Oxford University’s Tiny Soft Lithium-Ion Battery Activated by Light: Rechargeable and Biodegradable
A research team at Oxford University in the UK has developed a small, flexible lithium-ion battery for biomedical applications, such as powering tiny robots, defibrillators, and pacemakers, as reported by Interesting Engineering on October 25. “To date, this is the smallest hydrogel lithium-ion battery with superior energy density,” said Dr. Yujia Zhang, a lead author of the study from the Department of Chemistry at Oxford University.
Enlarged version of the soft, ultra-small lithium-ion battery. (Photo: Yujia Zhang).
The development of tiny smart devices, often less than 3mm in size, requires correspondingly small power sources. For biomedical devices that interact directly with biological tissues, the power supply must be made from soft materials to ensure safety and minimize invasiveness. Ideally, batteries need to have a high capacity, biocompatibility, biodegradability, and activation capability. They also require remote control capabilities to enhance functionality and adaptability in complex environments. However, integrating all these attributes into a single battery is a significant challenge.
To address this, the team of scientists from Oxford University has developed a small, flexible lithium-ion battery using biocompatible hydrogel droplets. By applying the process of “surfactant-assisted assembly”, the new battery combines three ultra-small droplets, each with a volume of 10 nanoliters, with the support of soap-like molecules. Two of these droplets contain lithium-ion particles that interact to generate energy.
The new battery is light-activated, rechargeable, and biodegradable. In the study, the battery powered charged molecules moving between synthetic cells, as well as controlling heartbeats and defibrillation in mice. By integrating magnetic particles, it can serve as a mobile power source.
According to the research team, animal trials for cardiac treatment demonstrate the potential of the new battery as a promising wireless and biodegradable solution. This innovative design addresses major challenges in powering biomedical devices, providing a biocompatible, safe, and effective solution. The team has already filed a patent application.
