A team of physicists has discovered how DNA molecules self-organize into
adhesive patches between particles in response to assembly instructions. Its
findings offer a "proof of concept" for an innovative way to produce
materials with a well-defined connectivity between the particles.
The work is reported in Proceedings of the National Academy of Sciences.
"We show that one can program particles to make tailored structures with
customized properties," explains Jasna Brujic, a professor in New York
University's Department of Physics and one of the researchers. "While
cranes, drills, and hammers must be controlled by humans in constructing
buildings, this work reveals how one can use physics to make smart materials
that 'know' how to assemble themselves."
Scientists have long sought a means for molecules to self-assemble and have
achieved breakthroughs on many fronts. However, less developed are measures
in which these tiny particles self-assemble with a preprogrammed number of
bonds.
To address this, Brujic and her colleagues, Angus McMullen, a postdoctoral
researcher in NYU's Department of Physics, and Sascha Hilgenfeldt, a
professor of mechanical science and engineering at the University of
Illinois, Urbana-Champaign, ran a series of experiments to capture—and
manipulate—the behavior of DNA molecules on particle surfaces.
Operating at a micron level—with particles 1/25th the size of a speck of
dust—they submerged tiny droplets into a liquid solution. Attached to these
droplets were "DNA linkers"—molecular tools possessing "sticky ends" that
allow for mixing and matching to form an array of structures desired by the
researchers.
"The beauty of this procedure is we can program the properties of a specific
material, such that it could be elastic or brittle, or even have
self-healing powers once broken, since the bonds can be made and broken
reversibly," observes Brujic. "Creators could decide to put in five
particles that stick to only one other one, 10 that stick to two, and 20
that stick to three, or any other combination. This would allow you to build
materials with specific topologies or architectures."
Reference:
DNA self-organization controls valence in programmable colloid design,
Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2112604118
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Physics