title: Investigation of Nanoscale Interactions by Means of Subharmonic Excitation.
abstract: Multifrequency atomic force microscopy holds promise as a method to provide qualitative and quantitative information about samples with high spatial resolution. Here, we provide experimental evidence of the excitation of subharmonics in ambient conditions in the regions where capillary interactions are predicted to be the mechanism of excitation. We also experimentally decouple a second mechanism for subharmonic excitation that is highly independent of environmental conditions such as relative humidity. This implies that material properties could be mapped. Subharmonic excitation could lead to experimental determination of surface water affinity in the nanoscale whenever water interactions are the mechanism of excitation.
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Matteo
authors: M
authors: Chiesa
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Karim
authors: K
authors: Gadelrab
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Marco
authors: M
authors: Stefancich
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Peter
authors: P
authors: Armstrong
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Guang
authors: G
authors: Li
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Tewfik
authors: T
authors: Souier
authors: ‡Department of Oral Biology and School of Physics and Astronomy, University of Leeds, LS2 9JT, United Kingdom.
authors: Neil H
authors: NH
authors: Thomson
authors: §Departament de Disseny i Programació de Sistemes Electrònics, UPC - Universitat Politècnica de Catalunya, Av. Bases 61, 08242 Manresa, Spain.
authors: Victor
authors: V
authors: Barcons
authors: §Departament de Disseny i Programació de Sistemes Electrònics, UPC - Universitat Politècnica de Catalunya, Av. Bases 61, 08242 Manresa, Spain.
authors: Josep
authors: J
authors: Font
authors: ⊥Centre d' Investigació en Nanociència i Nanotecnologia (CIN2) (CSIC-ICN), Esfera UAB, Campus de la UAB, Edifici CM-7, 08193-Bellaterra, Catalunya, Spain.
authors: Albert
authors: A
authors: Verdaguer
authors: #Asylum Research UK Ltd, Commerce House, Telford Road, Bicester, Oxfordshire OX26 4LD, United Kingdom.
authors: Michael A
authors: MA
authors: Phillips
authors: †Laboratory of Energy and Nanosciences, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates.
authors: Sergio
authors: S
authors: Santos
keywords: AFM; capillary interaction; detection; nanoscale; subharmonics