Thin Solid Films, Vol.453-54, 394-398, 2004
Millimeter long PMMA nanofibers - a new form of material removal in laser ablation
A new form of material removal in laser ablation is explained. Long (up to 1 mm) nanofibers with a radius approximately 150-200 nm are obtained when a polymethylmethacrylate (PMMA) target is irradiated with a single pulse of a KrF excimer laser. The model suggests an expulsion of energetic droplets by an intense pressure of the plume to the exterior of the spot. For the transient melt of a polymeric viscous liquid resulting from UV laser excitation, such droplets provide the heads of the jets pulled from the melt bath, giving rise, after re-solidification, to nanofibers. The initial speed of fiber spinning is extremely high (840 m/s, maximum velocity) and unusual properties of the laser-produced nanofibers may be expected. (C) 2003 Elsevier B.V. All rights reserved.