Nanoantenna

A nanoantenna is a device that absorbs small wavelength electromagnetic radiation through resonance.

Microscopy

Nanoantennas help to focus light more than is possible with convention materials. Metallic nanostructures may be able to eventually detect single molecules. [ [http://www.purdue.edu/UNS/html4ever/020821.Shalaev.nanoantenna.html 'Nanoantennas' could bring sensitive detectors, optical circuits] Purdue News. August 21, 2002]

Bowtie Nanoantenna

The bowtie nanoantenna is a structure that is on the order of hundreds of nanometers that can compress light into a region up to 20 nanometers in diameter. [ [http://news-service.stanford.edu/news/2005/september14/bowtie-091405.html 'Bowtie nanoantennas' could shed light on molecules, other nano-sized objects] ] The device consists of two triangular pieces of metal, often Gold, with the tips facing each other. By varying the geometeries of the antenna the intensity of various wavelengths of light can be enhanced.

Chirality - Super Lens

Most materials, including air, water, and plastic, are termed "right-handed" with regard to how light bends when it penetrates the material. Light bends in the opposite direction when it penetrates "left-handed" materials. The nanoantenna is a left-handed type of material that could be used to create a super lens, which helps improve the resolution of medical diagnostic images.

Integration to Create Devices

Plasmonic Laser Nanoantenna

Engineers and scientists demonstrated a plasmonic laser nanoantenna, created by integrating a metallic nanostructure with a commercial semiconductor laser. [" [http://www.eurekalert.org/pub_releases/2006-09/hu-hue090606.php Harvard University engineers demonstrate laser nanoantenna] " Public Release Date: September 6, 2006. Contact: Michael Rutter] The optical antenna is able to collect and focus light within a region of tens of nanometers. The opitcal antenna operates within the visible and infrared portion of the electromagnetic spectrum. It is believed that using this tool with optical storage platforms could result in memory capacities of terabytes.

olar Nanoantennas

The technology of solar arrays of nanoantennas is expected to be highly efficient with regard to capturing energy (80% efficiency) and in the process of creating the device (cents per yard). [ [http://www.triplepundit.com/pages/nanoantennas-solar-arrays-that-002905.php Nanoantennas: Solar arrays that absorb energy even in the dark!!] February 11, 2008] Small square spirals of metal can be printed on plastic sheets. The antennas can capture energy associated with infrared radiation, which reaches the earth from the sun during the day and is emitted by the earth at night.

U.S. DOE's Idaho National Laboratory (INL) has developed a method of producing plastic sheets that contain billions of nanoantennas to convert the sun's infrared rays into electricity. The nanoantennas consist of tiny gold squares or spirals set in a specially treated layer of polyethylene, a common plastic. While the device is not yet practical, it has the potential to run off either sunlight or waste heat [ [https://inlportal.inl.gov/portal/server.pt?open=514&objID=1555&mode=2&featurestory=DA_144483 Harvesting the sun's energy with antennas] ] .

Engineers at the University of California, San Diego (UCSD) have employed similar "nanowires" to boost the efficiency of organic solar cells, which are made of plastic [http://ucsdnews.ucsd.edu/newsrel/science/05-08Nanowires.asp] .

Computers

Scientists hope to create computers that use photons instead of electrons to transmit signals. [ [http://www.purdue.edu/UNS/html4ever/020821.Shalaev.nanoantenna.html 'Nanoantennas' could bring sensitive detectors, optical circuits] Purdue News. August 21, 2002] Manipulating photons is more difficult than electrons since they do not carry charge. It's theoretically possible to simulate all the properties of electric circuits with plasmonic nanomaterials used to guide light.

Future Prospects

Biological Probes

Ken Crozier, a professor at Harvard University, envisions laser antennas being integrated with new biological probes, such as optical tweezers. [" [http://www.eurekalert.org/pub_releases/2006-09/hu-hue090606.php Harvard University engineers demonstrate laser nanoantenna] Public Release Date: September 6, 2006. Contact: Michael Rutter]

Modeling Behavior of Nanoantennas

Steven Novack, a physicist at the Idaho National Laboratory, believes modeling the behavior of nanoantennas can help optimize their performance. [ [http://www.triplepundit.com/pages/nanoantennas-solar-arrays-that-002905.php Nanoantennas: Solar arrays that absorb energy even in the dark!!] February 11, 2008]

References