Nanotechnology Roundup
9 May 2008, 18:10
Categories: other
Nanomaterials have a relatively larger surface area when compared to the same mass of material in bulk form, which can make the materials more chemically reactive and affect their strength or electrical properties. Additionally, quantum effects can begin to dominate the behavior of matter at the nanoscale, affecting the optical, electrical and magnetic behavior of materials. For example, metals with a so-called grain size of around 10 nanometers are as much as seven times harder and tougher than their ordinary counterparts with grain sizes in the hundreds of nanometers.
Despite its promise, one of the main problems facing nanotechnology is the confusion about its definition. Most definitions revolve around the study and control of phenomena and materials at length scales between 1 and 100 nanometers, and the most overused comparison you read about all the time is that with a human hair, which is about 80,000 nm wide. This broad, dimension-based definition has not been entirely useful and is sorely in need of an update to avoid confusion. Some definitions include a reference to molecular systems and devices, and often include “functional systems”. Another important criteria for the definition is the requirement that nanostructures be man-made, and that a nanostructure has special properties that are exclusively due to its nanoscale proportions.
Nanowerk has found a good definition that springs from a recently published article on nanomedicine patent protection. In addition to being practical, the definition is unconstrained by size limitations (source):
The design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.
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Nanowerk also notes that nanotechnology will evolve over a series of technological generations, with each innovation providing a means to produce better products:
First Generation (beginning ∼2000): passive nanostructures, illustrated by nanostructured coatings, nanoparticles, dispersion of nanoparticles, nanocomposites, and bulk nanostructured materials made of metals, polymers, ceramics; bio-building blocks.
Second Generation (beginning ∼2005): active nanostructures, illustrated by transistors, amplifiers, biological and non-biological sensors, actuators, and adaptive structures.
Third Generation (beginning ∼2010): three-dimensional nanosystems and systems of nanosystems using various synthesis and assembly techniques such as bio-assembly, networking at the nanoscale, and multi-scale architectures.
Fourth Generation (beginning ∼2015): materials by design and heterogeneous molecular nanosystems, where each molecule in the nanosystem has a specific structure and plays a different role. Molecules will be used as devices, and from their engineered structures and architectures will emerge fundamentally new functions.
Posted by: The Editors
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