The Helium Ion Microscope as a Tool for Imaging and Modification of Nanostructures, 2D Materials, and SARS-CoV-2 infected Cells

Armin Gölzhäuser / University of Bielefeld

October 7, 2021, 2 - 3 pm CEST

Online live talk

Introduction

The helium ion microscope (HIM) utilizes a focused beam of helium ions to image and modify materials with high spatial resolution, large depth of field, and chemical sensitivity [1]. HIM images show stronger chemical and topographical contrasts than images from the related scanning electron microscope, and the HIM is capable to resolve sub-nanometer features. Due to its charge compensation capability, the HIM can image insulating biological samples without additional conductive coatings. The presentation will contain examples of HIM imaging of nanomaterials, like 1 nm thick carbon nanomembranes (CNMs), 2D materials, and biological cells [2]. In an exploratory HIM study of SARS-CoV-2 infected Vero E6 cells, interactions between cells and virus particles, as well as among virus particles, could be imaged [3]. The HIM pictures show the three-dimensional appearance of SARS-CoV-2 and the surface of Vero E6 cells at a multiplicity of infection of approximately 1 with great morphological detail. The absence of a conductive coating allows a distinction between virus particles bound to the cell membrane and virus particles lying on top of the membrane. When applying higher ion currents, the HIM can be also used for the modification and the milling of materials. The capability of the HIM for nanolithography will be shown by examples of milling CNMs and graphene, where nanopores with diameters down to 1.3 nm were fabricated [4].

[1] Hlawacek, G.; Gölzhäuser, A., Eds. Helium Ion Microscopy, Springer International Publishing: Cham, Switzerland, 2016.

[2] Schürmann, M.; Frese, N.: Beyer, A.; Heimann, P.; Widera D.; Mönkemöller, V.; Huser, T.; Kaltschmidt, B.; Kaltschmidt, C.; Gölzhäuser, A. Helium Ion Microscopy Visualizes Lipid Nanodomains in Mammalian Cells, Small 2015, 43, 5781–5789.

[3] Frese, N.; Schmerer, P.; Wortmann, M.; Schürmann, M.; König, M.; Westphal, M.; Weber, F.; Sudhoff, H.; Gölzhäuser, A.: Imaging of SARS-CoV-2 infected Vero E6 Cells by Helium Ion Microscopy, Beilstein J. Nanotechnol. 2021, 12, 172–179.

[4] Emmrich, D.; Beyer, A.; Nadzeyka, A.; Bauerdick, S.; Meyer, J. C.; Kotakoski, J.; Gölzhäuser, A.: Nanopore Fabrication and Characterization by Helium Ion Microscopy, Appl. Phys. Lett. 2016, 108, 16310.

Armin Gölzhäuser

Armin Gölzhäuser studied physics at the University of Heidelberg and at the Arizona State University. In 1993 he received his Ph.D. in Physical Chemistry with Prof. Michael Grunze from the University of Heidelberg. From 1994-1996 he was a Feodor Lynen Fellow at the University of Illinois at Urbana-Champaign with Prof. Gert Ehrlich. He then returned to Heidelberg where he received his habilitation in 2001. In 2003 he became an associate professor of physical chemistry at the University of Marburg. Later in the same year, he became a full professor of physics at the University of Bielefeld, where he holds a Chair of Supramolecular Systems and Surfaces. Armin Gölzhäuser's research is focused on the fabrication, characterization and application of low dimensional nanostructures, membranes, and exploration of charged particle microscopy. His laboratory operates modern analytical tools, among them electron microscopes, photoelectron spectrometers, scanning probes and the first helium ion microscope at a German university. He has a strong interest in the technological application of nanostructures, and in 2011 he founded CNM Technologies GmbH, a company dealing with applications of carbon nanomembranes.  He is a founder of the Bielefeld Institute for Nanoscience (BINAS), Associate Editor of the Beilstein Journal of Nanotechnology, and a fellow of the American Vacuum Society (AVS).

Armin Gölzhäuser has co-edited the thematic issue "Focused particle beam-induced processing" in the Beilstein Journal of Nanotechnology.