Molecular Printing: Solving the
sub-100 nm Soft Matter Conundrum
Department of Chemistry,
New York University
We have developed an arsenal of
strategies based on a recently developed scanning probe molecular
printing method, namely polymer pen lithography (PPL), to form
arbitrary patterns of molecular and biological species with
nanometer-to-micrometer feature size control. PPL employs
massively-parallel arrays of elastomeric tips to print arbitrary
patterns of molecular inks. The precise feature size control of
PPL arises from quantitative models relating dwell-time of the tips on
the surface and the pressure exerted by the tips on the surface.
Moreover, these relationships allow the precise leveling of the tip
arrays with repect to the substrate surface, so that feature variation
of less than 2% across a 1 cm2 areas can be achieved.
Importantly, the molds used to fabricated the PPL pen arrays can also
serve as inkwells, and as a result, multiplexed patterns can be readily
created using these methods. These tools have been used to explore the
concept of directed assembly, which has been employed to assemble a
variety of devices, including biosensors and molecular tunnel
junctions. We anticipate that these strategies will result in a
suite of new molecular printing methods that move us towards the goal
of a “desktop fab,” in which reproducible, nanoscale
patterns can be printed over large areas without necessitating large
capital investment or clean-room conditions.