Can a tiny structure, 10,000 times thinner than a human hair, provide us with the answers to the world’s greatest challenges? Scientists at IBM think the answer is yes.
Nano comes from the Greek word for “dwarf” and broadly speaking, the field of nanotechnology can be defined as research and technology developments at the atomic or molecular level. Researchers in nanotechnology seek to understand and control some of the smallest objects known to humankind.
In terms of length, one nanometer is the equivalent of about four gold atoms or one millionth of a millimeter. Or to use an analogy, the diameter of an atom compares to the diameter of an orange as the orange compares to the Earth.
As the world becomes more instrumented, with billions of transistors embedded in everything from cars to appliances to livestock, nanotechnology will play an increasingly important role in the design of future computer chips that are smaller, smarter and more energy efficient.
To achieve these performance goals, sophisticated nanotechnology processes are needed to fabricate these increasingly small transistors. Just as cells are the basic building blocks for the human body, IBM envisions a world in which nanotechnology processes are the basic building blocks for transistors and microprocessors. IBM scientists are exploring the use of new materials, such as semiconducting nanowires, to improve the fundamental design of transistors, which is more than 50 years old.
IBM Research opened the door to the world of nanoscience in 1981 when Gerd Binnig and Heinrich Rohrer invented the scanning tunneling microscope, revolutionizing our ability to manipulate solid surfaces the size of atoms. [Read more about the Icon of Progress, Scanning Tunneling Microscope]. And since that time, IBM has achieved breakthrough upon breakthrough in the field.
In 1993, NEC researcher Sumio Iijima and IBM researcher Donald S. Bethune had independently discovered a unique new form of carbon called single-walled carbon nanotubes, “which can behave like metals or semiconductors, can conduct electricity better than copper, can transmit heat better than diamond, and rank among the strongest materials known.”*
Then in 1998, an individual carbon nanotube was made into a transistor by a group—which included Phaedon Avouris, who later joined IBM—in Delft, Netherlands, and by a team at IBM. IBM continued the work and demonstrated that nanotubes could potentially scale up as building blocks for the future of electronics.
In 2001, this IBM team, led by Dr. Avouris, who had become manager of nanoscale science at IBM Research in Yorktown Heights, NY, devised the first transistors using arrays of carbon nanotubes. Nanotubes conduct electricity at rates that are approximately 70 times higher than silicon. Avouris’ team, which included Vincent Derycke, Richard Martel and Joerg Appenzeller, also succeeded in integrating the carbon nanotubes with existing chip-making technologies. Later that year, the IBM researchers announced they had built the world’s first circuit using an individual carbon nanotube that could perform a basic logic operation.
In 2002, IBM Research scientists proved that transistors based on carbon nanotubes could switch on and off faster and use less energy than current transistors etched into silicon chips. And most recently, IBM Research scientists in Zurich, Switzerland, have been able to capture an image of the “anatomy”—or chemical structure—inside a molecule with unprecedented resolution.
“What certainly is going to happen is that these nanotubes are going to be used in damned near any area you can think of where electrons move from here to there. And like all other new things, it’s going to have to find niches in which it’s competitive to displace the existing answers.”
“Mega Steps Toward the Nanochip,” WiredApril 27, 2001
“For a long time people had dreamed of making a circuit out of a molecule. But now we can make devices.”
“IBM’s carbon nanotube FET hints at post-silicon circuits,” EE TimesOctober 5, 2001
“…we’re talking about devices that are drastically smaller, and because their key components are fabricated by chemical synthesis, they can be drastically cheaper than silicon transistors.”
“Mega Steps Toward the Nanochip,” WiredApril 27, 2001
“This breakthrough in antimicrobial research represents another example of how scientists are expanding beyond traditional boundaries by applying lessons learned from other research fields. Our combined materials development and bioengineering expertise enabled us to discover a new way to potentially treat infectious diseases.”
“IBN and IBM co-develop new weapon against drug-resistant superbugs,” Knowledge Transfer NetworkApril 4, 2011
“Though not an exact comparison, if you think about how a doctor uses an X-ray to image bones and organs inside the human body, we are using the atomic force microscope to image the atomic structures that are the backbones of individual molecules,” said IBM researcher Gerhard Meyer. “Scanning probe techniques offer amazing potential for prototyping complex functional structures and for tailoring and studying their electronic and chemical properties on the atomic scale.”
Today, interest in carbon electronics has expanded to include transistors and circuits made with graphene, a single atom-thick layer of carbon atoms bonded in a hexagonal honeycomb-like arrangement. In 2010, Avouris’ team at IBM demonstrated the world’s fastest graphene transistor, capable of switching at a rate of 100 billion times a second, or 100 gigahertz. Most recently, this team produced the first graphene-integrated circuit, a radio-frequency mixer. (A mixer is used in radios and other communications equipment to switch a signal up or down to another frequency.) The same team applied graphene in optoelectronics and demonstrated the use of a single atomic layer of graphene to reliably detect optical data streams at rates of 10 gigabits per second. Graphene has many advantages because it can be used as a universal—meaning it has very wide wavelength range—photodetector. Graphene also has an ultrafast response and is inexpensive.
The benefits of nanotechnology, however, extend beyond electronics. Nanoscale systems are already being tested by different companies to improve solar energy, water purification and desalination in the emerging markets, and to enable faster and more accurate healthcare diagnostic tools—such as the
The most recent development in applying nanoscience to medicine is the development of a potential weapon against Methicillin-resistant Staphylococcus aureus (MRSA), an easily contracted form of Staph infection, which causes tens of thousands of hospital-stay deaths in the United States every year. When the Staph bacteria develops resistance to antibiotics, it can be deadly. IBM researchers have discovered a potential breakthrough method of treatment in which nanostructures are able to detect and destroy the antibiotic-resistant bacteria while leaving the healthy cells intact. Scientists used principles from semiconductor manufacturing and found that certain polymers can locate bacteria and break through the bacterial cell wall and membrane. When the membrane is destroyed, the cells are unable to mutate into antibiotic-resistant bacteria. The nanostructures, when finished fighting the bacteria, biodegrade in the body and are eliminated. While still experimental, using nanotechnology in this way could be a potential breakthrough in how to treat this disease.
With all of this potential, it’s no surprise that nanotechnology is attracting increasing attention from all over the world, and governments from the United States to Switzerland to Jordan to China are all investing in the science. IBM extended its commitment to the future of nanotechnology research and innovations in May 2011 with the opening of the Binnig and Rohrer Nanotechnology Center on the IBM Research campus in Zurich. The Center is a unique collaboration with ETH Zurich, a premier European science and engineering university.
* Citation to Sumio Iijima and Donald S. Bethune, James C. McGroddy Prize for New Materials, American Physical Society, March 2002