Optical Nanoantennas Set the Stage for a NEMS Lab-on-a-Chip Revolution

D. Sikdar and M. Premaratne/Monash University Schematic representation of unidirectional cubic nanoantennas inducing directionality to omnidirectional nanoemitters (light sources, e.g., spasers, quantum dots), to precisely focus light with adjustable beam width and intensity, which can be tuned by adjusting the length of nanocube chain or intercube spacing. These ultra-narrow directional beams can play multiple roles in lab-on-a-chip devices such as illumination sources in microfluidic analysis or minute deflection registers in nanocantilever based sensors. All these signals are further detected in the photodetectors and get processed by on-chip signal processing circuitry for bio-molecular identification.

Newly developed tiny antennas, likened to spotlights on the nanoscale, offer the potential to measure food safety, identify pollutants in the air and even quickly diagnose and treat cancer, according to the Australian scientists who created them. The new antennas are cubic in shape. They do a better job than previous spherical ones at directing an ultra-narrow beam of light where it is needed, with little or no loss due to heating and scattering, they say.

In a paper published in the Journal of Applied Physics, from AIP Publishing, Debabrata Sikdar of Monash University in Victoria, Australia, and colleagues describe these and other envisioned applications for their nanocubes in “laboratories-on-a-chip.” The cubes, composed of insulating, rather than conducting or semiconducting materials as were the spherical versions, are easier to fabricate as well as more effective, he says.

Sikdar's paper presents analysis and simulation of 200-nanometer dielectric (nonconductive) nanoncubes placed in the path of visible and near-infrared light sources. The nanocubes are arranged in a chain, and the space between them can be adjusted to fine-tune the light beam as needed for various applications. As the separation between cubes increases, the angular width of the beam narrows and directionality improves, the researchers say.

“Unidirectional nanoantennas induce directionality to any omnidirectional light emitters like microlasers, nanolasers or spasers, and even quantum dots,” Sikdar said in an interview. Spasers are similar to lasers, but employ minute oscillations of electrons rather than light. Quantum dots are tiny crystals that produce specific colors, based on their size, and are widely used in color televisions. “Analogous to nanoscale spotlights, the cubic antennas focus light with precise control over direction and beam width,” he said.

The new cubic nanoantennas have the potential to revolutionize the infant field of nano-electromechanical systems (NEMS). “These unidirectional nanoantennas are most suitable for integrated optics-based biosensors to detect proteins, DNA, antibodies, enzymes, etc., in truly portable lab-on-a-chip platforms of the future,” Sikdar said. “They can also potentially replace the lossy on-chip IC (integrated circuit) interconnects, via transmitting optical signals within and among ICs, to ensure ultrafast data processing while minimizing device heating,” he added.

Sikdar and his colleagues plan to begin constructing unidirectional cubic NEMS antennas in the near future at the Melbourne Center for Nanofabrication. “We would like to collaborate with other research groups across the world, making all these wonders possible,” he said.

The article, “Optically Resonant Magneto-Electric Cubic Nanoantennas for Ultra-Directional Light Scattering,” is authored by Debabrata Sikdar, Wenlong Cheng and Malin Premaratne. It will be published in the Journal of Applied Physics on February 24, 2015 (DOI: 10.1063/1.4907536). After that date it can be accessed at: http://scitation.aip.org/content/aip/journal/jap/117/8/10.1063/1.4907536 

ABOUT THE JOURNAL

Journal of Applied Physics is an influential international journal publishing significant new experimental and theoretical results of applied physics research. See: http://jap.aip.org

Contact Information
Jason Socrates Bardi
American Institute of Physics
jbardi@aip.org

240-535-4954

@jasonbardi

Media Contact

Jason Socrates Bardi newswise

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors