When I discovered that high-speed particles of ink were flying out of laser treated tattoos in 2012, I also found that many of these particles had been embedded in the glass slides.
Using an optical microscope I found that many of these ink particles looked like ‘insects’ – just like those in the movie Jurassic Park!
Below are a few of my photomicrographs for your pleasure…..
Note that the graduated marks visible in some of the above photos are 0.12mm apart,
giving an indication of the size of these particles.
Below you can see the same field of view at different depths of focus. This means that these particles have penetrated to different depths within the glass slide…
You can clearly see different particles coming into focus at different depths.
I think that these examples are showing ink that has melted as it hits the glass slide. The extreme change in kinetic energy, coupled with the already high temperature of the exploded fragments, raises the ink temperature to above its melting point. The ink smears then cools rapidly. Many of the above fragments appear to be quite symmetrical, suggesting this smearing action.
Here’s a few more of my ‘insects’….
The middle photo shows a mixture of surface ink particles – the ‘lumpy’ looking particles – and the deeper insects, which are not in focus.
At present, I am investigating whether these ink fragments are potentially carrying viable bacteria or virus particles. If so, they may represent a contamination hazard for tattoo laser operators! This would be very serious since it could cause infection transmissions. Fortunately, the glass slide technique prevents any possible transmission since the glass ‘captures’ all the high-speed fragments!!
Some of the above slides were supplied by Aaron Carr, Jim Duncan and Lesley Murphy. Many thanks to them for their help.