Monitoring Eye States Based on Transparent and Flexible Antenna in WBAN

With the development of wireless body area network (WBAN), the integration of transparent and flexible antennas into wearable devices has been widely studied. Transparent and flexible antennas can be compatible with devices of different shapes, sizes and materials, achieving device miniaturization. Wearable antennas can achieve lightweight, flexible, low-cost, and portable wireless communication and sensing. This letter aims to design and fabricate a transparent and flexible monopole antenna operating at 5.8 GHz, fed by coplanar waveguide (CPW). We selected 650-nm-thick indium tin oxide (ITO) as conductor and 0.125-mm-thick polyethylene terephthalate (PET) as substrate. The surface resistance of the antenna is 2-3 (Ω/sq), the average transparency is 73%, and the gain at 5.8 GHz is 1.074 dBi. We integrate this antenna into the lens for eye states monitoring and use vector network analyzer to measure return loss in three states: closing, opening, and blinking. And after data processing, the blinking frequency can be accurately estimated.