Rensselaer Alumni Magazine - Winter 2011-12 - (Page 12)
Graphene Nanoelectronics for a Post-Silicon World
travel through the copper nanowires COPPER’S DAYS ARE NUMBERED, AND A sluggishly and generate intense heat. new study at Rensselaer could hasten As a result, the electrons “drag” the downfall of the ubiquitous metal in atoms of copper around with them. smartphones, tablet computers, and These misplaced atoms increase nearly all electronics. This is good the copper wire’s electrical resistance, news for technophiles who are seeking and degrade the wire’s ability to smaller, faster devices. transport electrons. This means fewer As new generations of computer electrons are able to pass through the chips continue to shrink in size, so do copper successfully, and any lingering the copper pathways that transport electrons are expressed as heat. electricity and information around the This heat can have negative effects labyrinth of transistors and components. on both a computer chip’s speed When these pathways—called interand performance. connects—grow smaller, they become A new study from researchers at Rensselaer details how stacking nanoribbons When cut into nanoribbons, less efficient, consume more power, and of graphene can boost the material’s ability to transmit electrical charges. graphene is known to exhibit a band are more prone to permanent failure. gap—an energy gap between the valence and realizing graphene nanoelectronics and namTo overcome this hurdle, industry and conduction bands—which is an unattractive ing graphene as the heir apparent to copper. academia are researching new candidates to property for interconnects. The new study “Graphene shows enormous potential for succeed traditional copper as the material of shows that stacking the graphene nanoribbons use in interconnects, and stacking up graphene choice for interconnects on computer chips. on top of each other, however, could signifishows a viable way to mass produce these One promising candidate is graphene, an cantly shrink this band gap. structures,” says Nayak, professor of physics, atom-thick sheet of carbon atoms arranged The end destination, Nayak says, is to one applied physics, and astronomy. Our new study like a nanoscale chicken-wire fence. day manufacture microprocessors—both the makes a case for the possibility that stacks of Led by Professor Saroj Nayak, a team interconnects and the transistors—entirely graphene ribbons could have what it takes to of researchers discovered they could enhance out of graphene. This game-changing goal, be used as interconnects in integrated circuits.” the ability of graphene to transmit electricity called monolithic integration, would mean the Copper interconnects suffer from a variety by stacking several thin graphene ribbons on end of the long era of copper interconnects of problems, which grow more prominent as top of one another. The study, published in the and silicon transistors. the size of the interconnects shrinks. Electrons journal ACS Nano, brings industry closer to
Researcher Wins $1.4 Million NIH Grant To Study Regeneration of Nerves
Engineers “Cook” New Heat-Harvesting Nanomaterials
A team of researchers led by Ganpati Ramanath, professor of materials science and engineering, in collaboration with the University of Wollongong, Australia, have demonstrated a new way to decrease zinc oxide’s thermal conductivity without reducing its electrical conductivity. This work could open the door to new technologies for harvesting waste heat and creating highly energy efficient cars, aircraft, power plants, and other systems. Harvesting electricity from waste heat requires a material that is good at conducting electricity but poor at conducting heat. One of the most promising candidates for this job is zinc oxide, a nontoxic, inexpensive material with a high melting point. However, while nanoengineering techniques exist for boosting the electrical conductivity of zinc oxide, the material’s high thermal conductivity is a roadblock to its effectiveness in collecting and converting waste heat. The innovation involves adding minute amounts of aluminum to zinc oxide, and processing the materials in a microwave oven. To learn more about research at Rensselaer, go to www.rpi.edu/research.
With a new $1.4 million grant from the National Institutes of Health (NIH), Deanna Thompson, associate professor of biomedical engineering, will investigate a promising new method to heal traumatic nerve damage, using electrical stimulation to prime and pump neuronal growth. The research looks specifically at healing the peripheral nervous system, which is the system of nerves outside of the brain and spinal cord that extends throughout the rest of the body. The system has a greater ability to repair itself compared to the central nervous system housed in the brain and spinal cord, but patients with severe injuries to the peripheral nervous system rarely regain full function. Thompson and her colleagues will further pursue some promising discoveries that they have already made on how nerve repair can be stimulated and directed to repair large-gap injuries that cannot spontaneously regenerate. Thompson wants to see the effective tools used for bone and wound healing one day applied to restore nerve function following trauma.
12 RENSSELAER/WINTER 2011-12
Table of Contents for the Digital Edition of Rensselaer Alumni Magazine - Winter 2011-12
Rensselaer Alumni Magazine - Winter 2012
Taking Care of Business
One Last Thing
Rensselaer Alumni Magazine - Winter 2011-12