Efficient communication channel for smart contact lens with resonant magnetoquasistatic coupling

Magnetic resonant coupling is widely used for wireless power transfer in wearables but is typically employed in the strongly coupled regime, where the separation is smaller than or comparable to the device size. This work instead exploits resonant magnetoquasistatic (MQS) coupling to realize a wireless communication link between a necklace-mounted transmitter (Tx) coil and a receiver (Rx) coil embedded in a smart contact lens (SCL). A 15- cm Tx coil and an 8- mm peripheral Rx coil, operating at approximately 26.8 MHz at axial separations of ≈ 15 cm and lateral offsets ≥ 9 cm , form a weakly coupled but robust near-field channel. Finite-element simulations show only ∼ 10 dB path-loss variation across misalignments and a ∼ 5 Mbps channel capacity over 1 MHz bandwidth, sufficient for compressed 480p/15 fps video and multi-sensor telemetry. Because ocular and facial tissues have μ r ≈ 1 below 30 MHz , their presence causes negligible additional attenuation. A benchtop prototype with a 20- cm single-turn Tx coil and 1- cm four-turn Rx coil tuned near 26 MHz shows ∼ 60 dB of channel loss over necklace–eye distances and weak sensitivity to a tissue phantom, supporting the MQS-based analysis. Together, these results establish resonant MQS coupling as a viable high-data-rate communication backbone for future smart contact lenses.