Product Code: ICAL07_M1306

Picosecond Laser Micromachining of Biomedical Materials
Authors:
Assi Huttunen, Tampere University of Technology; FIN-33101 Tampere Finland
Petri Laakso, VTT Technical Research Centre of Finland; Lappeenranta Finland
Minna Kellomäki, Tampere University of Technology; Tampere Finland
Riku Heikkilä, Tampere University of Technology; Tampere Finland
Ville Ellä, Tampere University of Technology; Tampere Finland
Presented at ICALEO 2007

In this work, biodegradable polymers and bioactive glass were micro machined by UV-laser for application in biomedical engineering. Studied materials were poly(lactide-co-glycolide) (PLGA), drug loaded PLGA, oriented polylactide and bioactive glass. Laser micromachining of grooves and holes were studied using diode pumped Nd:YVO4 picosecond laser at 355 nm wavelength (Lumera GmbH, Germany). The repetition rate of 10200 kHz and machining speed of 351000 mm/s was used. The morphology, dimensional accuracy and surface condition of the samples after the laser ablation were studied using confocal laser scanning microscope, scanning electron microscope and optical microscope. Micro grooves and holes fabricated were at maximum 150230 µm deep. Small amount of debris was found around the machined grooves and holes which were tested to remove using ultrasonic washing. In the case of bioactive glass washing helped to remove debris making the surface smoother but it did not have any significant effect on PLGA, drug loaded PLGA or oriented PLA. Laser machining coloured drug loaded PLGA brown, due to the heat conduction to the sample. Colour change could also be caused by high energy laser which has somehow changed the structure of the drug. This work demonstrated that UV-laser micromachining is a well-suited technique for biomedical materials, such as biodegradable polymers and bioactive glass.