In a ground-breaking study from 2013, Swedish scientists from KTH Royal Institute of Technology in Stockholm showed that people can detect nano-scale wrinkles while running their fingers over a seemingly smooth surface.⁠ ⁠ The study marked the first time that scientists quantified how people feel in terms of physical property. One of the authors, Mark Rutland, Professor of Surface Chemistry, said that the human finger can discriminate between surfaces patterned with ridges as small as 13 nanometers in amplitude and non-patterned surfaces.⁠ ⁠ ⁠ ⁠ ⁠ #fingers #science #biology #nanoscale #senses #study