Wireless and Battery-Free Biosensor Based on Parallel Resonators for Monitoring a Wide Range of Biosignals

This paper proposes a novel wireless, battery-free, and label-free biosensor for minimally invasive non-invasive permittivity sensing applications such as detecting glucose levels in the interstitial dermal fluid. The miniaturized, fully passive sensor is based on two symmetric parallel 0.8 mm$^3$ LC (inductor-capacitor) resonators. Each inductor integrated with conductive plate at one of its terminals. sensor's main field dominant outside resonators, creating an effective capacitance sensor, unlike reported previous studies where was limited to between resonator lines. proposed further analyzed under different scenarios change region test suitability pressure monitoring, wound monitoring; first, by repositioning second, replacing resonators plate. experimental results confirmed performance concentration aqueous solution sensitivity 500 46 kHz/(mg/dL) minimal respectively, within range 0-500 mg/dL volume sample requirements low 60 $\mu$L. Further, lies inside making it suitable monitoring. indicated that resonance shift can be made fairly linear respect variation separation 2.5$\times 10^3$ MHz/mm 0.2-0.5 mm, considering factor sense or healing wound.