Researchers at the University of Illinois at Urbana-Champaign have demonstrated that an array of novel gold, pillar-bowtie nanoantennas (pBNAs) can be used like traditional photographic film to record light for distances that are much smaller than the wavelength of light (for example, distances less than ~600 nm for red light). A standard optical microscope acts as a "nanocamera" whereas the pBNAs are the analogous film.
"Unlike conventional photographic film, the effect (writing and curing) is seen in real time," explained Kimani Toussaint, an associate professor of mechanical science and engineering, who led the research. "We have demonstrated that this multifunctional plasmonic film can be used to create optofluidic channels without walls. Because simple diode lasers and low-input power densities are sufficient to record near-field optical information in the pBNAs, this increases the potential for optical data storage applications using off-the-shelf, low-cost, read-write laser systems."
"Particle manipulation is the proof-of-principle application," stated Brian Roxworthy, first author of the group's paper, "Multifunctional Plasmonic Film for Recording Near-Field Optical Intensity," published in the journal, Nano Letters.
"Specifically, the trajectory of trapped particles in solution is controlled by the pattern written into the pBNAs. This is equivalent to creating channels on the surface for particle guiding except that these channels do not have physical walls (in contrast to those optofluidics systems where physical channels are fabricated in materials such as PDMS)."
To prove their findings, the team demonstrated various written patternsincluding the University's "Block I" logo and brief animation of a stick figure walkingthat were either holographically transferred to the pBNAs or laser-written using steering mirrors.
|Contact: Kimani Toussaint|
University of Illinois College of Engineering