Rapid prototyping of glass microfluidic devices using femtosecond laser pulses

Laser micromachining technology with 150 femtosecond pulses is developed to fabricate glass microfluidic devices. A short theoretical analysis of femtosecond laser ablation is reported to characterize the femtosecond laser micromachining. The ablated crater diameter is measured as a function of the number of laser pulses as well as laser fluence. Two different ablation regimes are observed and the transition between the regimes is dependent on both the laser fluence and the number of laser shots. Based on the ablation phenomena described, microfluidic devices are fabricated with commercially available soda lime glasses (76 nun x 26 trim x I mm, Knittel Glaser, Germany). In addition to a microchannel for microfluidics, the capillary as well as optical fiber for detecting is integrated on the same substrate. The substrate is successively packaged with a lid slide glass by a thermal direct bonding. The presented developments are suitable for fast turn-around design cycle and inexpensive procedure, which provide rapid prototyping of MEMS devices.