Physics professor uses nanotechnology and lasers to create new ‘high-tech’ future
Imagine a world with television screens on your t-shirts and computers that run on flashes of light. No longer limited to the realm of science fiction, such technologies are approaching achievability, thanks to the research of physicists like professor Shabbir Mian.
Mian recently returned from sabbatical at University College London where he performed research involving graphene and photonic crystals that could lead to those possibilities becoming realities. He also used his sabbatical leave at the fourth-ranked university in the world to develop a new online course, “Introduction to Astronomy,” and redesigned another one called “Understanding the Universe,” both of which were offered this summer at McDaniel on the undergraduate level.
Mian believes “high-tech” is the future of American industry. For example, graphene can be used as an electrode in organic light-emitting diode (OLED), which would be a significantly more energy-efficient and flexible LED light. He explained this would allow for “bendy pixels.”
This is an OLED device Dr. Mian made at UCL. The metal electrodes at the top are only 150 nanometer thick (one nanometer is one billionth of one meter). “The OLED is layered like a sandwich,” Mian explained, with an entire thickness of 300-400 nanometers.
“Revolutionary OLED TVs have just made their way into the market,” he said of curved screens meant to give viewers an IMAX experience at home. Such televisions operate with the technologies Mian has studied during his sabbatical. He estimates that OLED TVs might become more affordable in as few as five years.
Graphene, a form of carbon, is not currently used in OLED devices, but because of its unique conductivity, flexibility and transparency, one-atom-thick graphene electrodes would allow for the creation of what Mian calls “bendy pixels” that could one day be used to create screens on fabric.
Mian said that nanoflakes, or “microscopic cornflakes,” of graphene are small enough to be used as an electrode, but less effective at conducting electricity than larger sheets. Mian tried to solve this problem with an electron extractor, which he said showed some promise.
The next necessary component to a flexible screen is the material in an OLED that actually emits light. Mian says semiconducting polymers would be perfect for the flexible “next generation” of OLED TVs. His sabbatical research also involved exploring which of these polymers work efficiently with graphene electrodes.
Another aspect of his high-tech future involves replacing electric signals with laser pulses. Mian, a photonics specialist, explained this process that has already begun through the widespread use of fiber optics that transmit information through light.
“The whole idea of photonics is to replace the bulky electronic stuff we have with things that run on light, or laser pulses,” he said, gesturing toward his computer and all of the cords and accessories that accompany it.
This is the OLED device glowing in an experiment. With the metal electrodes now in the back, the light is coming from a semiconducting polymer through the transparent electrode in the front.
This was the basis of his other major sabbatical project on photonic crystals. Mian explored how adjusting the sizes and patterns of microscopic holes in silicon wafers changes how these wafers interact with light.
This research opens the doors for microlasers that would be tunable to different colors. “Each color can be coded with different information,” he said.
Unlike electrical signals that can only travel in one direction at a time, light waves can travel through each other, Mian explained. Different colors of light can travel in oppositional directions within the same waveguide, which is like a cord for light.
“This means that the road is no longer one-way, but can be both ways without increasing the size of the road,” said Mian.
Physicists like Mian are working toward a future where optics will replace electricity in every aspect except as the power source for lasers. As for when that will happen, Mian said, smiling, “We’ll have to wait and see.”
Mian expects to get at least one paper out of each major sabbatical research project. One group paper about photonic crystals has already been accepted for presentation at a London conference.