A WIRELESSLY POWERED RFID-BASED SMART CONTACT LENS SYSTEM

摘要

This paper presents a wireless smart contact lens system, comprising a capacitive sensor interface circuitry and a wirelessly powered radio frequency identification (RFID)-compatible system, for sensor control and data communication. To improve compliance and reduce user discomfort, the capacitive sensor was embedded on a 200-μm-thick soft contact lens using commercially available biocompatible lens material and a standard sandwich manufacturing process. The proposed lens can communicate with RFID equipment at an ultra-high frequency (UHF) RFID frequency of 920 MHz. A successful communication distance of 2 cm was achieved under 18 dBm incident radio frequency (RF) power, and a maximum distance of 4 cm was achieved under 28 dBm incident power. The uniform magnetic field distribution of the transmitting antenna enhances energy transmission and provides robust operation against shifts in relative location and misalignment of the contact lens and the glass caused by eye movement and blinking.