High precision glucose concentration detection based on near-field focused metasurface

A near-field focused metasurface is proposed for high-precision detection of glucose concentration. The position of the near-field focus has a high sensitivity to the dielectric constant of glucose, which can greatly improve the detection accuracy of glucose concentration. The size of the metasurface is 400×400×1mm
³
, which is composed of 20×20 heterogeneous elements. The measured results show that the glucose testing is sensitive to the minimum permittivity change (≥0.027%) of glucose, and the detection error is less than 3.71%, which shows good agreement with the simulation results.