Liquid metal wires supported on substrates destabilize into droplets. The destabilization exhibits many characteristics of the Rayleigh–Plateau model of fluid jet breakup in vacuum. In either case, breakup is driven by unstable, varicose surface oscillations with wavelengths greater than the critical one (λc). Here, by controlling the nanosecond liquid lifetime as well as stability of a rivulet as a function of its length by lithography, we demonstrate the ability to dictate the parallel assembly of wires and particles with precise placement.