Eyeglasses-powered, contact lens-like platform with high power transfer efficiency

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Ophthalmology

Background:

• Wireless power transfer is crucial for miniaturized implantable devices.
• Smart contact lenses offer potential for continuous ocular monitoring.
• Existing power solutions for contact lenses face challenges in efficiency and form factor.

Purpose of the Study:

• To develop a wirelessly powered contact lens platform.
• To investigate efficient power transfer mechanisms for contact lenses.
• To demonstrate the feasibility of a smart contact lens for ocular diagnostics.

Main Methods:

• A contact lens platform was fabricated using a transparent parylene film and an embedded spiral inductor.
• A multilayer thin-film parylene packaging process was employed for the contact lens form factor.
• A 36 μm-thick metal plating technique enhanced the receiving coil's quality factor (Q=27.3 at 13.56 MHz).
• Wireless power transfer was demonstrated using magnetic resonance coupling via eyeglasses, with misalignment compensation techniques.

Main Results:

• The contact lens platform achieved a power transfer efficiency of 17.5% at a 20-mm distance on a pig eye model.
• The effect of biological tissue on coil performance and power transfer was analyzed.
• The enhanced quality factor of the receiving coil contributed to efficient power reception.

Conclusions:

• The developed wirelessly powered contact lens platform demonstrates significant progress towards functional smart contact lenses.
• The high power transfer efficiency and wearable prototype show promise for future ocular diagnostic applications.
• This technology could enable new non-invasive methods for monitoring eye health.