Micro-Swelling and penetration assisted laser Processing: A doping and laser processing method for polydimethylsiloxane films based on swelling and penetration behavior

Abstract

Polydimethylsiloxane and its laser processing have significance in broad fields. The problems caused by poor absorption and current doping methods have prevailed in the laser processing of polydimethylsiloxane. Here, a simple and efficient dopant-induced laser processing method based on the swelling and penetration behavior was presented to improve the laser processing of polydimethylsiloxane films: micro-swelling and penetration assisted laser processing. In this method, the dopant benzophenone was introduced into polydimethylsiloxane films through micro-swelling and penetration pretreatment to adjust its physical/chemical properties so as to improve the laser processing. Results showed that micro-swelling and penetration assisted laser processing method performed higher efficiency, capability (Depth: 625.9 ± 38 μm, Width: 13.2 ± 0.9 μm, Aspect Ratio: 47.4 ± 1.7:1) and quality (no debris or micro-crack and less thermal effects) compared to the typical laser processing method (Depth: 140.1 ± 5.7 μm, Width: 28.0 ± 2.0 μm, Aspect Ratio: 5.0 ± 0.4:1). The introduction of benzophenone changed the polydimethylsiloxane films’ optical, photochemical and thermodynamic properties and affected its laser ablation process, in which the more complete and uniform photochemical decomposition of polydimethylsiloxane films was promoted due to that benzophenone molecules absorbed photon energy and decomposed, and transferred energy to polydimethylsiloxane. Moreover, this method hardly influenced the original properties of polymer films due to the removability of dopants.