Ultra-thin tag fabrication and sensing technique using third harmonic for implantable wireless sensors

This paper presents the fabrication of an ultra-thin tag for identification and sensing applications in extremely small implantable regions. Particularly, we are demonstrating the capability to create a telemetry system which is implantable in a mouse eye. This system will eventually be able to monitor intraocular pressure (IOP). The small size of the mouse eye presents challenges for surgery and the integration of components. Therefore, there is a need for a device which is biocompatible, flexible, compressible, self-expandable, and thin enough for implantation. This paper demonstrates the fabrication of a thin tag with a self-expandable Nitinol antenna, polymer based embedded components, and high density routing. Telemetry with a small tag implanted inside of the eye is established for the first time using the 3^rd order harmonic response from the implanted device.