MICROFLUIDIC ABSORPTION CELL

摘要

An absorption cell for microfluidic chemical analysis made from tinted or coloured polymers, for example polymethylmethacrylate (PMMA), in which microfluidic channels are cut. Light is coupled into the absorption cell via two windows (typically 200 um thick) that are retained at either end of the channel. Absorption is measured using a light source, such as a light emitting diode (LED) and a photodiode butted against the windows. Spurious scattered and/or reflected light is absorbed by the coloured polymer over the length of the measurement cell, while very little light loss occurs at the coupling windows.

主权项

1. An absorption cell for measuring absorption of a fluid analyte at a sensing wavelength, or range of sensing wavelengths, by exposing the analyte to probe light of the sensing wavelength or sensing wavelength range, the absorption cell comprising:
a microfluidic sensing channel having first and second ends so as to provide a fluid path for the analyte as well as an optical path for the probe light; first and second windows adjacent the first and second ends of the sensing channel which are transmissive to the probe light;wherein
the sensing channel is formed in a tinted material which is neither transparent nor opaque to the probe light, but rather transmissive and absorbent to the probe light, and in that the first and second windows are formed in the tinted material integrally with the sensing channel.