Fig. 4: Spectrometric measurement of various solid and liquid samples.
a, Photos of some representative solid and solution samples under test (left) and diagrams illustrating the experimental setups for solid reflectance and liquid transmittance measurements (right). b, Measured reflectance spectra of different plastic samples (80 repetitions per sample), with references measured using a benchtop spectrometer. c, Measured reflectance spectra of different pharmaceuticals, coffee, flour and tea, respectively. d, Confusion matrix of the classification results, using plastic samples as an example. e, Measured absorptance spectra of aqueous solutions (ethanol, lactate, glucose) and organic solutions (ethylene glycol in isopropanol) across concentrations from 0.1% to 40% (80 repetitions per concentration). f, The predicted concentrations via the SVR model versus the actual concentrations, using glucose solution measurements as an example. g, Schematic of a dynamic solution-mixing system with two solutions of different concentrations being injected. h, Real-time tracking of glucose solution concentration using a pretrained SVR model, achieving a system-level time resolution of 4.9 s. Solid and dashed arrows denote the injection of high- and low-concentration solutions, respectively. i, Comparison of concentration prediction accuracy between our device and commercial benchtop spectrometers in glucose solution tests, using their partial and full working bandwidths for data acquisition, respectively.
