A device for analyzing an analyte in a sample, comprising: a first plate, a second plate, and spacers, wherein: i. the plates are movable relative to each other into different configurations; ii. one or both plates are flexible; iii. each of the plates comprises an inner surface that has a sample contact area for contacting a sample, wherein the sample contains or is suspected to contain an analyte; iv. one or both of the plates comprise the spacers that are fixed on the inner surface of a respective plate, wherein the spacers have a predetermined substantially uniform height that is equal to or less than 200 microns, and a predetermined constant inter-spacer-distance that is in the range of 7 μm to 200 μm; v. the fourth power of the inter-spacer-distance divided by the thickness (h) and the Young's modulus of the flexible plate (ISD 4 /(hE)) is 10 6 μm 3 /GPa or less; and vi. at least one of the spacers is inside the sample contact area; wherein one of the configurations is an open configuration, in which: the two plates are partially or completely separated apart, the spacing between the plates is not regulated by the spacers, and the sample is deposited on one or both of the plates; and wherein another of the configurations is a closed configuration, in which: at least part of the sample is compressed by the two plates into a layer of highly uniform thickness and is substantially stagnant relative to the plates, wherein the uniform thickness of the layer is confined by the inner surfaces of the two plates and is regulated by the plates and the spacers and has an average thickness equal to or less than 5 μm; the device further comprising: a detector that detects the analyte, wherein at the closed configuration the detector detects the analyte in at least part of the sample. a first plate, a second plate, and spacers, wherein: i. the plates are movable relative to each other into different configurations; ii. one or both plates are flexible; iii. each of the plates comprises an inner surface that has a sample contact area for contacting a sample, wherein the sample contains or is suspected to contain an analyte; iv. one or both of the plates comprise the spacers that are fixed on the inner surface of a respective plate, wherein the spacers have a predetermined substantially uniform height that is equal to or less than 200 microns, and a predetermined constant inter-spacer-distance that is in the range of 7 μm to 200 μm; v. the fourth power of the inter-spacer-distance divided by the thickness (h) and the Young's modulus of the flexible plate (ISD 4 /(hE)) is 10 6 μm 3 /GPa or less; and vi. at least one of the spacers is inside the sample contact area; i. the plates are movable relative to each other into different configurations; ii. one or both plates are flexible; iii. each of the plates comprises an inner surface that has a sample contact area for contacting a sample, wherein the sample contains or is suspected to contain an analyte; iv. one or both of the plates comprise the spacers that are fixed on the inner surface of a respective plate, wherein the spacers have a predetermined substantially uniform height that is equal to or less than 200 microns, and a predetermined constant inter-spacer-distance that is in the range of 7 μm to 200 μm; v. the fourth power of the inter-spacer-distance divided by the thickness (h) and the Young's modulus of the flexible plate (ISD 4 /(hE)) is 10 6 μm 3 /GPa or less; and vi. at least one of the spacers is inside the sample contact area; wherein one of the configurations is an open configuration, in which: the two plates are partially or completely separated apart, the spacing between the plates is not regulated by the spacers, and the sample is deposited on one or both of the plates; and wherein another of the configurations is a closed configuration, in which: at least part of the sample is compressed by the two plates into a layer of highly uniform thickness and is substantially stagnant relative to the plates, wherein the uniform thickness of the layer is confined by the inner surfaces of the two plates and is regulated by the plates and the spacers and has an average thickness equal to or less than 5 μm; the device further comprising: a detector that detects the analyte, wherein at the closed configuration the detector detects the analyte in at least part of the sample.