Researchers have shown how tiny wires and metallic spheres might be arranged in various shapes to form "nanoantennas" that dramatically increase the precision of medical diagnostic imaging and devices that detect chemical and biological warfare agents.
Engineers from Purdue University have demonstrated through mathematical simulations that nanometer-scale antennas with certain geometric shapes should be able to make possible new sensors capable of detecting a single molecule of a chemical or biological agent. Such an innovation could result in detectors that are, in some cases, millions of times more sensitive than current technology.
The nanoantennas in the simulations are made of metal wires and spheres only about 10 nanometers thick -- or roughly 100 atoms wide. The Purdue researchers are the first to show precisely how the nanoantennas could be applied to visible light and other electromagnetic radiation consisting of short wavelengths. Scientists at the University of California at San Diego proved two years ago that the nanoantennas could be applied to devices that use microwaves, which are much longer than the waves needed for medical imaging, and for sensors used in spectroscopy to detect chemicals and biological agents. The phenomenon was first predicted in the late 1960s.