Abstract

The recent development of techniques to fabricate microcellular polystyrene¹ and TPX² foams with densities between 0.01 and 0.20 g/cm³ has led to the investigation of their use in applications as diverse as artificial skin and blood vessels, inertial-confinement fusion targets, laboratory x-ray laser media, filters, catalytic substrates, and model porous media. The successful development of many of these applications requires machined shapes with features comparable to the 1 -20-μm cell size of the foam. Results that we have obtained on the interaction of 248- and 266-nm laser radiation with these new low-density materials show that ultraviolet laser ablation is an attractive technique for obtaining the required feature sizes. The morphology and chemical composition of the ablated surface are determined by the incident lase fluence and by the ultraviolet absorption spectrum of the foam. Photochemical and thermal effects were apparent in SEM, ESCA, laser Raman, and RBS measurements as well as in time-resolved optical emission spectra of the plume above the ablated surface. The results we have obtained on the ablation properties of well-characterized polystyrene and TPX foams can be directly applied to the biological materials they simulate.

© 1986 Optical Society of America