AVS 62nd International Symposium & Exhibition
    Nanometer-scale Science and Technology Monday Sessions
       Session NS-MoM

Invited Paper NS-MoM5
Directing Nanoscale Mass and Energy Transport using Cantilever-Free Scanning Probes

Monday, October 19, 2015, 9:40 am, Room 212B

Session: Nanotools and Nanodevices
Presenter: Keith A. Brown, Northwestern University
Authors: K.A. Brown, Northwestern University
D.J. Eichelsdoerfer, Northwestern University
C.A. Mirkin, Northwestern University
Correspondent: Click to Email
Advances in lithography have driven the information revolution by allowing semiconductor manufacturers to shrink integrated circuits at an exponential rate for nearly 50 years. Given the explosion of interest in biomedical research and engineering, a major challenge that must be addressed in the coming decades will be the difficulty in developing high quality techniques for patterning soft and bioactive materials at the nanoscale. Scanning probe techniques are poised to be a major player in this advance because they allow one to direct mass transport at the nanoscale, thus attaining high resolution without processing steps that might damage biological materials. Despite their promise, the chief limitation inherent to scanning probe techniques is throughput, as patterning with a single probe is in many cases prohibitively slow. Recently, it has been shown that this problem can be circumvented by replacing the cantilever that conventionally supports a single probe with an elastomeric film on a rigid surface that supports a massive array of probes. While this new cantilever-free architecture intrinsically addresses the scalability challenge, many questions remain about how these probe arrays differ from their cantilever-based counterparts, specifically relating to how the transfer of energy and materials is governed by the hard/soft composite probe array. Here, we explore such transfer processes including the transport of liquids and light from cantilever-free tips to a surface. Specifically, we overview the transfer of polymeric solutions from a tip to a surface and find that, in many cases, the details of materials transfer are dictated by how the capillary bridge between the tip and surface ruptures. This observation allows for the patterning of sub-20 nm polymer features. Ultimately, however, our work is motivated by the desire to answer previously inaccessible questions through the development of new synthetic techniques. Thus, we explore these probe arrays as candidate techniques for performing massive-scale combinatorial experiments in nanoscience, and develop new methods for pushing the state-of-the-art in terms of ink complexity, feature size, and feature density. Based upon these advances, we describe preliminary screening experiments for the identification of novel nanoparticle-based heterogeneous catalysis. This work sets the stage for scanning probe-based tools to fill many emerging needs in nanoscience, biology, and materials science.