The next frontier for information processing may lie at the interface
of nanoelectronics and biotechnology.
An interdisciplinary team
led by electrical and computer engineering professor Richard
Kiehl is exploring the use of DNA as a programmable scaffolding
for the
self-assembly of nanoscale electronic components. As a model
for fabricating and designing semiconductor devices and circuits,
DNA
offers two key advantages: size scale and programmability.
Most industry experts believe that within the next
10 to 15 years the ability to scale down conventional
technologies will reach its limit. At that point, the
operating principles of conventional devices—and
the techniques used to fabricate them—will break
down. The basic elements of the DNA molecule are at
just the right scale, says Kiehl.
Self-assembly uses bio-recognition, a natural process in which
one molecule is attracted to and binds with another to form small
structures. In the case of DNA, the attraction can be programmed
so that the molecules will spontaneously assemble in solution to
achieve a desired result.
“It's possible to synthesize small versions of DNA molecules in
the laboratory and program in whatever code you want,” says Kiehl.
“And because the two strands of DNA have complementary codes that
match up, you can design one strand of DNA in a certain way so it
will match another strand and assemble a nanoscale structure this
way."
The matched segments form a scaffolding on which nanoparticles
are affixed at highly selective attachment points. It's an approach
that offers the programmability and precision needed for assembling
electronic circuitry on the nanoscale.
“We have to make a real paradigm shift,” Kiehl says. “Not only
do we have to keep improving performance, but we also must look
at the kinds of devices we can make at those scales and how we want
to use them to process information."
To that end, the researchers are turning to the human brain for
inspiration. They envision devices whose electrical characteristics
resemble those of neuron-like electrical waveforms in the brain.
Like certain regions of the brain, the devices would process information
based on pattern recognition rather than on individual bits of information.
It's a more sophisticated level of information processing than can
be achieved using conventional computers.
Kiehl predicts there will be a wide range of applications for
this technology, including signal processing, communications systems,
and computer systems. “The higher end of this [work] will be things
that computers can't do very well today because the operations they
use are too restrictive. One is the ability to recognize a pattern,
such as identifying a letter as being an 'A' or a 'B', or being
able to identify a face.
“It won't be just making things faster and faster in the conventional
way,” he says. “It will really be opening up new ways to process
information in machines."
