Effect of nanosecond and femtosecond pulse duration of laser processing of thin biodegradable polymeric film

Abstract

The study of the effect of nanosecond and femtosecond pulse duration of laser processing of a biodegradable poly(ε-caprolactone) (PCL) film was carried out PCL has a melting temperature of 60 °C and shows symptom of melting when processed with lasers. A very high energy and localized source of laser irradiation is required for effective material removal without melting. Nd:YAG laser with wavelength 355 nm and pulse duration of 7 ns and Ti:Sapphire femtosecond laser with wavelength 800 nm and pulse duration of 110 fs were used. The use of the femtosecond laser produced neat drilled-through holes with excellent repeatability while the Nd:YAG laser performed with fairly good repeatability due to symptoms of melt and occasional tearing of film as a result. The ablated surface of the film was studied and the morphological features were analyzed using phase contrast optical microscopy and scanning electron microscopy (SEM). The present study demonstrated that laser ablation using nanosecond and femtosecond pulse duration are able to achieve good micro-drilling on the PCL with high degree of success and precision. This paved the way for enhancement in membrane tissue engineering.