Nanopatterned surfaces have numerous applications, ranging from cell growth to biosensing to data storage. However, traditional nanotechnology methods can be time-consuming and expensive, often requiring cleanroom processing and complicated procedures. Also, many nanoscale features are fragile; they can be highly sensitive to mechanical, thermal or chemical stresses.
These barriers have slowed the adoption of nanopatterning in many research fields. To make nanopatterned surfaces more widely applicable, a different approach is required. Ideally, the process should be simple and inexpensive, and able to deliver robust nanoscale patterns that can be employed in a variety of applications. Nanoislands achieve many of these goals.
In their study, the researchers used three common pattern transfer materials to demonstrate the robust nature of the nanoisland material across a broad range of temperatures, solvents and pressures. The nanoislands are stable up to 1000 °C, are much stronger than PDMS, photoresists and silicon, and also resist common solvents, acids and bases.
The nanoislands are formed by depositing a thin layer of gadolinium-doped ceria onto a single crystal of yttria-stabilized zirconia and then annealing. After annealing, the nanoislands self-assemble into various morphologies depending on the heat-treatment conditions and on the film deposition parameters. The islands can cover large areas, limited only by the size of the crystal substrate. Processing occurs outside a cleanroom environment.
Versatile platform
Applications for nanoislands and nanowells include DNA separations, nanoparticle manufacturing, cell adhesion and growth, and superhydrophobic surfaces.
Future work is focusing on developing even simpler processing methods. The goal is to make the process accessible to as broad a community of researchers as possible. For those applications that require well aligned and regular features, the team is working on improving large-scale alignment of features and periodicity. Combinations of micro and nanoscale features are also being explored.