Power supply for a smart contact lens 1

• Main Author: Lei, Hang
• Other Authors: Lee Seok Woo
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/176698
• Institution: Nanyang Technological University

In recent years, smart contact lenses have gained significant traction, emerging as a promising technology. However, one of the primary challenges hindering their development lies in the power supply system. The availability of a safe, reliable, and biocompatible battery is crucial for the advancement of smart contact lenses. To tackle this issue, the concept of tear-based batteries has been introduced. Tear-based batteries utilize the composition of human tears to provide a natural and sustainable power source for smart contact lenses. Prussian blue (PB) and its analogs, known as Prussian Blue Analogues (PBA), have been leveraged to fabricate flexible nanoparticle-shaped electrodes, serving as both cathodes and anodes. These electrodes operate with sodium ions (Na+) and potassium ions (K+), which are abundant in human tears. The contact lens covers are formed using polymerized hydrogel, ensuring compatibility with the eye. For the electrochemical assessment of the tear-based battery, artificial tears resembling the composition of human tears were utilized. These artificial tears comprised a solution containing 0.2 mol of NaCl and 0.02 mol of KCl, enabling the simulation of the tear environment. Electrochemical evaluation was conducted using cyclic voltammetry (CV) and galvanostatic cycling (GCPL) techniques, providing insights into the performance and behavior of the tear-based battery under various conditions. In summary, the tear-based battery represents a promising solution to the power supply challenges faced by smart contact lenses. By harnessing the natural components of human tears and employing innovative electrode materials, this approach holds the potential to advance the development of smart contact lenses towards greater safety, reliability, and functionality.