RHK talk to Prof. Rob Carpick, professor of Mechanical Engineering at the University of Pennsylvania and a long time RHK microscope and controller user, about the new R9 controller that is being used in their lab.
RHK: Please can you provide our readers with an overview of the type of research you are conducting?
RC: We do a lot of work in contact mode, atomic force microscopy for nanotribology research. We are studying friction, adhesion, and wear properties at the nanoscale using scanning probes. We also do contact mode, tapping mode, frequency modulation, imaging of surfaces for high-resolution topographic measurements; so we do both mechanical measurements and imaging measurements.
RHK: You have used the SPM 100 for a number of years and now you have the R9 controller. What types of measurements are you hoping to enable with the new technology?
RC: One thing that we do quite often, because we're measuring things like friction and adhesion, is use customized scanning modes. So we might be ramping the load or taking intermittent force curves while imaging. Many of these capabilities were possible with the existing software, but now it's much more flexible, customizable, and integrated, in a way that lets us perform a whole range of unusual and customized data acquisition modes.
Another area we are working on with RHK is a high-speed data acquisition method, where both the bandwidth and flexibility electronics allow us to use a custom sample holder that we've designed to do high-speed scanning while shearing a sample at a high rate.
We're trying to look at the dependence of friction on velocity and this allows us to access higher velocities. Previously we had to have an external module. Now we're going to be able to integrate everything into the R9 electronics through the customizable programming interface.
RHK: Are you writing your own IHL or IHDL files, or are you implementing third party scripts like Labview scripts into R9 to execute?
RC: Previously we had been using Labview with an external module and now we're expecting to be able to integrate that by working with RHK to provide specialist input. This will allow us to take what we have already developed and import it. This flexibility is really beneficial to us.
RHK: Have you been working with the RHK support team on this?
RC: Yes, they've been very helpful. We call them all of the time. We've received a lot of support and feedback on these often very unusual customized modes that come up all of the time in research. Another thing that we are looking at a lot more recently is frequency modulation imaging. Using R9, integrated in a way that is much more convenient, rapid and customizable than before. An almost push button like operation for frequency modulation is certainly a very nice advance for the system. We have already benefited from that capability.
RHK: How long have you been using R9 now?
RC: We first started testing it out about 5 or 6 months ago. We are still at the early stages, but something that we observed right away was that there was a significant improvement in the signal to noise. We take friction images all of the time and these can be looking at very small scans that are just a couple nanometer scan sizes. This means you're really subject to limits that show up from any noise source including electronic. We saw that there was a significant improvement in the noise level and a significant improvement in bandwidth as well.
The students have been taking it for a test drive and they have insisted that they wanted to stick with it as they were getting better data.
R9: A Fully Integrated Solution
The unique R9 from RHK Technology has been developed based on nearly 25 years of technological expertise in scanning probe microscopy. The R9 offers a highly integrated control system for all SPM modes and processes such as STM, STS mapping, STS, force-distance, contact, intermittent contact, qPlus, EFM, MFM, C-AFM and KFM.
Well-designed software handles all connections between modes, removing the use of multiple signal-degrading cables.
The R9 offers all of the components needed for measurement modes, including the most advanced, such as lock-in amplifiers, pulse generators and signal generators, high voltage amplifiers, PLLs, digital filters, and additional feedback loops.
- Can work with any SPM
- Excellent signal quality is provided by the all digital, purpose-built hardware
- Time-based data acquisition with all parameter changes recorded in real-time
- One-box integration for complete AFM, STM and even KFM control
- Fast transient measurement: 10 ns
- RHK’s patented IHDL™ for easy, drag-and-drop setup of parts that automatically connect and validate
- Patented, completely synced, lock-ins and PLLs
- Analog bandwidth of 20MHz for high frequency/harmonics detection
- Lightning-fast crash proof tip-sample approach
About Prof. Rob Carpick
Robert W. Carpick is the John Henry Towne Professor and Department Chair in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania. He holds a secondary appointment in the Department of Materials Science and Engineering, and is a member of the Physics Graduate Group. Prof. Carpick moved to U. Penn in January 2007 after serving on the faculty for 7 years in the Engineering Physics Department at the University of Wisconsin-Madison.
Prof. Carpick received his B.Sc. in Physics from the University of Toronto in 1991, and his M.A. and Ph.D. in Physics from the University of California at Berkeley in 1997 under the supervision of Dr. Miquel Salmeron. His thesis is titled: “The Study of Contact, Adhesion and Friction at the Atomic Scale by Atomic Force Microscopy”.
He spent two years as a postdoctoral appointee at Sandia National Laboratory in the Surface and Interface Science Department, and then the Biomolecular Materials and Interfaces Department where he worked under the supervision of Dr. Alan R. Burns.
Prof. Carpick works at the intersection of mechanics, materials, and physics to conduct research into nanotribology (the atomic-scale origins of friction, adhesion, lubrication, and wear), nanomechanics, nanostructured materials, surface science, and scanning probe microscopy (SPM) including in situ methods. His primary focus is on using SPM and other surface science and material characterization techniques to probe the fundamental nature of materials in contact, and to apply the results to nanotechnology applications. Recently he has focused extensively on the science and technology of ultrahard carbon-based thin films including nanocrystalline diamond, ultrathin materials such as graphene, and materials under extreme conditions.
Prof. Carpick was named a Fellow of the American Physical Society in 2012, and a Fellow of the American Vacuum Society in 2014. He currently serves on the Editorial Boards of the journals Tribology Letters and Advanced Materials Interfaces, and served as a Board Member of the Solid Lubricants Division of the Society of Tribologists and Lubrication Engineers (2004-2009), serving as Division Chair for 2008-2009. He previously served as an elected board member of the Nanoscale Science and Technology Division of the American Vacuum Society, and on the Editorial Board of Review of Scientific Instruments. He was the recipient of a CAREER Award from the National Science Foundation in 2001, and was named Outstanding New Mechanics Educator by the American Society for Engineering Education in 2003. In 2009, he was awarded the Burt L. Newkirk Award of the American Society of Mechanical Engineers. He is a co-recipient of a R&D 100 Award for the co-development of ultrananocrystalline diamond AFM probes, sold commercially as “NaDia Probes” by Advanced Diamond Technologies, Inc. He has taught several invited short courses on nanomechanics and scanning probe microscopy, is the author of over 130 peer-reviewed publications, and holds 3 issued patents.
From 2007-2011, Prof. Carpick served as the University of Pennsylvania Director of the Nanotechnology Institute (NTI), a multi-institutional entity funded by the Commonwealth of Pennsylvania that supports the commercialization of nanotechnology by funding university-based translational research with industrial collaboration.
This information has been sourced, reviewed and adapted from materials provided by RHK Technology.
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