The properties, preparation approaches and uses of microfluidic channels for terahertz absorption signatures detection in aqueous

A microfluidic channels chip and its processing method and application are introduced for Terahertz (THz) absorption signatures detection of biomolecules in aqueous solution. Thousands of rectangular microchannels with a characteristic dimension of 2 μm and their reservoirs were precisely etched in a high resistivity silicon wafer by lithography and etching process, then the silicon wafer and a glass sheet were bonded to form a sealed microfluidic chip by anodic bonding technology. The chip can be sampled through the capillary action and the microfluidic pressure system. Three absorption signatures around 850, 928, 950 GHz of dissolved λ-DNA were obtained in 0.7∼1.0 THz band by using this chip and the coherent photomixing spectrometer. It is indicated that dispersion of biomolecular solution in 2 μm spaces between the tines of the grating in microchannels can reduce the water component in THz transmission detection, thereby reducing the water background absorption, effectively improve the signal strength of THz characteristic attenuation.