Researchers at Nanyang Technological University in Singapore have developed a super-thin, flexible battery designed for smart contact lenses. This innovative battery, as thin as the human cornea, can be charged using a saline solution, making it suitable for use in the eye, which is naturally bathed in salty tears. When the smart lens is not in use, it can be stored in a saline solution to recharge the battery further. Unlike conventional batteries, this device avoids materials that could harm the eye, such as metal electrodes. Instead, it relies on a glucose oxidase coating to generate electricity when it reacts with ions in tears, like sodium and potassium.
Smart contact lenses that can monitor health and treat diseases are on the horizon, but they require a reliable and safe power source. The challenge lies in creating thin lenses that won’t damage the eye’s surface if exposed. Traditional bulky batteries are not suitable. To tackle this, the researchers have developed a thin battery without metal electrodes that can harness power from the eye itself, specifically from the salty tears.
Yun Jeonghun, one of the lead developers, highlighted the limitations of other battery charging methods, such as metal electrodes or induction charging, and explained how their tear-based battery eliminates these concerns, allowing for further innovation in smart contact lens development.
The researchers have tested the battery using a simulated human eye and achieved promising results, with the device producing current and power, as well as demonstrating the potential for multiple charge/discharge cycles. Lee Seok Woo, another researcher, explained that their approach relies on a combination of enzymatic and self-reduction reactions to charge both electrodes and uses only glucose and water to generate electricity, ensuring safety for humans and less environmental harm during disposal compared to conventional batteries.
Article written by CoNN Hastings| Image by Pixabay