Another technique used for fabrication of the thermoplastic polymers with microfluidic channel cavities is laser ablation, which is applicable to many polymers such as PC, COC/COP, PMMA, PS, nitrocellulose, PET, PETE, and Teflon . In this method, short laser pulses in the ultraviolet (UV) region (~200 nm wavelength) breaks the polymer chains. The decomposed polymer fragments such as CO2 and CO gas and polymer molecules are subsequently ejected due to the induced shock waves leaving photo-ablated cavities . Patterning the microchannel arrays can be conducted by using photo masks in the process resulting in straight vertical walls without any significant thermal damage. It should be noted that laser ablation in the UV wavelength cannot be used for thermoplastic polymers such as COC/COP due to their low UV absorption. Thus, infrared lasers such as CO2 or Nd:YAG laser systems should be adopted for microchannel formation.