A rapid and easy procedure of conductive 3D nanofibrous structure induced by nanosecond laser processing of Si wafer coated by Au thin-film

Many biomedical sensing applications require high electrical sensitivity as well as a method to control and implement them into biological applications. This requires a material to have both conductive and biocompatible properties. Many conductive materials fail in these applications due to their lack of biocompatibility, and many biocompatible materials have very low conductivity. A method to control the conductivity of fibrous silicon through the laser processing of silicon covered with a thin film of gold (1 μm) is detailed in this article. An Nd:YAG pulsed nanosecond laser was utilized to process the thin film at a line spacing of 0.025 mm at different overlaps (number of laser beams scanning through the same path), for increasing the surface to volume ratio and biocompatibility of the single crystalline silicon. The biocompatibility assessment has shown positive results with traces of the elements necessary for the formation of hydroxyapatite. Samples processed at a lower power showed higher concentrations of these trace elements, suggesting an increase in biocompatibility. Overall, this research offers preliminary findings as to the direction and future work that can be done with porous silicon to offer a cost effective and efficient method of enhancing the conductivity and biocompatibility for biomedical sensing and conductive tissue engineering applications.