Presently, a DST-sponsored project on the laser-mediated fabrication of poly vinyl alcohol (PVA)-based microchannels is underway. The polymeric film is in-situ dispersed with the transition metals- (Fe/Ni/Ag/Cu-) grown carbon nanofibers (CNFs). CNFs will be grown on activated carbon microfibers (ACF) substrate by chemical vapor deposition (CVD) using metal nanoparticles (~50 nm) and incorporated within the polymeric film during a polymerization stage. The pulsed nanosecond excimer UV laser will be used to create microchannels (250 µm long x 75 µm wide) in the polymeric films (~ 1 mm thick).

The fabrication-parameters such as pulse energy, pulse-frequency, and scanning speed will be optimized. By this technique, the nanometal particles and ACFs/CNFs dispersed within the film are exposed to the surrounding aqueous phase through the porous walls of fabricated microchannels, when the film is brought in contact with water to be treated. In addition to providing large adsorptive/catalytic surface area, the dispersed carbon fibers enhance the mechanical strength of the polymeric film. The application of the fabricated microchannels in the purification of water includes arsenic and phenol removal and microbial (*E. coli* and *S. aureus*) control.