Advances in Ambient and Liquid AFM - Nanoscale Structure and Dynamics

By Roger Proksch

Published on

Abstract

In 1986, the Atomic Force Microscope was invented,[1] opening a window beyond the diffraction limit of optics onto the nanoscale world. From the beginning, researchers were captivated by the possibilities of “smallifying” existing laboratory techniques to the newly accessible nanometer length scale, perhaps most memorably captured by the phrase “lab on a tip”.[2]

In this talk, we will explore some recent results in observations of structure and dynamics in a variety of systems ranging from polymer dynamics in ambient conditions, 3D atomic resolution mapping of the structure of the solid-liquid interface, defect dynamics in crystal lattice and biologically relevant materials and molecules in fluid. In particular, dynamics can now be captured at frame rates ranging from >1,000 seconds/image to <100 milliseconds/image.

One of the most natural extensions beyond topography – given that the cantilever tip touches the sample surface – is stiffness and modulus measurements. While there are numerous techniques for quantifying elastic and inelastic properties with the AFM, we will focus on Bimodal AFM theory[3] and experiments[4] where more than one resonant vibrational mode of the cantilever is used. In particular, bimodal AFM has allowed very high-resolution and high-speed modulus measurements on a wide variety of samples ranging from soft gels and polymers to much stiffer metals and ceramics, ranging from less than 10 MPa to >100 GPa. Notably, these measurements can cover greater than three orders of magnitude in modulus with the same cantilever, both in ambient and fluid conditions. These measurements are in part enabled by photothermal actuation[5] and a new interferometric detection scheme[6] that allows calibration of the frequency-dependent cantilever sensitivity and stiffness.

Bio

Roger Proksch Dr. Roger Proksch, CEO and co-founder, Asylum Research, Oxford Instruments Fellow

1989-1993: PhD Physics at University of Minnesota
1997-1999: Director of Magnetics Research at Digital Instruments
1999-2012: Co-founder and President of Asylum Research, state-of-the-art SPM and AFM development & manufacturing
2012-Present: CEO of Asylum Research, an Oxford Instruments Company

  • Key contributor to the design and development of the MFP-1D, MFP-3D, Origin, Infinity, Cypher S and Cypher ES and Cypher VRS atomic force microscopes. Asylum systems have been recognized as the technology leading AFMs worldwide over the past 15 years.
  • Leading Asylum Research from its founding in 1999 with revenue of 0$, through an acquisition by Oxford Instrumentsand to the present.
  • Designed several novel application-specific options, accessories and experimental methods for the Asylum AFM product line, resulting in over seventy scientific publications and ten book chapters.
  • Inventor on 33 issued patents with more pending; portfolio includes innovative products and applications.
  • Collaborative efforts with customers which resulted in numerous awards including the Microscopy Today innovation Award, Roland B. Snow Award, Frost and Sullivan award, Technological Innovation Prize and multiple R&D 100 Awards.

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References

  1. Binnig, Quate, and Gerber, Physical review letters 56 930 (1960).
  2. Meyer, Ernst, Hans J. Hug, and Roland Bennewitz. Scanning probe microscopy: the lab on a tip. Springer Science & Business Media, 2013.
  3. T. T. Todriguez and R. Garcia, Appl. Phys. Lett. 84, 449 (2004).
  4. T. Proksch, Appl. Phys. Lett. 89, 113121 (2006).
  5. A. Labuda et al, Rev. Sci. Instrum. 83, 053702 (2012).
  6. A. Labuda and R. Proksch, Appl. Phys. Lett. 106 253103 (2015).

Cite this work

Researchers should cite this work as follows:

  • Roger Proksch (2017), "Advances in Ambient and Liquid AFM - Nanoscale Structure and Dynamics," https://nanohub.org/resources/27698.

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Time

Location

1055 WALC, Purdue University, West Lafayette, IN