Nanoscientists create patterns using flexible plastic sheets

18-Aug-10

A team of nanoscientists from Northwestern University is using flexible plastic sheets as the backbone of a new inexpensive way to create, test and mass-produce large-area patterns on the nanoscale. It is a simple, low-cost and high-throughput nanopatterning method that can be done in any laboratory. The method offers unprecedented opportunities to manipulate the electronic, photonic and magnetic properties of nanomaterials. It also easily controls a pattern's size and symmetry and can be used to produce millions of copies of the pattern over a large area. Potential applications include devices that take advantage of nanoscale patterns, such as solar cells, high-density displays, computers and chemical and biological sensors. No other existing nanopatterning method can both prototype arbitrary patterns with small separations and reproduce them over six-inch wafers for less than US$100. Starting with a single master pattern, the simple yet potentially transformative method can be used to create new nanoscale masters with variable spacings and feature sizes. SANE can increase the spacing of patterns up to 100% as well as decrease them down to 50% in a single step, merely by stretching or heating (shrinking) the polymer substrate (the Shrinky Dinks material). Also, SANE can reduce critical feature sizes as small as 45% compared to the master by controlled swelling of patterned polymer molds with different solvents. SANE works from the nanoscale to the macroscale. Biologists, chemists and physicists who are not familiar with nanopatterning can use SANE for research at the nanoscale. Those working on solar energy, data storage and plasmonics will find the method particularly useful. SANE offers a way to meet three grand challenges in nanofabrication from the same, and a single master pattern: (1) creating programmable array densities, (2) reducing critical feature sizes, and (3) designing different and reconfigurable lattice symmetries over large areas and in a massively parallel manner.