| CPC G01N 29/022 (2013.01) [G01N 29/2418 (2013.01); G01N 2291/014 (2013.01)] | 20 Claims |
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1. A quartz crystal microbalance, comprising a resonant module, an optical imaging module and a data processing module, wherein
the resonant module comprises an assembly model and a resonant voltage source;
the assembly model comprises a quartz crystal microbalance chip, wherein a surface of the quartz crystal microbalance chip carries a sample to be tested, and the resonant voltage source is configured to drive the quartz crystal microbalance chip;
the optical imaging module comprises a microscope and an image acquisition device;
the assembly model is fixed on an objective stage of the microscope, wherein the microscope is configured to magnify the sample to be tested; and the image acquisition device is configured to perform optical imaging on the sample to be tested magnified by the microscope to acquire an image, and to send the image to the data processing module;
the data processing module is configured to analyze and process the image to determine an optical resonant frequency of the sample to be tested; and determine mass of the sample to be tested according to the optical resonant frequency;
wherein the data processing module is configured to, when the image acquisition device is a charge-coupled element, perform the following processing on images scanned at a plurality of frequencies sent by the charge-coupled element: determining a full width at half maximum (FWHM) of a light spot in the image in a first direction and an FWHM of the light spot in the image in a second direction; comparing the FWHM of the light spot in the first direction with the FWHM of the light spot in the second direction to obtain a comparison result, and taking a ratio of a larger value to a smaller value in the comparison result as an ellipticity; determining a first relationship curve between the ellipticity and the frequency according to the plurality of frequencies and the corresponding ellipticities; and taking a frequency corresponding to a maximum ellipticity in the first relationship curve as the optical resonant frequency of the sample to be tested, wherein the first direction is perpendicular to the second direction; or
the data processing module is configured to, when the image acquisition device is the charge-coupled element, fit the images scanned at the plurality of frequencies sent by the charge-coupled element to obtain a fitted image for each of the plurality of frequencies, determine a motion path range of a light spot in the fitted image by a deconvolution algorithm, determine a second relationship curve between the motion path range of the light spot in the fitted image and the frequency according to the plurality of frequencies and the corresponding motion path ranges of the light spot in the fitted image, and take a frequency corresponding to a maximum of the motion path range in the second relationship curve as the optical resonant frequency of the sample to be tested; or
the data processing module is configured to, when the image acquisition device is a phase-locked complementary metal oxide semiconductor device, determine optical intensities of images scanned at the plurality of frequencies sent by the phase-locked complementary metal oxide semiconductor device, determine a third relationship curve between the optical intensity of the image and the frequency according to the plurality of frequencies and the corresponding optical intensities of the images, and take a frequency corresponding to a maximum optical intensity in the third relationship curve as the optical resonant frequency of the sample to be tested.
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