Microtechnology is the use of compact, or very small, technical devices. Microtechnology embraces microcomputer parts, space microdevices, microsurgery, and microelectronics. Both microfilm and microfiche, which store information on film, are also examples of microtechnology; microfiche generally stores more than microfilm. The term micro, derived from the Greek word mikros, meaning small, is used to describe something that is unusually small.
Technology is the application of inventions and discoveries to meet needs or obtain goals. Microtechnology has the advantages of taking up less space, using less construction material, and costing less money. Initial manufacturing of such small components requires invention or reapplication of existing technology, a trained manufacturer, and precise manufacturing conditions. The resulting smaller equipment is less expensive to transport and store; this aspect of microtechnology makes it ideally suited for use, for example, in outer space.
Microtechnology has emerged in various technological fields since about 1920. Advances in scientific knowledge and applications of that knowledge make microtechnology possible. Specific concepts and inventions have provided the necessary basis for micro-technology. These significant inventions include: the microscope, electricity, computers, and lasers. For example, microscopes allow technicians to view minute regions of computer microprocessors and components of other microdevices. Microscopes also enable surgeons to view aspects of a patient’s body at a resolution not possible for the naked human eye.
Not long after the computer was invented, engineers began to make improvements that increased computer functions and decreased computer size. Today’s computers contain many microcomputer components— the primary one is the microprocessor, a type of microchip. A microprocessor contains the entire computer central processing unit on a single chip.
Microchips come in a range of sizes and generally are smaller than 0.08 sq in (2 sq mm). They are made of a slice of semiconducting material such as silicon or germanium and have specific electrical characteristics. The first microchips were made in the early 1960s. Some microchips are microprocessors; others can be memory or interface microchips. The microprocessor chip communicates with memory and interface chips within the computer through buses, or series of wires, that relay information.
Microcomputers are embedded in and control numerous modern devices such as automobiles, digital watches, telephones, and video cameras. The microelectronic circuits of these embedded computers are called integrated circuits. The miniature onboard circuitry is housed in the chips.
Computer microtechnology also uses laser technology. Lasers (the name is an acronym for light amplification by stimulated emission radiation) are focused beams of light, amplified among opposing mirrors. American physicist Theodore Harold Maiman (1927–) is considered the first person to have invented an operable laser; which he did in 1960. Directed light has extraordinary specificity; a laser light can drill over 100 holes into the head of a pin. Lasers are used to guide missiles, align walls and ceilings of buildings under construction, print, and detect minuscule movements of Earth’s continents in the phenomenon of continental drift. All lasers have three major components: a light source, opposing mirrors that intensify the light beam, and an amplifying medium. Lasers are classified according to their amplifying medium and are generally of four types: semiconductor, solid state, gas, or dye. A laser beam can be directed through the ground and around corners. Laser light is used in communication because it can be conducted along glass fiberoptic cables, without much signal loss.
Laser microtechnology has many applications. Machines can use laser light to read or scan information. Bar code scanners in grocery stores routinely register product identification and cost with laser scanners. Lasers are also used to cut materials such as cloth and to weld metals. In addition, lasers (particularly CO2 lasers) are used in medicine. Lasers are used surgically and for specific medical applications like shattering gallstones. Laser beams guide weapons, such as missiles, that contain laser designators that can detect and follow the laser light path. Some lasers are as small as a grain of sand.
Several micro-technological applications exist in both science and medicine. Scientists use microscopes, micropipettes, microtomes, microelectrodes, and microcapsules in research. Surgeons use microscopes, micromanipulators, and microinstruments in microsurgery.
Scientists use microscopes to observe objects less than 0.004 in (0.1 mm) in diameter. Scientists can also make thin slices of microscopic substances, including living material, with a microtome. Micropipettes are miniature pipettes (hollow needles) used to inject substances into something else, such as a cell. Microelectrodes can measure an electrical charge across a cellular membrane; microelectrodes are also used to detect intracellular ionic flow that can signify other important changes in cells. Microcapsules release their contents at set temperatures and pressures and can be used in chemical, physical, and biochemical experiments to supply a substance at a set point.
In medical microsurgery, surgeons observe a patient’s tissues through a microscope to make highly precise alterations to areas such as the eyes (cataract removal or corneal transplant), ears (middle ear bone replacement), larynx, blood vessels, cervix, fallopian tubes (obstruction removal), vas deferens (vasectomy reversal), and severed appendages and nerves. Microsurgery can be accomplished either with delicate surgical instruments held by the surgeon while viewing the surgical area under the microscope or by a micro-manipulator using microinstruments. A micromanipulator is a human-guided or programmed machine (much like a robot) that manipulates microinstruments to perform surgical procedures. Lasers are invaluable to medical microsurgery because they can be used to make extremely precise surgical cuts. Laser surgery is also used to remove some skin lesions.
Any device sent into outer space must have certain characteristics. It must be able to withstand the stress of propulsion into space. It must also be able to use power efficiently. In addition, it must be able to operate under thermal extremes. It is also very favorable for such devices to be as small and lightweight as possible. Several space microdevices have been created that meet these criteria. Miniature gas chromatographic ionization detectors, ion mobility spectrometers, x-ray diffraction devices, and fluorescence instruments are all in various stages of development. Each of these devices plays an important role in exobiology, the science of extraterrestrial environments that may support life.
A number of space microdevices have micromechanical functions; they either sense or respond to detected conditions such as the presence of a chemical or heat. Ionization detectors can identify the chemical composition of a foreign sample. Model ionization detectors weigh only 0.008 to 0.06 oz (1 to 2 g), and are sensitive enough to detect compounds at 10-14 mol/sec. A miniature stable isotope laserdiode spectrometer has also been designed to determine sample ratios
Exobiology— The science of extraterrestrial life forms and environments that may support life.
Laser— A minute, focused beam of light that can be adapted to many uses. An acronym for Light Amplification by Stimulated Emission Radiation.
Microchip— A chip of semiconducting material containing an electrical circuit that can process or store information.
Microelectronics— Highly miniaturized electronic circuitry.
Microprocessor— A microchip that houses a computer’s entire central processing unit, the speed of which is limited by the conducting material comprising the chip.
Microsurgery— Surgery performed with visual assistance of a microscope that can also use micromanipulation of microinstruments.
of carbon and oxygen isotopes. These advances in miniature space technology could help decrease the size and weight of the space vehicle’s payload (cargo not required for basic travel operations).
Micromachines with thousands of other uses are on the drawing board, in the laboratory, and soon to be part of daily lives. For years, intricate miniatures have been the pride of craftspeople that used intricate watches and toys to display their finesse. The twentieth century developments of silicon chips and electronics are now allowing tiny twenty-first century machines with science fictionlike capabilities. The first micromachine to catch the public’s eye was probably the electric motor developed by engineers at the University of California in 1988 the motor was half as wide as a human hair. In 1996, the Japanese followed with a complete car, a replica of a 1936 Toyota sedan, which was the size of a grain of rice and had 24 moving parts. Micromachines have three dimensions (as opposed to the flat, essentially two-dimensional chips) and usually consist of a sensor, actuator, and motor or pump. They are called MEMS, an acronym for micro-electrical mechanical systems. MEMS have endless practical uses and are already employed to sense when to deploy airbags in automobiles and to measure blood pressure from inside intravenous tubes (IV) in hospitals.
Micro-air vehicles, or MAVS, are bug-sized devices that fly and are also called entomopters. Despite the cute images they conjure, MAVS might have potential as miniature spy planes in hotel rooms, as flying cameras in any number of applications including security systems, and as collectors of air samples in contaminated areas or following explosions. After disasters like earthquakes, MAVS may be dispatched in buildings to search for survivors without imperiling rescuers. The cousins of MAVS are MARVS, or miniature autonomous robotic vehicles. MARVS can also be sent on dangerous missions to inspect for chemical or nuclear weapons, detect leaks, or search for land mines. MARVS navigate on tiny wheels, so obstacles like paperclips or pencils are major. Other hazards that face these tiny devices and their creators are static electricity that can paralyze gears, oils and residues that clog motors, and droplets of rain that impact the machines like bombs. But MEMS are inexpensive to mass produce, and they do not experience the problems of larger machines like metal fatigue.
See also Nanotechnology.
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