Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electron tomography technique leads to 3-D reconstructions at the nanoscale

24.05.2018

A new transmission electron microscopy technique determines three-dimensional position of individual atoms

Understanding the microscopic structure of a material is key to understanding how it functions and its functional properties. Advances in fields like materials science have increasingly pushed abilities to determine these features to even higher resolutions.


This is a schematic of proposed TEM 3-D atomic imaging with multi-slice method with four examples of noisy intensity measurements at different angles of rotation, and 3-D atomic potential reconstructions and 1-D cross-sections along x and y directions.

Credit: David Ren

One technique for imaging at nanoscale resolution, transmission electron microscopy (TEM), is one example of promising technology in this area. Scientists recently found a way to harness the power of TEM to measure the structure of a material at the highest possible resolution - determining the 3D position of every individual atom.

Presenting their work at the OSA Imaging and Applied Optics Congress 25-28 June, in Orlando, Florida, USA, a team of researchers has demonstrated a technique using TEM tomography to determine the 3D positions of strongly scattering atoms.

... more about:
»3D »CT »Electron »OSA »Optical »algorithm »nanoscale »tomography

Through simulation, the group showed that it is possible to reconstruct the atomic potentials with atomic resolution using only image intensity measurements, and that it's possible to do so on molecules that are very sensitive to electron beams.

"Transmission electron microscopy is used extensively in both materials science and biology," said Colin Ophus, National Center for Electron Microscopy, Lawrence Berkeley National Lab, Berkeley, California, and a member of the research team.

"Because we fully solve the nonlinear propagation of the electron beam, our tomographic reconstruction method will enable more quantitative reconstruction of weakly scattering samples, at higher or even atomic resolution."

Similar to the way computerized tomography (CT) scans performed for medical imaging in hospitals are built using a series of two-dimensional cross-sectional images at different increments, electron tomography constructs a three-dimensional volume by rotating samples incrementally, collecting two-dimensional images.

While most CT imaging in hospitals is done with x-rays to determine features of larger things like bones, the beams of electrons used in TEM allows researchers to look with significantly higher resolution, down to the atomic scale.

"However, on the atomic scale we cannot neglect the very complex quantum mechanical effects of the sample on the electron beam," Ophus said. "This means in our work, we must use a much more sophisticated algorithm to recover the atomic structure than those used in an MRI or CT scan."

The TEM setup the group used measured the energy intensity that hits the microscope's sensor, which is proportional to the number of electrons that hit the sensor, a number that depends on how the electron beam is configured for each experiment. Using the intensity data, the new algorithm designed by the group stitched the two-dimensional projected images into a 3D volume.

Making the jump to three dimensions with large fields of view, however, can tax computers exponentially more than dealing with single 2D images. To work around this, they modified their algorithm to be used on graphic processing units (GPUs), which can perform many times more mathematical operations in parallel than typical computer processing units (CPUs).

"We are able to obtain results in a reasonable amount of time for realistic sample dimensions," said David Ren, a member of the team.

With generally weaker bonds between their atoms, biomolecules can be notoriously difficult to study using TEM because the electron beams used to study a metal alloy, for example, would typically tear a biomolecule apart. Lowering the electron dosage in a sample, though, can create images that are so noisy, other algorithms currently in use can't reconstruct a 3D image. Thanks to a more precise physical model, the team's new algorithm has the ability.

Now that they have fully developed the reconstruction algorithm, the team said they hope to apply what they've observed from simulations to experimental data. They plan to make all of their reconstruction codes available as open source for the wider research community.

###

Hear from the research team: MM2D.3. "Tomographic reconstruction of 3D atomic potentials from intensity-only TEM measurements," by the research team from the National Center for Electron Microscopy, Lawrence Berkeley National Lab, Berkeley, California; David Ren; Michael Chen; Colin Ophus; Laura Waller at 11:15 am on 25 June 2018, at the Wyndham Orlando Resort International Drive, Orlando, Florida, United States.

MEDIA REGISTRATION: Media/analyst registration for the OSA Imaging and Applied Optics Conference 2018 can be accessed online. Further information is available on the event website, including travel details.

ABOUT OSA IMAGING AND APPLIED OPTICS CONGRESS

Imaging and Applied Optics Congress provides a comprehensive view of the latest developments in imaging and applied optical sciences, covering the forefront advances in imaging and applied optics as well as the application of these technologies to important industrial, military and medical challenges. The scope of the research presented in ranges from fundamental research to applied. General Chair for the 2018 Congress is Gisele Bennett, Florida Institute of Technology, USA.

Media Contacts:

Rebecca B. Andersen
The Optical Society
+1 202.416.1443
RAndersen@osa.org

Azalea Coste
The Optical Society
+1.202.416.1435
ACoste@osa.org

Media Contact

Rebecca Andersen
randersen@osa.org
202-416-1443

 @opticalsociety

http://www.osa.org 

Rebecca Andersen | EurekAlert!
Further information:
https://www.osa.org/en-us/about_osa/newsroom/news_releases/2018/electron_tomography_technique_leads_to_3d_reconstr/

Further reports about: 3D CT Electron OSA Optical algorithm nanoscale tomography

More articles from Materials Sciences:

nachricht Breakthrough in nanoresearch - Quantum chains in graphene nanoribbons
09.08.2018 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

nachricht UNH Researchers find seed coats could lead to strong, tough, yet flexible materials
08.08.2018 | University of New Hampshire

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

Im Focus: A molecular switch may serve as new target point for cancer and diabetes therapies

If certain signaling cascades are misregulated, diseases like cancer, obesity and diabetes may occur. A mechanism recently discovered by scientists at the Leibniz- Forschungsinstitut für Molekulare Pharmakologie (FMP) in Berlin and at the University of Geneva has a crucial influence on such signaling cascades and may be an important key for the future development of therapies against these diseases. The results of the study have just been published in the prestigious scientific journal 'Molecular Cell'.

Cell growth and cell differentiation as well as the release and efficacy of hormones such as insulin depend on the presence of lipids. Lipids are small...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Can radar replace stethoscopes?

14.08.2018 | Medical Engineering

The end-Cretaceous extinction unleashed modern shark diversity

14.08.2018 | Life Sciences

Light-controlled molecules: Scientists develop new recycling strategy

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>