We here present a method for fabrication of multi-level all-polymer chips by means of silicon dry etching, electroplating and injection molding. This method was used for successful fabrication of microfluidic chips for applications in the fields of electrochemistry, cell trapping and DNA elongation. These chips incorporate channel depths in the range between 100nm and 100μm and depth to width aspect ratios between 1/200 and 2. Optimization of the sealing process of all-polymer COC microfluidic chips by means of thermal bonding is also presented. The latter includes comparing the bonding strength of UV-treated foils and presentation of a simple model for estimating the delamination pressure. With UV surface treatments, foils of 100μm thickness were found to withstand pressures up to 9atm in Ø4mm cylindrical inlets when thermally bonded to micropatterned substrates of 2mm thickness.
Microelectronic Engineering, 2013, Vol 111, p. 294-298