Nanoscience
Nanoscience Made EasyHarvard’s Kavli Institute for Bionano Science and Technology has its own idea of the cutting edge:
Tools for the non-expert.
THE ADVANCE of engineering at extremely small scales has led to
marvels of manufacturing, producing tiny transistors and circuits so
close-packed that palm-sized devices now have the computing power and
memory once held by room-sized machines. But two things this technology
is not: Simple and cheap. What Intel can manage, a typical biologist
cannot. Scientists studying the basic processes of life need equipment
of a different kind, not so sophisticated but much easier to use.
You could call it nanotechnology for the rest of us, and it is
central to the mission of the Kavli Institute for Bionano Science and
Technology (KIBST) at Harvard University. As the Institute’s
co-director, physicist David Weitz, explains, “We want to develop tools
that can be used by everybody -- particularly non-experts -- that
incorporate nanoscience and impact biology in a way that is
accessible.” Rather than simply advancing nanotech to smaller and
smaller scales, KIBST aims to make it practical for as many people as
possible.
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To show how flexible materials can be used to integrated microcircuits into fabrics, Adam Siegel and colleagues at Harvard University, including Kavli Institute co-director George Whitesides, invented a structure 200 micrometers wide capable of being tied into a knot. Depending on the solder compositions the wire can be solid or flexible, and any breaks can be healed by reheating it. (Credit: Adam C. Siegel and George Whitesides / Harvard)
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Making Cheaper, Simpler Technology
As an example, Weitz points to the work of KIBST’s other
co-director, George M. Whitesides, a Harvard professor of Chemistry and
Chemical Biology. Whitesides pioneered soft lithography, which makes
nanoscale structures by molding, etching or stamping with flexible
materials. This technology does not have the same precision as
traditional nanolithography used to make most semiconductors, but it is
cheaper and can do some things that conventional methods cannot, such
as creating structures on curved surfaces. (The most common
nanolithography method is to etch complex geometric patterns on flat
surfaces by shining light through a photomask).
Among other things, soft lithography does not require the completely
dust-free conditions needed to make semiconductors. “What I call a
‘dirty clean room’ is enough,” says Weitz, a Harvard professor of
Physics and Applied Physics whose research is focused on fluids, gels
and other soft materials and play key roles in cellular biology. This
is “a room where you keep it as clean as you can and you have all the
filters, but you don’t try to keep every last bit of dust out.” Soft
litho is faster, too. A microfluidics device, used for sorting cells,
can take two weeks to produce with traditional methods “if things
really go well,” says Weitz. At Harvard, soft lithography has reduced
the turnaround time to two days -- one day for printing a mask at a
West Coast facility and one day to express-ship the mask to Cambridge.
Since its introduction in the early-1990s, soft lithography has been
a boon to researchers in academia and industry. It’s not designed to
produce the next generation of microprocessors, but it’s ideal for
scientists who need tools for biological and medical research tasks,
such as identifying and isolating cancer cells. As such, it’s a model
for the research and technology development that Weitz and Whitesides
are now encouraging at KIBST, which was founded in 2006 and began its
recruiting and solicitation for project proposals in 2007. What they
look for are ideas that could affect biological research much as soft
litho has. They want research that has real-world impact – even
commercial success – whether or not it garners traditional academic
rewards such as prizes and published papers.
Looking for Promise and Potential
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Researchers led by David Weitz, co-director of the Kavli Institute for Bionano Science at Harvard University, have developed a “double bubble” method of delivering substances such as cancer drugs to locations where they would not survive without protection. A double-emulsion drop snaps off from a jet of two fluids within an outer fluid of viscous silicon oil. The middle fluid is water that contains a surfactant called sodium dodecyl sulfate, or SDS. The inner fluid is silicon oil. (Credit: Andrew Shinichi Utada / Harvard)
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Toward that end, they look for proposals that, in Whitesides’ words,
“don’t peer-review well” but promise potentially big payoffs. Weitz
explains: “What peer-reviews well is something that falls within the
traditional disciplines, is not very risky, has a clear, very
well-defined outcome and a high probability for success.” He and
Whitesides are willing to take chances on projects that may have a very
low probability for success but, if they work, “will be spectacular.”
The first round of proposals was solicited in 2007, and over twenty
proposals were received. Four inaugural grants of the KIBST were
awarded to six Harvard faculty. They include both experienced senior
faculty members as well as junior faculty just beginning their research
careers. A second round of proposals will be solicited in the coming
months.
The target of all this technology, including tools now in use as
well as those yet to be invented, is life at the molecular level. “Most
of what happens in biology happens at the scale of ten to 1,000
nanometers,” says Weitz. The mission of KIBST is to draw on the work of
Harvard researchers to illuminate the nanoscale realm where the
physical sciences and biological science meet. One example is the new
science of proteomics, the study of the proteins and their functions.
It’s a realm where disciplines meet. “Everything becomes structure,”
Weitz says, when life is observed at the nanometer scale and scientists
study “the chemical motors that drive biologic processes.” At this
interface of biology, chemistry and physics, KIBST is developing the
tools and techniques that can be used by scientists from all those
disciplines.
