Nanotechnology Breakthroughs by International Business Machines Corporation (IBM)

Source : http://www-03.ibm.com/press/attachments/28488.pdf

 

In chronological order:

 

1981 - IBM scientists invent the  Scanning Tunneling Microscope, giving ready access for the first time to the nanoscale world of individual atoms and molecules on electrically conducting substrates.

1986 -The  Atomic Force Microscope is invented by IBM and Stanford University scientists, quickly becoming the workhorse of nanoscience, providing general purpose imaging and manipulation in the nanometer realm.

1986 - IBM scientists Gerd Binnig and Heinrich Rohrer win the  Nobel Prize in Physics for the Scanning Tunneling Microscope.

1988 - IBM scientists observe  photon emission from local nanometer-sizes areas stimulated by a scanning tunneling microscope, allowing phenomena such as luminescence and fluorescence to be studied on the nanometer scale.

1989 - IBM Fellow Don Eigler is the  first to controllably manipulate individual atoms on  a surface, using the STM to spell out "I-B-M" by positioning 35 xenon atoms, and in the process, perhaps creating the world’s smallest corporate logo.

1991 -IBM scientists demonstrate an  atomic switch, a significant milestone on the road to the eventual design of electronic devices of atomic dimensions.

1993 – Scientists at IBM and NEC  independently discover single-wall carbon nanotubes and the methods to produce them using metal catalysts.

1996 - IBM scientists extend STM manipulation techniques to  position individual  molecules at room temperature for the first time.

1996 - The  world's smallest abacus is created out of 10 atoms by scientists at IBM, another major milestone in engineering at the nanoscale.

1998 -  IBM scientists and partners discover a molecular wheel, which shows promise for making nanoscale mechanical gears and motors.

 2000 - IBM and university researchers develop nanomechanical sensors using  tiny silicon  fingers to detect minute quantities of biochemical substances and to recognize specific patterns of DNA.

2001 - IBM's "constructive destruction" method overcomes major hurdle for building computer chips beyond silicon with a  method to separate semiconducting and metallic  nanotubes to form a working transistor on the nanoscale

2001 - IBM scientists unveil the  world's first single-molecule computer circuit, carbon nanotube transistors transformed into logic-performing integrated circuits, a major step toward molecular computers.

 

2002 - IBM researchers build world's smallest operating computing circuits using a  molecule cascade, wherein molecules move in a manner analogous to falling dominos.

2003 -- Scientists from IBM, Columbia University and the University of New Orleans demonstrate the first  three-dimensional self assembly of magnetic and semiconducting nanoparticles, a modular assembly method that enables scientists to bring almost any materials together.

2003 - IBM scientists demonstrate the  world's smallest solid-state light emitter, suggesting that carbon nanotubes may be suitable for optoelectroinics.

2004 -- IBM scientists develop a new technique called “spin-flip spectroscopy” to study the properties of atomic-scale magnetic structures. They use this technique to measure  a  fundamental magnetic property of a single atom -- the energy required to flip its magnetic  orientation.

2004 – IBM scientists measure the tiny  magnetic force from a single electron spin using an ultra sensitive magnetic resonance force microscope, showing the potential of vastly extending the sensitivity of magnetic resonance imaging (MRI).

2004 -- IBM scientists  manipulate and control the charge state of individual atoms. This ability to add or remove an electron charge to or from an individual atom can help expand the scope of atom-scale research. Switching between different charge states of an individual atom could enable unprecedented control in the study of chemical reactivity, optical properties, or magnetic moment.

2004 -- IBM scientists make breakthrough in  nanoscale imaging -- the ability to detect the faint magnetic signal from a single electron buried inside a solid sample is a major milestone toward creating a microscope that can make three-dimensional images of molecules with atomic resolution.

2005 -- Using nanoelectronic fabrication technologies, IBM researchers create a tiny device that  slows the speed of light, representing a big advance toward the eventual use of light in place of electricity in the connection of electronic components, potentially leading to vast improvements in the performance of computers and other electronic systems.

2006 -- IBM researchers build the  first complete electronic integrated circuit around a  single “carbon nanotube” molecule, a new material that shows promise for providing enhanced performance over today’s standard silicon semiconductors. The achievement is significant because the circuit was built using standard semiconductor processes and used a single molecule as the base for all components in the circuit, rather than linking together individually-constructed components. This can simplify manufacturing and provide the consistency needed to more thoroughly test and adjust the material for use in these applications.

2006 -- IBM scientists develop a powerful new technique for  exploring and controlling  atomic magnetism, an important tool in the quest not only to understand the operation of future computer circuit and data-storage elements as they shrink toward atomic dimensions, but also to lay the foundation for new materials and computing devices that leverage atom-scale magnetic phenomena.

2006 – In a study investigating the fundamentals of molecular electronics, the  quantum  mechanical effects of attaching gold atoms to a molecule were elucidated. The work demonstrated that it is not only possible to control the atomic-scale geometry of a metal-molecule contact, but also its coupling strength and the phase of the orbital wave function at the contact point.

2007 -- IBM demonstrates the first-ever manufacturing application of "self assembly" used to create a vacuum -- the ultimate insulator -- around nanowires for next-generation microprocessors for its  airgap chip technique.

2007 - IBM researchers in collaboration with scientists from the ETH Zurich demonstrate a new, efficient and precise technique to  “print” at the nanoscale.

2007 - IBM unveils two  nanotechnology breakthroughs as building blocks for atomic structures and devices: Magnetic atom milestone brings single-atom data storage closer to reality; single-molecule switching could lead to molecular computers.

2007 - IBM researchers develop magnetic resonance imaging (MRI) techniques to visualize nanoscale objects. This technique brings  MRI capability to the nanoscale level  for the first time.

2008 - IBM scientists, in collaboration with the University of Regensburg in Germany, are the first ever to measure  the force it takes to move individual atoms on a surface.

2009 – IBM Research builds  microscope with 100 million times finer resolution than current MRI, extending three-dimensional MRI to the nanoscale.

 2009 - IBM scientists reach a landmark in the field of nanoelectronics: the development and demonstration of novel techniques to  measure the distribution of energy and heat in  powered carbon nanotube devices. By employing these techniques, IBM researchers have determined how the energy of electrical currents running through nanotubes is converted into heat and dissipated into collective vibrations of the nanotube's atoms, as well as surface vibrations of the substrate beneath it.

2009 - IBM scientists in collaboration with the University of Regensburg, Germany, and Utrecht University, Netherlands, for the first time demonstrate the ability  to measure the  charge state of individual atoms using non contact atomic force microscopy.

2009 - In an effort to achieve energy-aware computing, the Swiss Federal Institute of Technology Zurich (ETH) and IBM plan to build a  first-of-a-kind water-cooled  supercomputer that will directly repurpose excess heat for the university buildings. The system is expected to save up to 30 tons of CO2 per year, compared to a similar system using today's cooling technologies.

 

2009 – IBM launches new research effort for  next generation electric energy storage, exploring battery technologies to drive electric vehicle adoption and make energy grids more efficient.

 

Breakthrough in transistor fabrication without semiconductors

Michigan Technological University scientists led by professor of physics Yoke Khin Yap have created a quantum tunneling device that acts like like an FET transistor and works at room temperature without using semiconducting materials.

The trick was to use boron nitride nanotubes (BNNTs) with quantum dots made from gold. When sufficient voltage is applied to the device, it switches from insulator to a conducting state. When the voltage is low or turned off, it reverts to its natural state as an insulator. There is no leakage current of electrons escaping from the gold dots into the insulating BNNTs, thus keeping the tunneling channel cool. In contrast, silicon is subject to leakage, which wastes energy in electronic devices and generates a lot of heat, limiting miniaturization of transistors.

Carpets of boron nitride nanotubes, which are insulators and highly resistant to electrical charge were grown on a substrate. Using lasers, quantum dots (QDs) of gold  are deposited as small as three nanometers across on the tops of the BNNTs, forming QDs-BNNTs. BNNTs are the perfect substrates for these quantum dots due to their small, controllable, and uniform diameters, as well as their insulating nature. BNNTs confine the size of the dots that can be deposited. Now if we applied biasing, electrons jumped very precisely from gold dot to gold dot, which is known as quantum tunneling.

Other people have made transistors that exploit quantum tunneling. However, those tunneling field effect transistors have only worked in low temperature. The gold islands have to be on the order of nanometers across to control the electrons at room temperature. If they are too big, too many electrons can flow.

For further reading
http://www.readcube.com/articles/10.1002/adma.201301339?

New material for fuel cell catalyst

Efficient, robust and economical catalyst materials hold the key to achieving a breakthrough in fuel cell technology. Scientists from Jülich and Berlin have developed a material for converting hydrogen and oxygen to water using a tenth of the typical amount of platinum that was previously required. With the aid of state-of-the-art electron microscopy, the researchers discovered that the function of the nanometre-scale catalyst particles is decisively determined by their geometric shape and atomic structure. This discovery opens up the opportunity for further improved catalysts for energy conversion and storage. 

Hydrogen-powered fuel cells are regarded as a clean alternative to conventional combustion engines, as the only substance produced during operation is water. At present, the implementation of hydrogen fuel cells is being hindered by the high material costs of platinum. Large quantities of the expensive noble metal are still required for the electrodes in the fuel cells at which the chemical conversion processes take place. Without the catalytic effect of the platinum, it is not currently possible to achieve the necessary conversion rates.

As catalysis takes place at the surface of the platinum only, material can be saved and, simultaneously, the efficiency of the electrodes improved by using platinum nanoparticles, thus increasing the ratio of platinum surface to material required. Although the tiny particles are around ten thousand times smaller than the diameter of a human hair, the surface area of a kilogram of such particles is huge.

However, more platinum can be saved by mixing it with nickel or copper. Scientist have succeeded in developing efficient metallic catalyst particles for converting hydrogen and oxygen to water using only a tenth of the typical amount of platinum that was previously required. 

The new catalyst consists of octrahedral-shaped nanoparticles of a platinum-nickel alloy. The researchers discovered that the unique manner in which the platinum and nickel atoms arrange themselves on the surfaces to accelerate the chemical reaction between hydrogen and oxygen to form water. Round or cubic particles have different atomic arrangements at the surface and are therefore less effective catalysts for the chemical reaction, which could be compensated by using increased amounts of noble metal.

Thermocrystal: an excellent idea to control the direction of heat by nanoparticle alloy

An MIT scientist has developed a technique that provides a new way of manipulating heat, allowing it to be controlled much as light waves can be manipulated by lenses and mirrors.

The approach relies on engineered materials consisting of nanostructured semiconductor alloy crystals. Heat is a vibration of matter, a vibration of the atomic lattice of a material like sound. Such vibrations can also be thought of as a stream of phonons, which is equivalent to the photons that carry light. The new approach is similar to recently developed photonic crystals that can control the passage of light.

The spacing of tiny gaps in these materials is tuned to match the wavelength of the heat phonons. It’s a completely new way to manipulate heat. Heat differs from sound in the frequency of its vibrations: Sound waves consist of lower frequencies (up to the kilohertz range, or thousands of vibrations per second), while heat arises from higher frequencies (in the terahertz range, or trillions of vibrations per second).

In order to apply the techniques already developed to manipulate sound, first step was to reduce the frequency of the heat phonons, bringing it closer to the sound range. Phonons for sound can travel for kilometres, but phonons of heat only travel for nanometers. That’s why we couldn’t hear heat even with ears.
Heat also spans a wide range of frequencies, while sound spans a single frequency. To get rid of the problem, the first thing to do is to reduce the number of frequencies of hea, bringing these frequencies down into the boundary zone between heat and sound. Making alloys of silicon that incorporate nanoparticles of germanium in a particular size range accomplished this lowering of frequency, scientist found.

Reducing the range of frequencies was also accomplished by making a series of thin films of the material, so that scattering of phonons would take place at the boundaries. This ends up concentrating most of the heat phonons within a relatively narrow window of frequencies.

Following the application of these techniques, more than 40 percent of the total heat flow is concentrated within a hypersonic range and most of the phonons align in a narrow beam, instead of moving in every direction.
As a result, this beam of narrow-frequency phonons can be manipulated using phononic crystals similar to those developed to control sound phonons. Because these crystals are now being used to control heat instead, these are referred to as thermocrystals, a new category of materials.

These thermocrystals might have a wide range of applications, including in improved thermoelectric devices, which convert differences of temperature into electricity. Such devices transmit electricity freely while strictly controlling the flow of heat.

Most conventional materials allow heat to travel in all directions, like ripples expanding outward from a pebble dropped in a pond; thermocrystals could instead produce the equivalent of those ripples only moving out in a single direction. The crystals could also be used to create thermal diodes; materials in which heat can pass in one direction, but not in the reverse direction. Such a one-way heat flow could be useful in energy-efficient buildings in hot and cold climates.

Other variations of the material could be used to focus heat to concentrate it in a small area. Another intriguing possibility is thermal cloaking, materials that prevent detection of heatto shield objects from detection by visible light or microwaves.

For further reading: http://prl.aps.org/pdf/PRL/v110/i2/e025902

Gold nanoparticles to observe the interaction of molecules in liquid

Thanks to a new device that is the size of a human hair, it is now possible to detect molecules in a liquid solution and observe their interactions. This is of major interest for the scientific community, as there is currently no reliable way of examining both the behavior and the chemical structure of molecules in a liquid in real time.

This process could potentially make a whole new class of measurements possible by bringing together infrared detection techniques and gold nanoparticles, which would be a critical step in understanding basic biological functions as well as key aspects of disease progression and treatment. This could also prove useful for studying the behaviour of proteins, medicines and cells in the blood or pollutants in water.

The device is based on infrared absorption spectroscopy. Infrared light can already be used to detect elements: The beam excites the molecules, which start to vibrate in different ways depending on their size, composition and other properties. It's like a guitar string vibrating differently depending on its length. The unique vibration of each type of molecule acts as a signature for that molecule.

This technique works very well in dry environments but not at all well in aqueous environments. A large number of molecules need to be present for them to be detected. It's also more difficult to detect molecules in water, as when the beam goes through the solution, the water molecules vibrate as well and interfere with the target molecule's. To get rid of this problem, the researchers have developed a system capable of isolating the target molecules and eliminating interferences.

The device is made up of miniature fluidic chambers with nano scale gold particles on one side of its cover. Now to catch a particular molecule gold nanoparticle is attached with specific antibodies. Once the target element is introduced in to the small chamber, nanoparticles get attached to the target element. This technique makes it possible to isolate the target molecules from the rest of the liquid. But this is not the only role the nanoparticles play. They are also capable of concentrating light in nanometer-size volumes around their surface as a result of plasmonic resonance.

In the chamber, the beam doesn't need to pass through the whole solution. Instead, it is sent straight to the nanoparticle, which concentrates the light. Caught in the trap, the target molecules are the only ones that are so intensely exposed to the photons. The reaction between the molecules and the infrared photons is extremely strong, which means they can be detected and observed very precisely. This technique enables to observe molecules in-situ as they react with elements in their natural environment. This could prove extremely useful for both medicine and biology.

Electrodes made by Carbon Nanotubes for Recording Neuron Activity

Scientists have been studying how neuron communication in the brain relies on glass and metal electrodes to detect the tiny, high speed synaptic potentials. Yet, nanotechnology offers the possibility of scaling down the electrodes so that individual neurons could be tapped in living, moving animals. Researchers at Duke University are now claiming that they developed electrodes made out of self-entangled carbon nanotubes that are a millimeter long and feature a sub-micron tip. Carbon nanotubes have excellent electrical properties and are incredibly strong for their size. The new needles are small enough to penetrate individual cells and record intracellular electrical activity. The Duke team used the new electrodes to make such recordings in live animals and on brain slices and envision using the new electrodes to record neuronal activity for extended periods in freely moving animals.

The computational complexity of the brain depends in part on a neuron’s capacity to integrate electrochemical information from vast numbers of synaptic inputs. The measurements of synaptic activity that are crucial for mechanistic understanding of brain function are also challenging, because they require intracellular recording methods to detect and resolve millivolt scale synaptic potentials. Although glass electrodes are widely used for intracellular recordings, novel electrodes with superior mechanical and electrical properties are desirable, because they could extend intracellular recording methods to challenging environments, including long term recordings in freely behaving animals. Carbon nanotubes (CNTs) can theoretically deliver this advance, but the difficulty of assembling CNTs has limited their application to a coating layer or assembly on a planar substrate, resulting in electrodes that are more suitable for in vivo extracellular recording or extracellular recording from isolated cells. Here a novel, yet remarkably simple, millimeter-long electrode with a sub-micron tip, fabricated from self-entangled pure CNTs can be used to obtain intracellular and extracellular recordings from vertebrate neurons in vitro and in vivo. This fabrication technology provides a new method for assembling intracellular electrodes from CNTs, affording a promising opportunity to harness nanotechnology for neuroscience applications.