Gel-based profilometry is non-invasive and only needs pressure to be applied to the surface of interest to get the image. Above is the surface topography of the back of a human hand. The pores are evident as small blue regions with low elevation. Long flexible structures like hairs will be pressed flat by the sampling gel, as seen in the hairs above. Image: Dylan Wainwright.

Gel-based profilometry is non-invasive and only needs pressure to be applied to the surface of interest to get the image. Above is the surface topography of the back of a human hand. The pores are evident as small blue regions with low elevation. Long flexible structures like hairs will be pressed flat by the sampling gel, as seen in the hairs above. Image: Dylan Wainwright.