There was a time when the laws of physics bound the possible. After all, the physical world, from living tissue to digital networks that carry our information and communications around the world, is based on atoms that define how these things behave. There are upper limits on performance, actions and reactions. But what if we could essentially redefine the atom to create next generation devices that are highly tuned to behave in very specific ways? Doing this could have groundbreaking impacts in security, communications, health and safety.
It’s happening right now.
Nanostructures are the New Atoms
It all starts with metamaterials (from the Greek word µετά meta, meaning “beyond”), which are materials engineered to have properties not found in nature. We make metamaterials by assembling multiple elements made from composite materials such as metals or dielectrics (materials that are poor conductors of electricity, but efficient supporters of electrostatic fields). They are usually arranged in repeating patterns, at scales that are smaller than the wavelengths of the phenomena they influence.
While natural materials have properties based on their elements (for example, metal-based materials are strong, but heavy and have high loss), metamaterials have properties based on these repeating patterns, and their exact shape, geometry, size, orientation and arrangement gives them their smart properties capable of manipulating electromagnetic waves. 1 By arranging metamaterials in specific ways at infrared and visible wavelengths, scientists create nanostructures, which are essentially sequences of man-made atoms.
That’s what Marconi Society Paul Baran Young Scholar Salvatore Campione is working on as a Senior Member of Technical Staff at Sandia National Laboratories. This work recently led the IEEE Eta Kappa Nu Honor Society to name him as the Society’s 2016 Outstanding Young Professional.
From Communications to Healthcare
Nanostructures are used to create devices that can be engineered and designed to solve a variety of problems. Here are just a few:
As our world becomes more connected and the number of people and devices on the network grows exponentially, moving information quickly, cheaply and effectively becomes more important than ever. While an ever-increasing portion of our networks is moving to the optical communication wavelength of 1.55 micrometers, thanks to optical fibers, there are many devices, such as filters, modulators and multiplexers that do not offer the speed and performance we need. Optoelectronics is a branch of research working to optimize these bottleneck devices for fiber speeds and performance.
Researchers in optoelectronics, such as Salvatore Campione, are investigating metamaterials to be used as filters and modulators to enhance network’s performance across all devices. While metamaterials and nanostructures allow researchers to create any type of filter, once these filters are tested and refined, they are fabricated and become static parts of the network. They can work only at specific wavelengths and specific performance levels. Campione and others are working to make these filters more flexible by designing active devices, which use external stimuli to tell the device to reconfigure itself, e.g. when it is time to change frequency of operation. Today’s communication network consists of many devices, each performing its own separate function. Metamaterials may allow us to design devices with multiple functionalities. By using such devices, networks will be faster, cheaper, more efficient and use less space – and be more responsive to each user’s individual needs.
One of the human body’s defense mechanisms is to destroy foreign objects that invade it. Nanostructures are so small that they can be put into the body without the body trying to destroy them. This ability to exist within the human body, to be designed for specific purposes and to be controlled by scientists makes nanostructures ideal for fighting cancer. Scientists can put a specially designed nanostructure into the body, move it to the location of the carcinogenic cells and illuminate those cells with electromagnetic radiation. The nanostructures then absorb the energy, heat up and destroy the bad cells. This allows an incredibly targeted approach to isolating and killing deadly cells in the body.
In the Environment
There are many environments in which toxins and chemicals need to be kept at or below specific levels to keep employees in those environments safe. From oil fields, where certain chemicals need to be kept at low enough concentrations to prevent ignition, to semiconductor manufacturing, where dust inhalation can be fatal, nanosensing devices have the potential to provide a much more granular level of accuracy than current sensing technologies. Each of the elements in these environments might need to be sensed at different frequencies and sensors can be built to detect specific molecules. Since some of these toxins can be dangerous even in very limited quantities, extremely high levels of sensitivity are required to detect and react to environmental hazards.
This intersection of physics, engineering and chemistry helps us create solutions that we would not have thought possible even twenty years ago. With applications ranging from seismic protection to cloaking devices that make aircraft invisible to radar, these new metamaterial-based building blocks will be a key part of our future.
1. Wikipedia: https://en.wikipedia.org/wiki/Metamaterial