Study on a low-cost and fast fabrication method of glass microfluidic chips

This paper describes a low-cost, fast process for the fabrication of glass microfluidic chips, in which commercially-available microscope glass slides (soda-lime glass) were used as substrate materials, and a layer of AZ 4620 positive photoresist was used as an etch mask for buffered oxide etching of soda-lime glass instead of using an expensive metal or polysilicon/nitride layer. Meanwhile, a fast but reliable UV-bonding process was developed to seal the channels rather than utilizing thermal fusion bonding. The whole process for most microfluidic devices (<50 mu m in depth) could be done within 3.5 h, which greatly decreases the time and cost of the fabrication of the glass microfluidic devices. Here the effects of the thickness of the photoresist, hardbake time and ratio of BOE on the fabrication of the glass microfluidic chips were also systemically investigated. Some optimum parameters were achieved for the fabrication process.