August
22, 2005 --- Scientists at Columbia University's
Nanoscience Center have solved a fundamental, and
to date, highly elusive challenge in the fast-developing
world of nanotech-molecular electronic devices.
In the July 22nd issue of Science , Colin Nuckolls, an associate professor
of chemistry, and his colleagues George Tulevski, Matt Myers, Michael Steigerwald,
along with Mark S. Hybertsen, from the department of applied physics and applied
mathematics, describe how they created a so-called electricity-bridge to allow
current to flow efficiently between molecules and nano-sized metals, a process
necessary for molecular electronic device construction.
The discovery -- involving the ability to construct materials or machines on
nano-scales (a nanometer is a billionth of a meter) -- brings scientists
one step closer to achieving previously unimagined possibilities, including
information processing with molecules, medicines from nanoparticles that vastly
improve delivery and dosage, and molecule-sized robots that flow through a
person's bloodstream to treat clogged arteries in heart attack or (potential
heart attack) patients.
Nuckolls' research team at Columbia's Nanoscience Center built an effective
bridge linking the molecular world with a metal (Ruthenium) that is conductive,
stable and durable. The majority of experiments to date have used gold as a
possible link, which does not offer good electrical conductivity, lacks endurance
and doesn't have any useful subsequent chemistry.
Successful miniaturization (i.e., building nanoscale devices) requires these "electricity-bridges" since
most electrical activity that is important in electronic devices occurs within
just a few nanometers of an interface. "It can not be overstated how important
these interfacial structures and properties are," Nuckolls says. "In a sense,
interfaces are where the 'expanding nano' of chemistry and the 'shrinking nano'
of electronics meet." In other words, he adds, "interfaces are where the rubber
meets the road."
Nuckolls' research exemplifies Columbia's interdisciplinary approach and the
University's effort to coordinate and harness expertise in various fields --
in this case, engineering, chemistry, mathematics, biology and numerous others
to address emerging 21 st century scientific challenges.
Founded in 2001, Columbia's Nanoscience Center draws upon years of experience
in chemical synthesis to design molecular structures with carefully crafted
properties. Its work has the potential to impact major disciplines in addition
to electronics including photonics, biology, neuroscience and medicine. For
more information, please visit the Nanoscience
Center .
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