Process engineering design relies on a host of mechanical devices
that enable transport phenomena to take place under controlled conditions. These devices include pipes, valves, pumps,
chemical reactors, heat exchangers, packed columns, etc. Mass, energy, and momentum transfer will
also be essential phenomena in nano-process engineering, particularly at the
interface between micro and nanodevices.
Control valves are one of the most fundamental components. In this paper we explore the design of a
silicon cantilever valve for fluid transport control at the molecular level
(32.5-55 nm in length). We utilize
design elements that can be synthesized with existing or emerging chemical
methods. Thus, the valve is constructed
with functionalized silicon surfaces, single-wall carbon nanotubes, and organic
monolayers. While Molecular Mechanics
design limitations were overcome with help from classical engineering
approximations, non-linear effects, such as nanotube crimping (for an in-line
valve design), are accounted for through full-physics atomistic simulations. Optimal
design geometries and operating deflection ranges have been estimated for a
device containing over 75,000 atoms.