Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


ORNL researchers probe chemistry, topography and mechanics with one instrument


The probe of an atomic force microscope (AFM) scans a surface to reveal details at a resolution 1,000 times greater than that of an optical microscope. That makes AFM the premier tool for analyzing physical features, but it cannot tell scientists anything about chemistry. For that they turn to the mass spectrometer (MS).

Now, scientists at the Department of Energy's Oak Ridge National Laboratory have combined these cornerstone capabilities into one instrument that can probe a sample in three dimensions and overlay information about the topography of its surface, the atomic-scale mechanical behavior near the surface, and the chemistry at and under the surface.

For a 500-nanometer-deep polymeric thin film made of polystyrene (lighter) and poly-2-vinylpyridine (darker), one multimodal instrument imaged, from left, surface topography, elasticity of the bulk material and buried chemical behavior.

Credit: Oak Ridge National Laboratory, US Dept. of Energy

This multimodal imaging will allow scientists to explore thin films of phase-separated polymers important for energy conversion and storage. Their results are published in ACS Nano, a journal of the American Chemical Society.

"Combining the two capabilities marries the best of both worlds," said project leader Olga Ovchinnikova, who co-led the study with Gary Van Berkel, head of ORNL's Organic and Biological Mass Spectrometry Group. "For the same location, you get not only precise location and physical characterization, but also precise chemical information."

Added Van Berkel, "This is the first time that we've shown that you can use multiple methods through the atomic force microscope. We demonstrated for the first time that you could collect diverse data sets together without changing probes and without changing the sample."

The new technique for functional imaging allows probing of regions on the order of billionths of meters, or nanometers, to characterize a sample's surface hills and valleys, its elasticity (or "bounciness") throughout deeper layers, and its chemical composition. Previously, AFM tips could penetrate only 20 nanometers to explore a substance's ability to expand and contract. Adding a thermal desorption probe to the mix allowed scientists to probe deeper, as the technique cooks matter off the surface and removes it as deep down as 140 nanometers. The MS's precise chemical analysis of compounds gave the new technique unprecedented ability to characterize samples.

"We're now able to see subsurface structure that we were blind to before, using standard techniques," Ovchinnikova said.

In the past, scientists measured physical and chemical properties on different instruments that displayed data on different resolution scales. The width of a pixel of AFM data might be 10 nanometers, whereas the width of a pixel of MS data might be 10 microns--a thousand times larger.

"The resolution of the chemical identification was much poorer," Ovchinnikova emphasized. "You would take images from different techniques and try to line them up and create a melded image. Because the pixel sizes would be so different, alignment would be difficult."

The ORNL innovation fixed that problem. "Because we are now using one setup, the pixel sizes are very similar to each other. You can pinpoint one pixel and correlate it to another pixel in the image," Ovchinnikova said. Now scientists can perfectly overlay data, much like digital cameras faultlessly stitch together smaller pictures to create a panoramic image.

Aligned analytics

It took a team to characterize the topographies, nanomechanics and chemistry of phase-separated domains and the interfaces between them. The scientists tested their combined AFM/MS platform by probing a phase-separated polymer thin film. Vera Bocharova, of the Soft Materials Group, made a 500-nanometer-thick film with polymers that separated into islands of poly-2-vinylpyridine in a sea of polystyrene. Vilmos Kertesz developed software to link analysis capabilities, and Van Berkel, Ovchinnikova and Tamin Tai set up the experiment and took and processed data. Mahmut Okatan, Alex Belianinov and Stephen Jesse of the Center for Nanophase Materials Sciences set up equipment to probe atom-scale mechanical properties.

Anasys Instruments, a developer of thermal probes, loaned the researchers a modified AFM instrument for the experiment. The company owns probe-tip intellectual property and licensed ORNL technology that uses heated AFM probes to remove matter from the surface and subsequently transport and ionize it for mass spectrometric analysis.

Anasys recently received a phase-2 Small Business Innovation Research grant from DOE to couple atomic force microscopy and mass spectrometry in a commercial product. Such a device would bring multimodal imaging out of the rarified realm of national labs and into the larger scientific community. Ovchinnikova envisions companies using the technology to answer fundamental questions about product performance. If a polymer blend--in a rubber tire or plastic bottle--is failing, why is it failing? In a stressed area, how are nanomechanical properties changing? What is the exact chemical composition at points of failure?

"This is something that AFM by itself could never see. It could just see differences in mechanics, but it could never really tell you precise chemistry in a location," said Ovchinnikova.

The ORNL researchers are eager to explore scientific challenges that could not be addressed before the advent of high-resolution chemical mapping. For example, a better understanding of the structure and properties of solar-energy materials may speed improvements in their efficiency.

Next, to make multimodal imaging even more powerful, the researchers are considering coupling thermal desorption mass spectrometry -- a destructive technique that cooks matter off a surface to enable its chemical analysis -- with optical spectroscopy, a nondestructive technique.


The title of the ORNL paper is "Co-registered Topographical, Band Excitation Nanomechanical, and Mass Spectral Imaging Using a Combined Atomic Force Microscopy/Mass Spectrometry Platform."

The research was sponsored by the US Department of Energy, Office of Science. A portion of the work was conducted at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility at ORNL.

UT-Battelle manages ORNL for DOE's Office of Science. The single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. -- by Dawn Levy


CAPTION/CREDIT: For a 500-nanometer-deep polymeric thin film made of polystyrene (lighter) and poly-2-vinylpyridine (darker), one multimodal instrument imaged, from left, surface topography, elasticity of the bulk material and buried chemical behavior. Image credit: Oak Ridge National Laboratory, US Dept. of Energy

NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at Additional information about ORNL is available at the sites below: Twitter - RSS Feeds - Flickr - YouTube - LinkedIn - Facebook

Dawn Levy | EurekAlert!

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>