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The effect of AFM operation mode on O adatom contrast was investigated, and the interaction of O adatom and the subsurface defect was observed by AFM/STM. Multi-channel exploration was performed to investigate the charge transfer between the adsorbed O and the TiO2(110) by obtaining the frequency shift, tunneling current and local contact potential difference at an atomic scale. The tunneling current image showed the difference of the tunneling possibility on the single O adatom and paired O adatoms, and the local contact potential difference distribution of the O-TiO2(110) surface institutively revealed the charge transfer from TiO2(110) surface to O adatom. The experimental results are expected to be helpful in investigating surface/interface properties by SPM. *

Iridium-coated ultrastiff AFM cantilever SD-T10L100 from the NANOSENSORS Special Developments List (typical Force constant 2 000 N/m) were used in the presented study.

The cantilever tip was first degassed at approximately 650 K for 30 min and then cleaned by Ar ion bombardment to remove the contaminants, prior to the measurements. Features of the surface structure were related to the charge states of the tip apex, and a stable tip was essential to accurately characterize the surface structure and properties in the experiment. The imaging mode became stable in AFM experiments when the metal-coated Si cantilever was employed in the experiments. *

Please have a look at the NANOSENSORS blog for the full citation and a direct link to the full article.

#ScanningProbeMicroscopy #KPFM #nanomaterials #扫描探针显微镜探针 #原子力显微镜 #AFMカンチレバー

The reactivity is greatest on (001) surfaces (this is the orientation of the layers in this (110)p layered perovskite structure) while surfaces perpendicular to this orientation have the least reactivity. Complex domain structures were observed within the grains, but they appeared to have no effect on the photocathodic reduction of silver, in contrast to previous observations on other ferroelectrics. La2Ti2O7 is an example of a ferroelectric oxide in which the crystal orientation has a greater influence on the photochemical reactivity than polarization from the internal domain structure. *

NanoWorld™ conductive Platinum Iridium coated Arrow-EFM AFM probes were used for the Piezo-force microscopy (PFM) that was used to determine the ferroelectric domain structure on the surface. * https://www.nanoworld.com/electrostatic-force-microscopy…

The ferroelectric domains on the surface were found to have irregular shapes and there was no correlation between the pattern of silver reduction and the domain shape. The results indicate that the ferroelectric polarization of La2Ti2O7 does not alter the reactivity enough to overcome the influence of the anisotropic crystal structure. *

Please have a look at the NanoWorld blogpost for the full citation and a direct link to the full article.

#ferroelectricity #SurfaceOrientation #PiezoForceMicroscopy #压电力显微镜 #压电响应力显微镜探针 #PFMカンチレバー

It is manifested by a sharp anomaly in the magnetic susceptibility and the magnetic torque, distinct from other anomalies observed also in polar mono-domain samples upon transitions between the cycloidal, the Néel-type skyrmion lattice and the ferromagnetic states. *

The authors ascribe this additional transition to the transformation of distinct magnetic textures, confined to polar domain walls (DW), to the ferromagnetic (FM) state. The emergence of these DW-confined magnetic states is likely driven by the mismatch of different spin spirals, hosted by the adjacent domains. A clear anomaly in the magneto-current indicates that the DW-confined magnetic states also have strong contributions to the magnetoelectric response. *

The authors expect polar DWs to commonly host such confined magnetic edge states and, thus, offer a fertile ground to explore novel forms of magnetism. *

To characterize the polar domains and to estimate the density of DWs in GaV4Se8, K. Geirhos et al. combined several complementary scanning probe microscopy techniques, including non-contact atomic force microscopy ( nc-AFM ), scanning dissipation microscopy ( SDM ), and frequency-modulated Kelvin-probe force microscopy ( KPFM ). *

In attempt to observe spin cycloidal and Néel-type skyrmion textures within polar domains of GaV4Se8, only evidenced by small-angle neutron scattering measurements so far43, the authors of the article also carried out magnetic force microscopy (MFM) measurements. A second purpose of the MFM study was to explore possible magnetic states confined to the vicinity of DWs, as reported in GaV4S8. *

NANOSENSORS™ SSS-QMFMR high resolution magnetic AFM probes for ultra high vacuum conditions were used for the magnetic measurements with scanning probe microscopy. * https://www.nanosensors.com/supersharpsilicon-high-quality…

NANOSENSORS™ conductive wear-resistant Platinum Silicide AFM probes of the PtSi-FM type were used for all other measurements described in the article. * https://www.nanosensors.com/platinum-silicide-force…

Please have a look at the NANOSENSORS blog for the full citation and a direct link to the full article.

#multiferroics #MagneticProperties #KPFM #GaV4S8 #MFMprobes #physics

In the article “Carbon nanotube porin diffusion in mixed composition supported lipid bilayers” Kylee Sullivan, Yuliang Zhang, Joseph Lopez, Mary Lowe and Aleksandr Noy describe how they used high-speed atomic force microscopy (HS-AFM) and all-atom molecular dynamics (MD) simulations to study the behavior of CNTPs in a mixed lipid membrane consisting of DOPC lipid with a variable percentage of DMPC lipid added to it. HS-AFM data reveal that the CNTPs undergo diffusive motion in the bilayer plane.*

Motion trajectories extracted from the HS-AFM movies indicate that CNTPs exhibit diffusion coefficient values broadly similar to values reported for membrane proteins in supported lipid bilayers. The data also indicate that increasing the percentage of DMPC leads to a marked slowing of CNTP diffusion. MD simulations reveal a CNTP-lipid assembly that diffuses in the membrane and show trends that are consistent with the experimental observations. *

The above-mentioned study confirms that CNTPs mimic the major features of the diffusive movement of biological pores in lipid membranes and shows how the increase in bilayer viscosity leads to a corresponding slowdown in protein motion. It should be possible to extend this approach to studies of other membrane protein dynamics in supported lipid bilayers. The authors note that those studies, however, will need to be mindful of the challenge of unambiguous visualization of the membrane components, especially in systems that incorporate smaller proteins, such as antimicrobial peptides. Another challenge that could complicate these studies would be microscopic phase separation of the lipid matrix that could lead to complicated pore dynamics in the membrane. *

NanoWorld Ultra-Short AFM cantilevers with high-density carbon/diamond-like carbon (HDC/DLC) AFM tips of the USC-F1.2-k0.15 type were used for the high-speed atomic force microscopy described in the article. * https://www.nanoworld.com/Ultra-Short-Cantilevers-USC-F1.2…

Please have a look at the NanoWorld blog for the full citation and a direct link to the full article.

#HighSpeedAtomicForceMicroscopy #lipidbilayers #高速AFMプローブ #高速原子力显微镜探针

Recent studies explored their potential to be repopulated with human cells and thus highlight a growing interest for their use in tissue engineering or for biomedical applications. However, it is still unclear if these in vitro plant-based scaffolds can modify cell phenotype or affect cellular response to external stimuli.*

In the research article “Plant-Based Scaffolds Modify Cellular Response to Drug and Radiation Exposure Compared to Standard Cell Culture Models “ Jerome Lacombe, Ashlee F. Harris, Ryan Zenhausern, Sophia Karsunsky and Frederic Zenhausern report the characterization of the mechano-regulation of melanoma SK-MEL-28 and prostate PC3 cells seeded on decellularized spinach leaves scaffolds, compared to cells deposited on standard rigid cell culture substrate, as well as their response to drug and radiation treatment.*

In their study the authors show that plant decellularization provide soft scaffolds that match the stiffness range of most of the human tissue and modify cell behavior, including drug and radiation response, compared to standard cell culture models. Because of their distinguished features (natural vasculature, low immunogenicity, low cost, relative ease, etc.) and their wide variations in the shape and structures, these scaffolds offer a multi-controllable model with multiple biochemical and biophysical interactions. However, additional studies are required to determine if they could address important architectural and physical challenges of the in vivo tissue environment.

For force measurement, the Young’s Modulus (YM) of the leaf scaffolds were determined using force spectroscopy mode at liquid interface with NANOSENSORS uniqprobe qp-BioAC AFM probes for leaves measurement.* https://www.nanosensors.com/uniqprobe-uniform-quality…

Please have a look at the NANOSENSORS blog for the full citation and a direct link to the full research article.

#decellularization #forcemapping #biotechnology #AtomicForceMicroscopy #AFMカンチレバー #原子力显微镜

Noncovalent interactions can be triggered by external influences, such as the change of pH, light irradiation, thermal activation, introduction of a magnetic field, moisture, or redox response. Of high interest are light-responsive systems, for example in the fields of sensors or therapy, and, thus, it is desirable to explore novel concepts toward light-triggerable self-assembly.*

In the article “Photoresponsive Photoacid-Macroion Nano-Assemblies” Alexander Zika, Sarah Bernhardt and Franziska Gröhn present light-responsive nano-assemblies with light-switchable size based on photoacids.*

Anionic disulfonated napthol derivates and cationic dendrimer macroions are used as building blocks for electrostatic self-assembly. Nanoparticles are already formed under the exclusion of light as a result of electrostatic interactions. Upon photoexcitation, an excited-state dissociation of the photoacidic hydroxyl group takes place, which leads to a more highly charged linker molecule and, subsequently, to a change in size and structure of the nano-assemblies. The effects of the charge ratio and the concentration on the stability have been examined with absorption spectroscopy and -potential measurements.*

The influence of the chemical structure of three isomeric photoacids on the size and shape of the nanoscale aggregates has been studied by dynamic light scattering and atomic force microscopy, revealing a direct correlation of the strength of the photoacid with the changes of the assemblies upon irradiation.*

NanoWorld Ultra-Short AFM Cantilevers of the USC-F0.3-k0.3 type ( typical force constant 0.3 N/m ) were operated in tapping mode for the Atomic Force Microscopy (AFM) images presented in the article.* https://www.nanoworld.com/Ultra-Short-Cantilevers-USC-F0.3…

Please have a look at the NanoWorld blog for the full citation and a direct link to the full article.

#nanoassemblies #photoacid #polymers #materialsscience #AtomicForceMicroscopy #高速AFMプローブ #高速原子力显微镜

#characterization #surfacetopography #atomicforcemicroscopy

However, this scheme is energy consuming and may produce massive Joule heating. To reduce energy dissipation and risk of heightened temperatures of skyrmion-based devices, an effective solution is to use electric field instead of current as stimulus.*

In the article “Electric-field-driven non-volatile multi-state switching of individual skyrmions in a multiferroic heterostructure”, Yadong Wang, Lei Wang, Jing Xia, Zhengxun Lai, Guo Tian, Xichao Zhang, Zhipeng Hou, Xingsen Gao, Wenbo Mi, Chun Feng, Min Zeng, Guofu Zhou, Guanghua Yu, Guangheng Wu, Yan Zhou, Wenhong Wang, Xi-xiang Zhang and Junming Liu realize an electric-field manipulation of skyrmions in a nanostructured ferromagnetic/ferroelectrical heterostructure at room temperature via an inverse magneto-mechanical effect.*

Intriguingly, such a manipulation is non-volatile and exhibits a multistate feature. Numerical simulations indicate that the electric-field manipulation of skyrmions originates from strain-mediated modification of effective magnetic anisotropy and Dzyaloshinskii–Moriya interaction.*

The results presented in the article open a direction for constructing low-energy-dissipation, non-volatile, and multistate skyrmion-based spintronic devices.*

To minimize the influence of the magnetic field from the MFM tip on the magnetic domain structure during the magnetic force microscopy ( MFM ) measurements, NANOSENSORS™ PPP-LM-MFMR low moment magnetic AFM probes were used.* https://www.nanosensors.com/pointprobe-plus-magnetic-force…

These MFM probes are designed for magnetic force microscopy with reduced disturbance of the magnetic sample by the tip and enhanced lateral resolution compared to the standard PPP-MFMR probe. The distance between the tip and sample was maintained at a constant distance of 30 nm.*

Please have a look at the NANOSENSORS blog for the full citation and a direct link to the full article.

#multiferroics #spintronics #磁力显微镜 #AFMプローブ #SPM探针 #ScanningProbeMicroscopy

The Ultra-Short Cantilevers series https://www.nanoworld.com/ultra-short-cantilevers-afm-tips combines very small cantilevers capable of resonating in the MHz regime and a very sharp and wear resistant tip and is dedicated to High-Speed AFM (HS-AFM). The Ultra-Short Cantilevers series consists of six different types of probes which cover the complete range of high speed scanning applications, from non-contact mode to contact mode, from measurements in air to measurements in liquid.

More information such as high speed videos, an image gallery and a regularly updated reference list of scientific articles on high speed AFM can be found on the dedicated website: https://www.highspeedscanning.com/ . You can also find references to scientific articles mentioning the use of NanoWorld USC AFM probes on the NanoWorld blog.

If you haven’t seen the USC screencast yet have a look.

#高速AFMカンチレバー #highspeedAtomicForceMicroscopy #videorateAtomicForceMicroscopy #AtomicForceMicroscopy

In their study “Insights into dynamic sliding contacts from conductive atomic force microscopy” Nicholas Chan, Mohammad R. Vazirisereshk, Ashlie Martini and Philip Egberts used atomic force microscopy (AFM) to simultaneously acquire lattice resolution images of the lateral force and current flow through the tip–sample contact formed between a highly oriented pyrolytic graphite (HOPG) sample and a conductive diamond AFM probe to explore the underlying mechanisms and correlations between friction and conductivity. Both current and lateral force exhibited fluctuations corresponding to the periodicity of the HOPG lattice.

Unexpectedly, while lateral force increased during stick events of atomic stick-slip, the current decreased exponentially.*

The results presented in the study by Nicholas Chan et al. confirm that the correlation between conduction and atom–atom distance previously proposed for stationary contacts can be extended to sliding contacts in the stick-slip regime.*

A NANOSENSORS™ conductive diamond coated AFM probe CDT-CONTR was used to obtain all experimental data presented in their manuscript.* https://www.nanosensors.com/conductive-diamond-coated-tip…

Please have a look at the NANOSENSORS blog for the full citation and a direct link to the full article.

#HOPG #conductiveatomicforcmicroscopy #frictionforcemicroscopy #MaterialsResearch #AFMプローブ

The NANOSENSORS™ Membrane-type Surface-stress Sensor – MSS is a non-packaged MEMS sensor, a silicon membrane platform supported with four beams on which piezoresistors are embedded. It is mainly dedicated to R&D in the areas of olfactory sensing and electronic noses.

There are currently two major applications for this type of sensor:

-- the MSS has a great potential as a core component for electronic (artificial) nose systems / olfactory sensing systems utilized in e.g., medical, food, environment, safety and security fields.

-- the MSS can also be used for assessment of various materials like organic conductors, magnetic and superconductor materials in torque magnetometry.

To find out more please have a look at the video or at the NANOSENSORS™ MSS webpage https://www.mss-sensor.com/ or the NANOSENSORS™Special Developments List https://www.nanosensors.com/pdf/SpecialDevelopmentsList.pdf . On these pages you will not only get more information on which types of MSS Sensors are currently available but you will also find further information on the NANOSENSORS™ MSS 8 Channel Readout Module ( MSS-8RM ). The MSS-8RM is a basic electronic module to operate and to readout NANOSENSORS™ MSS that can be integrated in the researchers own set-up.

#ENose #NanomechanicalSensing #ArtificialNose #OlfactorySystem