An innovation that can help scientists observe a reaction moving at greater
than 10 meters per second, with a few nanometers spatial resolution, is a feat
some would say is nearly impossible.
But not the Lawrence Livermore
team of scientists who developed the dynamic transmission electron microscope
(DTEM).
Working with the dynamic transmission electron microscope (DTEM). From left: Bryan Reed, Melissa Santala, William DeHope, Thomas LaGrange, Joseph McKeown. Photo by Jacqueline McBride/LLNL
DTEM’s ability to let researchers peer into the heart of scientific
phenomena while it’s happening has earned it one of the 10 winning microscopy
innovations in the 2010 Microscopy Today Innovation Award competition.
Microscopy Today's MT-10 Awards recognize the best new products and methods
across the entire field of microscopy. Five of the awards are primarily related
to the life sciences and five are related to the physical sciences. In each
of these areas, there may be interesting new developments in light microscopy,
scanning probe microscopy, electron microscopy, ion microscopy, acoustic microscopy,
microanalysis, specimen preparation, etc. These awards honor the best developments
in microscopy from the previous calendar year.
The award will be given to the team at the 2010 Microscopy & Microanalysis
meeting held Aug. 1-5 in Portland, Ore. Descriptions of the winning products
and methods will be published in the print and digital editions of the September
2010 issue of Microscopy Today.
Unlike traditional transmission electron microscopes that are generally restricted
to capturing images before and after some rapid transformation (such as a material
deforming or the growth of a nanowire), the DTEM captures images during the
process itself. DTEM goes beyond merely revealing that a transformation has
happened; it provides crucial details of how, when and where it happened. For
example, while a conventional electron microscope can produce static images
of viruses before and after they have attacked cells, the DTEM could potentially
capture a virus in the process of joining to a membrane and releasing its genetic
material in a rapid sequence of short-exposure images.
The DTEM is able to take snapshots of the dynamics that occur in samples of
material under strenuous conditions – extreme temperature, applied pressure,
surface corrosion – creating a visual record of microstructural features
as they rapidly evolve.
It combines all of the powerful techniques of the standard TEM with nanosecond
time resolution for capturing dynamic processes while they occur with single-shot
measurements. (The term “single shot” means the gathering of the
required data, diffraction pattern or image, using only one bunch of electrons.)
The Livermore microscope already has produced new levels of scientific understanding
of nanostructure growth, phase transformations and chemical reactions. But this
is only the beginning.
DTEM provides an entirely new way of exploring material processes with a range
of potential applications that have just been undertaken.
In a recent experiment, the team was able to peer into the inner workings of
catalyst nanoparticles 3,000 times smaller than a human hair within nanoseconds.
The findings point the way toward future work that could greatly improve catalyst
efficiency in a variety of processes that are crucial to the world’s energy
security, such as petroleum catalysis and catalyst-based nanomaterial growth
for next-generation rechargeable batteries.
The research is funded by the Department of Energy’s Office of Science,
Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.
Members of the team include: Wayne King, Michael Armstrong, Nigel Browning,
Geoffrey Campbell, William DeHope, Judy Kim, Thomas LaGrange, Benjamin Pyke,
Bryan Reed, Richard Shuttlesworth, Brent Stuart and former LLNL employees J.
Bradley Pesavento Mitra Taheri and Benjamin Torralva.