Encoding of blink information via wireless contact lens for eye-machine interaction

Blinks controlled by ocular muscles and nerves can manifest as either involuntary physiological behaviors or volitional control actions, with the former serving spontaneous protective functions while the latter constitutes a biologically meaningful communicative signal. The encoding of blink information provides a novel eye-machine interaction (EMI) prototype within the realm of human-machine interaction, expanding human consciousness-capability boundaries. It facilitates motor and language rehabilitation, silence communication, and even voluntary command execution. However, existing EMI devices face challenges related to wireless functionalities, ocular comfort, and multi-route encoding-decoding orders. Here, we propose a wireless eye-wearable lens to encode conscious blink information via introduction of an RLC oscillating loop in the soft contact lens. The developed EMI contact lens incorporates a mechanosensitive capacitor, an inductive coil and the inherent loop resistance, generating characteristic resonance frequency for front-end capacitance signal transition or back-end control signal extraction. The EMI device delivers a sensitivity of 0.153 MHz/mmHg in the wide range of 0-70 mmHg for normal IOP monitor and realizes consciousness-blink-based control command coding. Trial with participants inserted with the EMI contact lens demonstrates its wearability and biocompatibility. Finally, the 5-route blink-based control command decoding mechanism is constructed via EMI lens, linking blink counts to a drone's flight trajectory. The EMI contact lens offers innovative prototypes that transcend the capabilities of traditional brain-computer interfaces.