It is often said that beauty is in the eye of the beholder. In Microscopy it can simple be hidden and putting together the correct configuration may uncover beautiful secrets. A small strip of plastic wrap used for food packaging will look just like a regular transparent plastic if you use standard brightfield conditions but…. What happens if you use Polarization?
Polarized light microscopes are designed for the examination of birefringent samples. A material is consider birefringent when
its optical properties allow light propagation in two directions, on which the refractive index is different.
Birefringence is mainly present on crystals and minerals, but can also be find in liquid crystals, biological specimen and polymers, as in the case of this plastic wrap.
Pictures taken with a BA310POL and a Moticam 3
Objective magnification 4X
The sample is a plastic wrap containing polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET)