The printing press is one of the most important inventions
of our age. Although many are moving closer toward digital rather than printed
medium, some researchers are finding
ways to carry the printing concept to a new level.
Researchers from IBM and ETH Zurich have demonstrated a new technique
to “print” at the nanoscale, yielding the world’s current smallest piece of
art. Rather than just lending the technology to legal departments to write even
smaller tinyprint, the more important application of this invention could apply
to nanoscale production.
“In traditional gravure printing, a doctor blade is used to
fill the recessed features of a printing plate with ink, in which pigment
particles are randomly dispersed,” explains Tobias Kraus, of the nanopatterning
team in Zurich. “In our high-resolution printing, a directed self-assembly
process controls the arrangement of nanoparticles on the printing plate or
template. The entire assembly is then printed onto a target surface, whereby
the particle positions are precisely retained at a resolution that is three
orders of magnitude higher than in conventional printing.”
Current, standard methods of top-down micro-fabrication
involve carving particles out of a larger material. The new printing process
differs by adding ready-made nanoparticles onto a surface and allows for
different types of materials such as metals, polymers, semiconductors, and
oxides to be combined in one process.
Using the printing process, researchers were able to
demonstrate particles as tiny as 60nm, reaching a translated resolution of
100,000 dpi.
The new method by IBM and ETH Zurich could be applied to printing
of large arrays of biofunctional beads that can detect and identify certain
cells or markers in the body, such as cancer cells or heart attack markers.
The printed nanoparticles can also interact with light,
creating a use in optoelectronic devices like optical chips. For future semiconductor
use, the printing process could aid placement of catalytic seed particles for
growing semiconducting nanowires.
“This method opens up new ways to precisely and efficiently
position various kinds of nanoparticles on different surfaces, a prerequisite
for exploiting the unique properties of such nanoparticles and for making their
use economically feasible,” explains Heiko Wolf, researcher in nanopatterning
at IBM’s Zurich Research lab.
