Efficient Communication and Powering for Smart Contact Lens with Resonant Magneto-Quasistatic Coupling

TL;DR

This paper demonstrates a novel wireless communication and power transfer system for smart contact lenses using resonant magneto-quasistatic coupling with a necklace transmitter, enabling robust AR/VR and health monitoring applications.

Contribution

It introduces a two-coil system utilizing resonant MQS coupling for contact lenses, achieving efficient, misalignment-tolerant wireless communication and power transfer at practical distances.

Findings

Maximum path loss variation within 10 dB across misalignments

Communication channel capacity of 4.5 Mbps over 1 MHz bandwidth

Negligible path loss difference with or without human tissues

Abstract

A two-coil wearable system is proposed for wireless communication and powering between a transmitter coil in a necklace and a receiver coil in a smart contact lens, where the necklace is invisible in contrast to coils embedded in wearables like spectacles or headbands. Magneto-quasistatic(MQS) field coupling facilitates communication between the transmitter in the necklace and the contact lens receiver, enabling AR/VR and health monitoring. As long as the receiver coil remains within the magnetic field generated by the transmitter, continuous communication is sustained through MQS field coupling despite the misalignments present. Resonant frequency tuning enhances system efficiency. The system's performance was tested for coil misalignments, showing a maximum path loss variation within $10 dB$ across scenarios, indicating robustness. Finite Element Method(FEM) analysis has been used to study the system for efficient wireless data transfer and powering. A communication channel capacity is $4.5 Mbps$ over a $1 MHz$ bandwidth. Simulations show negligible path loss differences with or without human tissues, as magnetic coupling remains unaffected at MQS frequencies below $30 MHz$ due to similar magnetic permeability of tissues and air. Therefore, the possibility of efficient communication and powering of smart contact lenses through a necklace is shown for the first time using resonant MQS coupling at an axial distance of $15cm$ and lateral distance of over $9cm$ to enable AR/VR and health monitoring on the contact lens.