SINGAPORE: Scientists from Nanyang Technological University (NTU) have achieved a groundbreaking feat with the development of a flexible battery as thin as a human cornea. This revolutionary battery has the capacity to store electricity when submerged in a saline solution, opening doors to the possibility of powering smart contact lenses in the future.
Led by Associate Professor Lee Seok Woon from NTU’s School of Electrical and Electronic Engineering (EEE), the research team’s breakthrough holds the potential to reshape the realm of wearable technology.
Smart contact lenses, which have been gaining momentum in recent years, can display visible information directly on the corneas of users, offering applications in augmented reality, vision correction, health monitoring, and disease detection for individuals with chronic conditions such as diabetes and glaucoma.
The current limitation for smart contact lenses has been the lack of a suitable and safe power source. Traditional rechargeable batteries employ wires or induction coils containing metals, which are neither comfortable nor safe for use in the human eye.
Addressing this challenge, NTU’s battery innovation is crafted from biocompatible materials, eliminating the use of toxic heavy metals that are commonly found in lithium-ion batteries and wireless charging systems.
The cutting-edge battery features a glucose-based coating that interacts with the sodium and chloride ions present in the surrounding saline solution. Notably, the water within the battery itself functions as a ‘wire’ or ‘circuitry,’ facilitating the generation of electricity.
Moreover, the innovative design allows the battery to be potentially powered by human tears, which naturally contain sodium and potassium ions at a lower concentration.
In a simulated tear solution test, researchers demonstrated that the battery’s lifespan could be extended by an additional hour for every twelve-hour wearing cycle, highlighting the potential longevity of the battery when powered by tears.
The battery also retains the option of conventional charging through an external power supply, offering greater flexibility to users.
This advancement from NTU’s researchers could pave the way for a future where smart contact lenses can record and transmit a wearer’s visual and auditory experiences to cloud-based data storage.