| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Thursday Sessions |
| Session NS+BI-ThA |
| Session: | Biomolecular Templates & Bioinspired Nanomaterials |
| Presenter: | E.O. Reimhult, ETH Zurich, Switzerland |
| Authors: | L. Isa, ETH Zurich, Switzerland E. Amstad, ETH Zurich, Switzerland M.H. Textor, ETH Zurich, Switzerland E.O. Reimhult, ETH Zurich, Switzerland |
| Correspondent: | Click to Email |
An interesting aspect of the self-organization in Nature resulting in precise patterning of hierarchically structured materials is that the “synthesis” and patterning of the materials occur at liquid amphiphilic interfaces such as membranes. That particles can be organized and change the properties of liquid interfaces has long been known and explored as e.g. Pickering emulsions in foams, food processing and other large-scale, bulk materials applications. However, self-assembly of nanometer-sized colloids with defined surface properties at liquid-liquid interfaces is also a process with huge potential for the fabrication of controlled two-dimensional nanoscale structures and patterns as well as “nanomaterials”. This is due to three key factors: a) the particles are trapped at the interface, but b) retain lateral mobility and c) exhibit specific interactions, which when properly understood and controlled lead to assembly of controlled structures. We have recently explored both how the oil-water interface can be used for unprecedented control of the assembly of nanoparticle patterns and transferred to substrates for low-cost nanolithography, and how tailored core-shell nanoparticles with functional cores can be assembled at such interfaces.
I will describe how self-assembly at the liquid-liquid interface (SALI) can be used for the deposition of non-close-packed crystalline arrays of NPs for lithographic masks and the physical control parameters for the successful application of this method. Our approach allows us to control the spacing of particles in a wide range; we have demonstrated reproducible and homogeneous patterns with spacing between 3 to 20 particle diameters using colloids from 40 to 500 nm over chip-sized areas. The use of bimodal size distributions at controlled ratios also allows for induced phase separation and thus hierarchically ordered patterns to emerge.
By optimization of a simple Schäfer-type deposition setup and the choice of the proper oil phase, the particle patterns can be transferred to a substrate with few limitations. We will demonstrate use of the deposited particle patterns to fabricate a range of nanostructures for electrochemical and nanoplasmonic biosensing which previously could not be fabricated by particle lithography, and this at a fraction of cost to other available patterning techniques.