The battery’s unique design allows it to power a range of biomedical applications. For example, the team used it to release charged drug molecules between synthetic cells and to control the heartbeat of mouse hearts in lab tests. They even demonstrated that the battery could help defibrillate heart tissues—a technique used to correct irregular heartbeats.
Professor Ming Lei, an expert in heart conditions and part of the research team, highlighted the battery’s potential in treating cardiac arrhythmias, which are irregular heartbeats that cause many deaths worldwide. He emphasized that this tiny battery could pave the way for new wireless and biodegradable devices for heart treatments.
Professor Hagan Bayley, the research group leader, praised Dr. Zhang’s achievement, saying that this tiny, soft lithium-ion battery is the most advanced in their series of small power sources. The battery’s ability to work in natural conditions, while being safe for the body, points to a bright future for biocompatible electronics.
The team has already filed a patent for their invention through Oxford University Innovation. They believe that this new type of battery could open up exciting possibilities in clinical medicine and small-scale robotics.
By enabling devices that can be safely used in or near the human body, this tiny battery could lead to significant advancements in healthcare and beyond.
Source: University of Oxford.
