A 10mm3 Syringe-Implantable Near-Field Radio System on Glass Substrate.

We present a millimeter-scale near-field radio system for ultra-low-power (ULP) healthcare sensor nodes. It is specifically designed for `syringe implantation' which minimizes invasiveness of implantation. Designing a millimeter-scale wireless node for implanted healthcare is challenging because: 1) the antenna is constrained to the diameter of the syringe needle, which significantly constrains the link distance through RF. 2) The energy/power are strictly limited by the millimeter-scale form-factor where thin-film batteries can source only <;10μAh and sustain <;50μA peak current. Recent works [1-4] have demonstrated near-field transceivers for millimeter-scale implants. Passive backscatter radios consume low power but they are only operable at very short distances (e.g., 3.5cm) due to excessive path loss and self-jamming at the reader [1-2]. Although active radios can provide >10cm distance, their high power consumption (45mW [3]) and/or large antenna size (2.3cm×2.4cm [4]) make them impractical for implanted healthcare applications.