Improving performances of microchannels in microfluidic chip using solidifiable adhesive film

In order to improve surface roughness and hydrophilicity of microchannels in microfluidic chip, then to achieve high fluid speed under small pressure, a technology named as coating solidifiable adhesive film is proposed. In this paper the microfluidic chip is manufactured using CO₂ laser. The film is coated on inside wall of microchannels using ultraviolet optic solidifiable adhesive. Two coating methods were used to synthesise the NOA61 film. The surface roughness and water-phase contact angle of the microchannel with and without the NOA61 film are measured. The roughness is reduced from 2 μm to 243·36 nm and the contact angle is reduced from 100 to 72·55°, when NOA61 film is coated with the action of gas blowing and consequent drying by UV light. The roughness is reduced from 2 μm to 60·49 nm and the contact angle is reduced from 100 to 55·35°, when NOA61 film is obtained by gravity flow.