March 5, 2018

Gentle High Speed Atomic Force Microscopy using Encased Cantilevers and Spiral Scanning

Abstract: 

Scanned Probe Microscopy excels at nondestructively probing samples in-situ with high resolution. However, it has been plagued with very poor temporal resolution and insufficient spatial resolution to probe molecular details when operating in liquid. In my group, we have extended the boundaries of SPM characterization by developing new probes for liquid environments that give an order of magnitude higher sensitivity. Encased cantilevers use a hydrophobic encasement to trap an air bubble around the cantilever and reduce damping while keeping the sample hydrated increasing sensitivity and resolution. We have also developed spiral scan algorithms that enable higher frame rates on large scanners providing the flexibility of large scan areas with near video rate imaging speeds. I will give a comparison of various scan waveforms and how they match scientific needs from the instrument.

Biography

Paul Ashby received his PhD in physical chemistry in 2003 from Harvard University studying intermolecular energy landscapes. He joined the Molecular Foundry at Lawrence Berkeley National Laboratory as a jump-start postdoc in the Imaging and Manipulation Facility and in 2007, he became a Staff Scientist. His research group aims to design materials whose nanoscale structure improves their functional properties. They use imaging techniques to spatially resolve physical and chemical properties and rely heavily on Atomic Force Microscopy (AFM) because it nondestructively probes the surface of materials in-situ. To more accurately measure function, he has invented technologies to improve AFM’s temporal resolution and sensitivity in liquid. Presently, the group has projects investigating photovoltaics, biomimetic mechanical materials, and reconfigurable films at liquid-liquid interfaces. He is also cofounder and coCEO of Scuba Probe Technologies LLC an AFM probe manufacturer.