Condensed-Matter and Materials Physics The Science of the World Around Us (2007) / Chapter Skim
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6 What New Discoveries Await Us in the Nanoworld?
6 What New Discoveries Await Us in the Nanoworld?
Pages 111-126
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From page 111... ...
For example, nanocrystals of semiconductors can melt at temperatures hundreds of degrees lower than the temperatures at which bulk materials melt, allowing thin films to be recrystallized with a hair dryer instead of a furnace. Carbon nanotubes and quantum dots form single-electron transistors that turn from on to off with the addition of a single elementary charge.
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From page 112... ...
patterned by a single class of lithography based techniques, and aimed at one major goal, the manipulation of electronic information. The goal of nanoscience is to perform the fundamental scientific studies needed to create even more nanotechnologies, ones capable of manipulat ing matter, energy, and light the way that integrated circuits manipulate electrons.
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From page 113... ...
Personalized medicine will become a reality, allowing each of us to have a map of our own genomes so that doctors can tailor therapeutic solutions to the individual's makeup. Nanoscale Structures: How do we build them?
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From page 114... ...
A key goal in the coming decade will be to train scientists who are capable of combining all of these approaches. Patterning at the Nanoscale: Lithography and Self-Assembly Modern lithographic techniques allow researchers to pattern materials into devices with dimensions down to approximately 30 nanometers (nm)
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From page 115... ...
, synthesized with varying functionalities (electronic, optical, magnetic, and so forth) , results in the formation of various geometric structures (spheres, cylinders, lamellae, and so forth)
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From page 116... ...
The properties of carbon nanotubes have received tremendous attention over the past decade, but a major roadblock looms for applications. There are still no protocols to grow precisely positioned, structurally identical carbon nanotubes of a desired length, diameter, and chirality.
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From page 117... ...
The future challenge is to create nanoscale building blocks with built-in functionality -- ones that can move, change, and assemble in specific ways. The way that nature does this is a stounding -- constructing machines out of a linear string of elements that folds
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From page 118... ...
Studying Nanostructure Building Blocks: The Atomic Physics of Nanoscience Understanding the properties of individual atoms lies at the heart of the physics and chemistry of solids. Similarly, a thorough and complete understanding of the properties of nanoscale building blocks is central to the field of nanoscience and FIGURE 6.4 Rationally designed DNA assembly of a complex nanoscale structure.
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From page 119... ...
Researchers are on the verge of measuring the quantum fluctuations of a mechanical beam, demonstrating that the quantum rules of behavior can apply to objects consisting of millions of atoms. Also of interest are the interactions between different kinds of quantum systems -- single electrons interacting with a mechanical resonator, or a single quantum dot coupled National Research Council, Controlling the Quantum World: The Science of Atoms, Molecules, and Photons, Washington, D.C.: The National Academies Press, 2007.
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From page 120... ...
However, researchers have recently shown that a variety of cleverly designed nanostructures can confine or guide light on a scale smaller than previously thought possible. Using either dielectric waveguides on a silicon chip or metal structures whose plasma excitations guide light, researchers are bringing light down to the nanoscale for applications ranging from biomolecu lar detection to information processing.
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From page 121... ...
New techniques to tug on individual molecules using optical tweezers or to measure the light coming out of a single molecule using ultrasensitive fluorescence microscopy are answering these questions. For example, consider the virus shown in Figure 6.6.
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From page 122... ...
In small magnetic devices, torques exerted by spin-polarized electrical currents have been developed as a new way to switch ultrasmall magnetic bits. Single e lectron transistors have been used as readouts to measure the quantum properties of mechanical oscillators and electromagnetic resonators.
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From page 123... ...
However, creating periodic solids composed of nanoscale objects has proven to be quite a challenge. With atoms, all the individual subunits are identical, and they readily build extended, nearly perfect arrays.
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From page 124... ...
Another possibility is to assemble the nano-objects using external forces. Re searchers have developed techniques using holographic optical traps to manipulate simultaneously hundreds of micron-scale beads and to control, cut, solder, and place individual nanowires.
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From page 125... ...
While in some cases this is now possible (scanning tunneling microscopy of surface atoms is a prime example) , in general the nanoscientist must infer what his or her sample looks like and how it operates on the basis of a limited amount of direct evidence.
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From page 126... ...
A recent success, over 10 years in the making, was the first detection of a single electron spin using an atomic force microscope. It took years of concentrated ef fort by world-class scientists to bring this to fruition.
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