Wednesday  |  Conference Center A  |  09:00 AM–09:40 AM

#13600, Keynote: Toward Understanding of Nanoscale Adhesion Using In situ Experiments in a Transmission Electron Microscope

Nanoscale adhesion is critical for advanced technologies, such as nanoparticle catalysts on support structures and nanoscale components in devices. Additionally, nanoscale interfacial behavior plays a critical role even in large-scale adhesion, because of surface roughness and contacting asperities. This talk will focus on recent work to understand the atomic-scale physics governing nanoscale adhesion, using in situ adhesion tests performed inside of a transmission electron microscope. The first part of the talk will focus on the load-dependence of adhesion in nanoscale probes composed of silicon, carbon, and titania. In this investigation, more than 150 in situ adhesion tests and molecular dynamics simulations were used to couple Angstrom-scale characterization of the probe’s size, shape, and structure together with nanonewton-scale measurements of adhesive forces. The results demonstrate the role that applied load plays in modifying the adhesive interaction, in ways that are not captured accurately in traditional contact models. The second part of the talk will focus on applying this understanding of nanoscale adhesion to nanoparticles, where the adhesion energy governs not only their attachment to supporting structures, but their performance and stability over time. Taken together, these investigations help to elucidate the atomic-scale interaction mechanisms at interfaces, and provide guidance for the measurement, modeling, and tailoring of adhesion in nanoscale devices.

Tevis Jacobs   University of Pittsburgh