Insights into dynamic sliding contacts from conductive atomic force microscopy

Friction in nanoscale contacts is determined by the size and structure of the interface that is hidden between the contacting bodies. One approach to investigating the origins of friction is to measure electrical conductivity as a proxy for contact size and structure. However, the relationships between contact, friction and conductivity are not fully understood, limiting the usefulness of such measurements for interpreting dynamic sliding properties.*

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.*

Figure 1 (a) from “Insights into dynamic sliding contacts from conductive atomic force microscopy” by Nicholas Chan et al:
A schematic of the experimental setup is shown in Fig. 1(a). The experiment was conducted using an ultra-high vacuum (UHV) (RHK) AFM at room temperature at a pressure of <1109Torr. A doped diamond coated cantilever (NANOSENSORS CDT-CONTR) with a normal bending spring constant of 0.86 N m1and lateral spring constant of 10 N m1was used to obtain all experimental data presented in this manuscript.

Figure 1 (a) from “Insights into dynamic sliding contacts from conductive atomic force microscopy” by Nicholas Chan et al:
A schematic of the experimental setup is shown in Fig. 1(a). The experiment was conducted using an ultra-high vacuum (UHV)AFM at room temperature at a pressure of <1109Torr. A doped diamond coated cantilever (NANOSENSORS CDT-CONTR) with a normal bending spring constant of 0.86 N m1and lateral spring constant of 10 N m1was used to obtain all experimental data presented in this manuscript.

*Nicholas Chan, Mohammad R. Vazirisereshk, Ashlie Martini and Philip Egberts
Insights into dynamic sliding contacts from conductive atomic force microscopy
Nanoscale Advances., 2020, Advance Article
DOI: 10.1039/d0na00414f

Please follow this external link to read the whole article: https://pubs.rsc.org/en/content/articlepdf/2020/na/d0na00414f

Open Access: The article “Insights into dynamic sliding contacts from conductive atomic force microscopy” by Nicholas Chan, Mohammad R. Vazirisereshk, Ashlie Martini and Philip Egberts is licensed under a Creative Commons Attribution 3.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/.

Video on NANOSENSORS™ Membrane-type Surface-stress Sensors (MSS) for olfactory sensing passes 1500 views mark

The video on NANOSENSORS™ Membrane-type Surface-stress Sensors (MSS) for olfactory sensing has passed the 1500 views mark. Thank you all for watching.

Video: What are NANOSENSORS Membrane-type Surface-stress Sensors (MSS) for R&D in gas/odor sensing?

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 or the NANOSENSORS™Special Developments List. 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.

Soft, drift-reduced AFM cantilevers for Biology and Life Sciences – Uniqprobe Screencast passes the 1000 views mark

The screencast on the soft, drift-reduced NANOSENSORS™ uniqprobe cantilevers for biology and life science applications held by Dr. Laure Aeschimann has just passed the 1000 views mark. Congratulations Laure!

Since the first publication of this screencast that presents the uniqprobe types qp-BioAC, qp-BioT, qp-SCONT and qp-CONT , three further types of uniqprobe AFM probes have been introduced:

qp-BioAC-CI – a version of uniqprobe™ BioAC with Rounded Tips for Cell Imaging

qp-fast – three different uniqprobe™ cantilevers on one support chip for Soft- , Standard- , Fast Tapping/Dynamic AFM Imaging

and qp-HBC – the uniqprobe™ – HeartBeatCantilever that can also be used for ScanAsyst** and Peak Force Tapping** in Air.

To find out more please have a look at the NANOSENSORS™ uniqprobe brochure or the individual product pages on the NANOSENSORS webpage.

Additionally we have also put tipless versions of the qp-SCONT, qp-CONT and the qp-BioT ( SD-qp-BioT-TL, SD-qp-CONT-TL, SD-qp-SCONT-TL) and uniqprobe tipless cantilever arrays ( SD-qp-TL8a and SD-qp-TL8b ) on the NANOSENSORS special developments list.

Feel free to browse or let us know if you have any questions via info(at)nanosensors.com.

Product Screencast on the NANOSENSORS™ uniqprobe AFM Probes series with unsurpassed small variation in spring constant and resonance frequency by product developer Dr. Laure Aeschimann

A Japaneseversion of the screencast is also available :

バイオテクノロジー/ライフサイエンス向け NANOSENSORS ユニーク·プローブ Uniqprobe

A Chinese version of the Uniqprobe screencast is available on three different channels:

NANOSENSORS公司的吴烨娴博士在本视频中介绍了Uniqprobe原子力显微镜探针。Uniqprobe 探针 的悬臂梁厚度均一,并且有局部的金反射涂层。这两个特点使得这个探针在一些对弹性系数有精确要求的应用中, 表现出卓越的机械性能一致性 。该探针特别适用于分子生物学,生物物理学和定量纳米机械的研究.

The Chinese version is also available on Youku: http://v.youku.com/v_show/id_XNzA4MTgxNTI4.html
or weibo http://weibo.com/u/5077581192?is_all=1

** ScanAsyst® and PeakForce Tapping™ are trademarks of Bruker Corp.