Portal:Nanotechnology

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Welcome to the nanotechnology portal
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Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometers.

Nanotechnology is very diverse, including extensions of conventional device physics, new approaches based on molecular self-assembly, developing new materials with nanoscale dimensions, and investigating whether we can directly control matter on the atomic scale. Nanotechnology entails the application of fields as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.

There is much debate on the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios.

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Schematic diagram of a scanning tunneling microscope.

Scanning tunneling microscope

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A scanning tunneling microscope (STM) is an instrument for imaging surfaces at the atomic level. Its development in 1981 earned its inventors, Gerd Binnig and Heinrich Rohrer (at IBM Zürich), the Nobel Prize in Physics in 1986. For an STM, good resolution is considered to be 0.1 nm lateral resolution and 0.01 nm depth resolution.With this resolution, individual atoms within materials are routinely imaged and manipulated. The STM can be used not only in ultra-high vacuum but also in air, water, and various other liquid or gas ambients, and at temperatures ranging from near zero kelvin to a few hundred degrees Celsius.

The STM is based on the concept of quantum tunneling. When a conducting tip is brought very near to the surface to be examined, a bias (voltage difference) applied between the two can allow electrons to tunnel through the vacuum between them. The resulting tunneling current is a function of tip position, applied voltage, and the local density of states (LDOS) of the sample. Information is acquired by monitoring the current as the tip's position scans across the surface, and is usually displayed in image form. STM can be a challenging technique, as it requires extremely clean and stable surfaces, sharp tips, excellent vibration control, and sophisticated electronics. The components of an STM include scanning tip, piezoelectric controlled height and x,y scanner, coarse sample-to-tip control, vibration isolation system, and computer. The tip is often made of tungsten or platinum-iridium, though gold is also used.

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Atom probe

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Visualisation of data obtained from an atom probe, each point represents a reconstructed atom position from detected evaporated ions.
Credit: C. B. Ene

Visualisation of data obtained from an atom probe

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Don Eigler in 2007 with his two dogs Neon and Argon

Don Eigler

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Donald M. Eigler is an American physicist at the IBM Almaden Research Center. In 1989, he was the first to use a scanning tunneling microscope tip to arrange individual atoms on a surface, famously spelling out the letters "IBM" with 35 xenon atoms. He later went on to create the first quantum corrals as well as nanoscale logic circuits using individual atoms of carbon monoxide. He was shared the 2010 Kavli Prize in Nanoscience for "development of unprecedented methods to control matter on the nanoscale".

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