The Heterogeneous Packaging of A 3 × 3 Mini-Led Array for Smart Contact Lens Applications

This study focuses on the integration of a 3 × 3 LED array, a driver chip, and an antenna into a HEMA-based contact lens. To ensure biocompatibility and comfortable wearing, the thickness of the contact lens must be less than 200 μm. To achieve this, a flexible substrate was utilized, along with a wireless powering antenna and metal wire for interconnecting the driver chip and Mini-LED array. The system employs 920 MHz RFID technology for the power/data transmission. The chip of the lens can receive 100 μW when the RFID reader’s antenna is 2 cm away, which can drive about 30 μA to the Mini-LED. Real-time control of the Mini-LED display array can be achieved by sending instructions using RFID protocol.