06-06-2012, 03:44 PM
NanoTechnology
nanotechnology.doc (Size: 538 KB / Downloads: 1)
Possibilities
The current global enthusiasm for nanotechnology is an offshoot of several late 20th century advances. Of particular importance was the ability to manipulate individual atoms in a controlled fashion—a sort of atomic bricklaying—by techniques such as scanning probe microscopy. Initial successes in producing significant amounts of silver and gold nanoparticles helped to draw even more attention, as did the discovery that materials and devices on the atomic and molecular scales have new and useful properties due in part to surface and quantum effects.
Increasingly Integrated Technologies.
The technologies associated with materials, devices, and systems were once relatively separate, but integration has become the ideal. First, transistors were made into ICs. Next came the integration of micro-optics and micromechanics into devices that were packaged individually and mounted on PCBs. The use of flip chips (where the chip is the package), and placement of passive components within PCBs, are blurring the distinction between devices and systems. The high levels of integration made possible by nanotechnology has made the (very smart) material essentially the device and possibly also the system. Larry Bock, chief executive for Nanosys, recently noted that "nanotech takes the complexity out of the system and puts it in the material".
Manufacturing Advances
Recent advances in top-down manufacturing processes have spurred both micro- and nanotechnologies. Makers of leading-edge ICs use lithography, etching, and deposition to sculpt a substrate such as silicon and build structures on it. Conventional microelectronics has approached the nanometer scale—line widths in chips are near the 100 nm level and are continuing to shrink. MEMS devices are constructed in a similar top-down process. As these processes begin working on smaller and smaller dimensions, they can be used to make a variety of nanotechnology components, much as a large lathe can be used to make small parts in a machine shop.
Computational Design
Recently developed experimental tools, notably synchrotron X-radiation and nuclear magnetic resonance, have revealed the atomic structures of many complex molecules. But this knowledge is not enough; we need to understand the interactions of atoms and molecules in the recognition and sometimes the transduction stages of sensing. The availability of powerful computers and algorithms for simulating nano-scale interactions means that we can design nanosensors computationally, and not just experimentally, by using the molecular dynamics codes and calculations that are already fundamental tools in nanotechnology.
Chemical Sensors
Various nanotube-based gas sensors have been described in the past few years. Modi et al. have developed a miniaturized gas ionization detector based on CNTs. The sensor could be used for gas chromatography.
nanotechnology.doc (Size: 538 KB / Downloads: 1)
Possibilities
The current global enthusiasm for nanotechnology is an offshoot of several late 20th century advances. Of particular importance was the ability to manipulate individual atoms in a controlled fashion—a sort of atomic bricklaying—by techniques such as scanning probe microscopy. Initial successes in producing significant amounts of silver and gold nanoparticles helped to draw even more attention, as did the discovery that materials and devices on the atomic and molecular scales have new and useful properties due in part to surface and quantum effects.
Increasingly Integrated Technologies.
The technologies associated with materials, devices, and systems were once relatively separate, but integration has become the ideal. First, transistors were made into ICs. Next came the integration of micro-optics and micromechanics into devices that were packaged individually and mounted on PCBs. The use of flip chips (where the chip is the package), and placement of passive components within PCBs, are blurring the distinction between devices and systems. The high levels of integration made possible by nanotechnology has made the (very smart) material essentially the device and possibly also the system. Larry Bock, chief executive for Nanosys, recently noted that "nanotech takes the complexity out of the system and puts it in the material".
Manufacturing Advances
Recent advances in top-down manufacturing processes have spurred both micro- and nanotechnologies. Makers of leading-edge ICs use lithography, etching, and deposition to sculpt a substrate such as silicon and build structures on it. Conventional microelectronics has approached the nanometer scale—line widths in chips are near the 100 nm level and are continuing to shrink. MEMS devices are constructed in a similar top-down process. As these processes begin working on smaller and smaller dimensions, they can be used to make a variety of nanotechnology components, much as a large lathe can be used to make small parts in a machine shop.
Computational Design
Recently developed experimental tools, notably synchrotron X-radiation and nuclear magnetic resonance, have revealed the atomic structures of many complex molecules. But this knowledge is not enough; we need to understand the interactions of atoms and molecules in the recognition and sometimes the transduction stages of sensing. The availability of powerful computers and algorithms for simulating nano-scale interactions means that we can design nanosensors computationally, and not just experimentally, by using the molecular dynamics codes and calculations that are already fundamental tools in nanotechnology.
Chemical Sensors
Various nanotube-based gas sensors have been described in the past few years. Modi et al. have developed a miniaturized gas ionization detector based on CNTs. The sensor could be used for gas chromatography.
