Ultracompact SLSP sensor for rapid detection of grain moisture

In this work, we propose a methodology for grain moisture content detection based on a spoof localized surface plasmons (SLSPs) resonator, enabling highly efficient and precise quantification of moisture levels in grains. We conducted tests within the 0.9-1.1 GHz frequency range on nine wheat samples with varying moisture contents, successfully obtaining corresponding transmission spectra. Through calculation and in-depth analysis, a linear regression equation for wheat moisture content was established, with a coefficient of determination (R²) as high as 0.985. Experimental data indicated that the root mean square error (RMSE), mean absolute error (MAE), and maximum relative error (MRE) of predicted values were 0.321%, 0.24%, and 7.6%, respectively.