Fabrication of Crack-free Glass Microfluidic Chips with Tape-assisted Laser Engraving

Glass microfluidic chips could be used for the detection of fluorescent molecules, since they have no auto-fluorescence background. Laser engraving is a low cost, simple and flexible tool to fabricate microstructures into glass substrates; however, cracks are always formed near the microchannel during laser engraving because of non-uniform thermal stress distribution. In this work, we portrayed a simple method to avoid the formation of cracks by employing the commonly used adhesive tape. With the protection of adhesive tape, microchannels could be fabricated without any cracks at laser power less than 30%. The effect of laser parameters (laser power, scanning speed, and scanning passes) on the width and depth of the microchannel was investigated. To fully bonded the chip with perm-selective membrane, the influence of bonding pressure on the channel deformation and leakage area was analysed by numerical simulation. The final protein enriching experiments demonstrated the practicability of the proposed fabrication method.