Nanoparticles may pose risk during laser ablation

Health and environmental risks associated with exposure to nanoparticles have been an ongoing concern for the scientific community.

Jul 1st, 2007

Health and environmental risks associated with exposure to nanoparticles have been an ongoing concern for the scientific community (see www.laserfocusworld.com/articles/234080). Scientists at Laser Zentrum Hannover (LZH; Hannover, Germany) have now quantified the amount of nanoparticles generated during femtosecond laser micromachining in the hopes that this knowledge can lead to protective measures.

The LZH scientists found that an 800 nm femtosecond laser emitting pulses with a 150 fs duration at energies up to 1 mJ at a repetition rate of 1 kHz has a nanoparticle generation rate up to 100 times higher than that resulting from Nd:YAG laser ablation (per pulse and surface, at the same fluence). For example, 90% of the particles produced during femtosecond-laser ablation of zirconia or titanium are smaller than 85 nm, compared to particle sizes of approximately 100 nm up to several microns for CO2- or Nd:YAG-laser ablation of metal, ceramic, and organic materials. Within one laser-manufacturing shift, the generated nanoparticles may accumulate to a concentration that is 200 times larger than the background concentration. As the average output power increases for femtosecond lasers, toxicology studies will be needed to adequately assess nanoparticle risk. Contact: Stephan Barcikowski at s.barcikowski@lzh.de.

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