Smart technology that mimics nature
Nanoparticles are able to pass through cell membranes in biological organisms, and their effects are almost completely unknown.
NANOTECHNOLOGY is the control and manipulation of atoms and molecules in the atomic scale. The length scale associated with nanotechnology is between 1 nm to 100 nm. One nanometer is one-billionth of a meter scale. Ten hydrogen atoms put side by side constitute one nanometer. It is anticipated that once this atom by atom manipulation and control is achieved, this will yield unprecedented material properties that can be used in a host of attractive biological, medical, electronic and sensing applications. In one sense, nanotechnology is the imitation of biology in silicon. Nature had been doing nanotechnology for eons within the boundary of cells with amino acids and proteins. Scientists are beginning to realize with awe and wonder the preciseness of such age-old processes. The nanotechnology of biology is so called "wet" nanotechnology. For high speed electronics and sensors, scientists need a "dry" version. Chemists and biologists are interested in the 'wet' part, whereas engineers, physicists and applied scientists are interested with the 'dry' part of nanotechnology. Moore's law predicts that in each eighteen months, computer speed doubles. This implies that the feature sizes in the electronic circuits shrink at an astonishing speed. If this trend continues, then by 2025-30 a stage will come when gate-lengths of transistors, the building blocks of computer chips, will reach a scale that further shrinking is limited by the technology of the day. At the same time, the science that rules solid-state devices will also change. At the atomic scale, quantum mechanics of individual atoms shall have to be considered. At the macro-scale, the individual atomic properties become fuzzy and the rule of average dominates. In the bulk, the rule of the aggregate prevails. But in the atomic scale, even the basic unit of conduction (both heat and electricity) becomes discrete. Besides, the engineers have to consider how to extract the heat generated in such miniscule transistors. This is of great practical concern for chips with nanotransistors to function properly without being burnt out. There is carbon nanotube that has many remarkable properties, e.g. very high electrical conductivity, high resilience and high tensile strength. If the fabrication technology for these nanotubes can be controlled, these nanotubes can make many useful devices in the atomic scale. Recently, some researchers have developed a nanosize AM radio employing only a few carbon nanotubes. In the field of medicine, nanotechnology has great opportunities. Quantum dots (3 dimensional confinement of electrons) can be used as 'tags' for studying and monitoring cancerous cells and molecular activities within human tissues. These quantum tags emit lights of various wavelengths depending on the dots' sizes. Also these nanotags can be made to attach to certain compounds and track those organic compounds within the organ or tissue that is affected. There is a push for better imaging, monitoring and diagnostic tools employing nano materials for the benefit of the health sector. In not very far future, it might be possible to send a nanosize camera inside the human body, take snaps of the ailing tissue and do nanosurgery with the help of nanotools. That is the ultimate goal for nano medicine. Also drug-delivery is an important application. Nanoshells made of some nanomaterials can deliver useful drug right to the ailing cell/tissue. This will reduce the time for diagnostics and risks involved with conventional cancer chemotherapies.
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