Smart Contact Lenses Get Tear-Powered Batteries

Researchers in Singapore have developed an ultra-thin battery for smart contact lenses that charges on tears.

Ntu Singapore
NTU Singapore

According to a recent Interesting Engineering article, researchers at Nanyang Technological University (NTU) in Singapore have developed a revolutionary micrometer-thin battery designed for smart contact lenses. Unlike existing methods that use wires and toxic metals for power, this innovative battery can be charged using human tears. The NTU research team created the battery from biocompatible materials with a glucose-based coating. The coating reacts with sodium and chloride ions in the water inside the battery, generating electricity and effectively charging the battery as the wearer uses the lenses. The battery’s capacity is sufficient to power the device for most of the day. Even better, immersing the battery in a simulated tear solution or concentrated saline solution enhances its lifespan, extending its usage time.

The innovation holds promise for advancing the field of smart contact lenses. Current versions often rely on thin batteries with wires and induction coils, posing potential risks to eye health. The NTU team's battery not only eliminates these risks but also overcomes space limitations by combining the battery and biofuel cell into a single component. The research team aims to further enhance the battery's electric current output and is partnering with contact lens manufacturers to bring this groundbreaking technology to market.