Mapping Elastic Properties of Heterogeneous Materials in Liquid with Angstrom-Scale Resolution

Abstract

Fast quantitative mapping of mechanical properties with nanoscale spatial resolution represents one of the major goals of force microscopy. This goal becomes more challenging when the characterization needs to be accomplished with subnanometer resolution in a native environment that involves liquid solutions. Here we demonstrate that bimodal atomic force microscopy enables the accurate measurement of the elastic modulus of surfaces in liquid with a spatial resolution of 3 Å. The Young's modulus can be determined with a relative error below 5% over a 5 orders of magnitude range (1 MPa to 100 GPa). This range includes a large variety of materials from proteins to metal-organic frameworks. Numerical simulations validate the accuracy of the method. About 30 s is needed for a Young's modulus map with subnanometer spatial resolution.

Fast, High Resolution, and Wide Modulus Range Nanomechanical Mapping with Bimodal Tapping Mode

“…A piece of Si wafer patterned with a ~200 nm thick Ti film 32 was cleaned by consecutive sonication in acetone (HPLC grade, Alfa Aesar, Ward Hill, MA), isopropanol (Gigabit, KMG 25 Chemicals Inc., Houston, TX) and ultrapure water (18.2 MΩ). The sample was dried with dry nitrogen and exposed to oxygen plasma for 1 min ( PE-IIA, Technics).…”

Fast, quantitative and high resolution mapping of viscoelastic properties with bimodal AFM

“…1,6,8,[16][17][18][19][20][21] Bimodal AFM provides a very fast, high resolution and accurate method to map the elastic properties of polymers and biomolecules. 22,23 It has been applied to determine with very high spatial resolution the elastic modulus of a large variety of materials and macromolecules such as antibodies 24 and other proteins, [25][26][27] DNA, 28,29 cells, 30,31 bone microconstituents, 32 lipid bilayers, 33,34 self-assembled monolayers, 35,36 2D materials 37 or organic semiconductor devices. 38 This technique can be operated in air or liquid.…”

Probing of Local Multifield Coupling Phenomena of Advanced Materials by Scanning Probe Microscopy Techniques

“…Figure shows the basic setups of some representative SPM techniques. The most used SPM techniques include contact/noncontact/tapping‐mode AFM, conductive AFM (C‐AFM) (Figure i), Kelvin probe force microscopy (KPFM) (Figure ii), electrostatic force microscopy (EFM), magnetic force microscopy (MFM), scanning thermal microscopy (SThM), electrochemical AFM (EC‐AFM), piezoresponse force microscopy (PFM) (Figure iii), electrochemical strain microscopy (ESM), contact resonance force microscopy (CR‐FM) (Figure iv), and multifrequency AFM such as AM–FM (amplitude modulation–frequency modulation) and bimodal AFM, and many others. Some of the SPM measurements results are illustrated in Figure .…”