A team of chemists at Lund University in Sweden has recorded the formation of nanowires in real time with an electron microscope. Not long after, a team of biologists at Michigan State University discovered organic nanowires that could be used for electronic devices. Both discoveries have potential for use in electronics, but the way they were formed and their potential applications are vastly different.
What is a Nanowire?
Nanowires, also known as quantum wires, are incredibly small wires just a few nanometers thick. They're so small that the effects of quantum mechanics are applicable at such a small level. So far nanowires with a few different helpful properties have been discovered, these properties depend on elements and compounds that they are derived from. There are superconducting nanowires made from yttrium barium copper oxide (YBCO), metallic nanowires made from nickel, platinum, or gold; semiconducting nanowires made from silicon and other compounds, insulating nanowires made from silicon or titanium dioxide, and molecular nanowires.
A polyaniline nanowire bundle, courtesy of MSU's Nano-Biosensors Lab
Until recently, molecular nanowires were not known to have properties that made them applicable to electronics, and we only had a vague idea of how specific nanowire compounds are formed.
Lund University's Super Electron Microscope
Scientists have come a step closer to having the ability to make nanowires for semiconductors into compositions and structures of their choosing. Researchers have known how nanowires form for years but have never been able to observe the phenomenon well enough to manipulate their growth to achieve their desired goals. The researchers in Lund can now experiment with the nanowires' growth by exposing them to different elements to see the results, essentially giving them the ability to do chemistry experiments at the atomic level. Daniel Jacobsson, a research engineer at Lund University elaborated on this discovery in an article written for Nature.com:
"We now have on tape the events that take place, and what is required to be able to control the nanowire growth"
The research team is also developing an even more powerful electron microscope in order to provide more insight into the nanowire growth process. If scientists can successfully recreate the conditions for their desired nanowire compounds, microchips will become smaller and faster than ever. This might even kick Moore's Law up a notch!
Michigan State's Microbial Protein Fiber
A research team at Michigan State University led by Gemma Reguera has discovered a microbial protein fiber that can transfer electrons fast enough for application in man-made devices. The protein fibers are pili, which are the dangly appendages on bacteria and other microbes. These fibers were produced by Geobacter, bacteria that consume oil pollutants and radioactive waste, leaving carbon dioxide as waste. This particular fiber was discovered when using Geobacter bacteria to consume Uranium. What makes this new fiber so intriguing is that can transport charges at a speed of 1 billion electrons per second. This is the first organic material discovered with these properties.
"Being made of protein, these organic nanowires are biodegradable and biocompatible" -Gemma Reguera
Dr. Reguera at work. Image courtesy of MSU's Kurt Stepnitz
The significance of this discovery is that the new fiber is both environmentally friendly, easier to synthesize, and usable in medical devices that can be used inside the human body.
"This contrasts dramatically with the manufacturing of man-made inorganic nanowires, which involve high temperatures, toxic solvents, vacuums and specialized equipment."
Both of these new developments sound great in theory, but only time will tell if they can be applied to electronics successfully. For now, we'll just have to enjoy geeking out about the theoritical applications.