3D print an electron micrograph of the surface of a relatively simiple geometric virus like the mumps virus out of a spongey, tactile, resilient material and it will act as a precise interface. The nooks and crannies on viral surfaces are arranged in a series of interferring spirals, like pine cones, but the spirals suck your hand right into them as you wing the print around, I guess because that is what they are designed to do -- interface spirally with other things that are engineered according to this interfering spiral principle, like humans for one.
-- JesusHChrist, Dec 05 2016

random, halfbakery