High throughput and label-free particle sensor based on microwave resonators

Abstract We developed a novel particle sensor based on micro channels embedded in microwave resonators, which are fabricated by standard print circuit board manufacturing technology. The sensing frequency falls in the range 2–4 GHz, the widely used microwave S band. A 70 μm-particle can produce a frequency shift of 0.5 MHz in a sensor with 150 μm channel size, with a dwell time of 0.5 ms by using double split ring resonators. These resonator sensors may employ phase-locked loop in achieving a higher detection resolution.