Dip-Pen Nanolithography Simulator

Dip-pen nanolithography drags an AFM tip coated with ink molecules across a substrate; a nanoscale water meniscus that condenses between tip and surface carries the ink down by diffusion. This simulator renders that meniscus and tip in 3D above a gold substrate and computes real feature sizes from the same transport-limited physics used in the lab: a point-source diffusion law r(t) = √(4Dt) for stationary dots, and a speed-dependent line-width model for continuous scanning. Switch between three ink classes spanning three orders of magnitude in diffusivity, dial relative humidity to grow or shrink the meniscus, and watch dwell time or tip speed directly control how large the written feature ends up — exactly the two knobs a real DPN operator uses to pattern sub-100 nm biosensor arrays.