Wireless Power Transfer in Wearable Smart Contact Lenses [Open access]

Yuan, M. and Heidari, H. (2019) Wireless Power Transfer in Wearable Smart Contact Lenses [Open access]. Other. School of Engineering.

Abstract

In 2016, a smart contact lens was developed by Google company which aimed to directly implanting micro-smart lenses into the human eye to test blood sugar percentage by tears. However, small sizes implantable devices such as contact lens requires power transfer unit for continuously power supply. Thus, this project aims to design a power transfer unit with Inductively Coupled Power Transfer (ICPT) technology for smart contact lens which works under 2.45GHz to power an LED at load. The coil size is designed as 10mm inner diameter, 12mm outer diameter and 0.2mm wire width. Additionally, polydimethylsiloxane (PDMS) is used as the contact lens substrate. During the simulation, different eye models were built since the coil needs to be warped on top of lens and the eyeball, and under different conditions the S11 parameter is adjusted to around -10dB. The antenna is fabricated by technician in school, due to the technology restriction, the antenna was fabricated with unequal line width, which causes a resonate frequency shift to 900MHz with -8dB S11 value. To power an LED at load side, full-wave and half-wave rectifiers are built separately with different component values and send to fabrication. The antenna performance was tested under three conditions, in air, on human hand, and on water surface to imitate the liquid condition in human eye, but since the dielectric constant varies in each case, and for fabrication there is an extra circuit unit which effecting the copper coil numbers, the tested resonant frequency is not as desired values.

• Item Type: Research Reports or Papers (Other)
• Additional Information: Submitted for the degree of MSc Electronics and Electrical Engineering. Supervised by Dr Hadi Heidari.
• Status: Published
• Glasgow Author(s) Enlighten ID: Yuan, Miss Mengyao and Heidari, Professor Hadi
• Authors: Yuan, M., and Heidari, H.
• College/School: College of Science and Engineering > School of Engineering; College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Publisher: School of Engineering
• Copyright Holders: Copyright © 2019 The Author
• Publisher Policy: Reproduced with the permission of the Author