It was common knowledge that developed countries in the world, such as the United States, Japan, Australia, Canada and European countries, as well as some Asian countries, like Singapore, China, and Korea enterprising middle-intensive to develop a new branch of the popular technology called Nanotechnology. Start funds being poured billions of dollars in these countries, in various fields of research. Overall the race using keywords Nanotechnology. Actually what is nanotechnology? And why are so many researchers in various countries racing to enter the realm of this one? How luaskah scope? Why is this happening just a few years nanotechnology boom?
In accordance with its name, nanotechnology is technology on the nanometer scale, or sepersemilyar meters. To be able to imagine the dimension of nanometers, we can take example from our own bodies.
A human hair has a diameter of approximately 50 micrometers. One micrometer is a thousandth of a millimeter own. And a millimeter is the size of the smallest unit of length on a ruler 30 cm wrote the normal school children. And one nanometer is a thousandth of a micrometer, or roughly equal to the diameter of our hair that has been split 50,000 times! As another comparison, the size of our red blood cells is about 20 micro meters, and the bacterial cell is 2 micro-meter stomach. Protein has a size of several tens of nanometers.
From the viewpoint of the size of the top down (top down) like it, nanotechnology is important in engineering because of the human world trying to integrate a function or working in a smaller scale and smaller. Why? People say, "small is beautiful (small is beautiful)", but, of course, integrate a function of machines or tools in a smaller size means not only memperindahnya but also means to reduce the energy needed by a work function and speed up the process and will also mean mempermurah cost jobs. As an example of our easy to understand is what happens in the world of computers and microprocessors. Manufacturers of microprocessors such as IBM, Intel and Motorola continue to raise the level of integration mikroprosesornya.
Approximately ten to fifteen years ago, the distance between the gate (gate) MOS (metal oxide semiconductor) is 0.75 m, and the level of integration in the 5P 80 386 to 80 486 is approximately 100,000 to 1 million transistors onto a single chip. But, on a Pentium IV, IC processing technology (integrated circuit) which has been successfully used to reduce the distance between the gate to only 0.125 m and reaching the level of integration up to 100 million transistors in a chip-chip.
Smaller distance between the gate means little more time needed to travel an electron (which means faster switching rate) and will also mean little more processor power required. More than that, the more functions that can be integrated in the processor, such as a built-in multimedia, voice processing, and others.
In addition, this IC processing technology also used to integrate functions for mechanical and electrical engineering, sensors or actuators on the size of Milli, micro, until nanometers. Microstructure that integrate mechanical and electrical function is usually called Micro Electro Mechanical System (MEMS). As an example of MEMS technology enables the creation of an array of pressure sensors are so small size (Figure 1) to be placed anywhere in a building structure or machine, for example.
However, if nanotechnology is only struggling with IC and microelectronics engineering are then applied also to mikromekanika? If only the terminology is thus whether the need for such heralded the end; days?
It turns out that nanotechnology is currently booming not only related to conventional top-down engineering IC or MEMS. It all began with a scientific speech Nobel laureate, Richard Feynman in 1959, entitled "'There is Plenty Room at the bottom" (There's plenty of room below), which is now widely cited nanotechnology enthusiasts.
At that Feynman said, it is possible (at least when it is still in the dream) to create a machine so small in size, which can then be used to manipulate material at the size scale. In fact, it was Feynman claimed that, if a physicist equipped "engine" that's right for manipulating atoms and put them in the appropriate place, then he could theoretically make any compound or molecule, of course, a stable energy (stable = minimum energy level ).
Such systems, though not at the atomic level, at least have been there in nature, as has been written also by K. Eric Drexler in the landmark papers in 1981, and introduces the term molecular manufacturing (molecular manufacturing). In her paper, the Drexler gave several examples, how nanometer-sized machines already exist in nature and how they have been involved in the preparation and molecular information in living cells. For example, the ribosomes that make up the amino acids one by one based on RNA, for memfabrikasi protein, then the genetic system (DNA polymerase enzymes, RNA polymerase, etc.) that store and process genetic information, flagella (a kind of structure 'Hair') in bacteria as an activator, and others.
The ability to manipulate materials at the nanometer scale are important, because at this size scale of material begin to form certain properties based on structure. On a smaller level, atomic level (Angstrom scale), which is owned properties is the nature of the atom itself. When the atoms start holding each other and develop a specific molecular structure, nature will vary according to the structure. For example, atomic carbon (C), which when arranged in a tetrahedral three-dimensional structure will form a diamond-hard, but when arranged in two-dimensional hexagonal structure and form layers, so that we find is graphite (pencil raw materials) are fragile.
Nanotechnology is directed at the development of molecular manufacturing methods (eg in the form of 'engine' of nanometer-sized) that can do the preparation of the component atoms or molecules in a regular and controlled to form the desired structure. Model bottom-up fabrication material (bottom-up) as opposed to conventional top-down technology like this would enable very precise control of material properties which are formed (eg free of defect / defects).
Besides reducing the incidence of waste during fabrication because only the atoms / molecules to be used are manipulated (different from top-down methods that often lead to waste due to unused material), and of course the possibility of saving energy also means saving costs. Systems such as photosynthesis in plants is an example of a molecular manufacturing system with high energy efficiency.
The problem then, how the component atoms or molecules can be prepared? As well as approaches to the cells ribosomes, proposed Drexler made "arm-arm" robotic and nano-sized components of other machines that allow for appropriate manufacturing processes on a macro level: the sort of material, energy conversion, material placement, etc..
This method is called Mekanosintesis, doing chemical synthesis mechanically. Some of the nano size of the machine structure (formed from several thousand up to million atoms) have been successfully simulated with a computer, which means mathematically and physically impossible to make. An example is the wall of the space containing the pump rotor material and selectively choose which functions atomic neon (Ne) to be ready to be used in further processing (Figure 2).
The next problem, if such a structure was indeed "possible" (read: stable thermodynamic) to be made, how the process to make the initial structures to be used as machines for the next nano fabrication? And where the driving energy of the beginning?
Some proposed alternatives have begun to try to solve the first problem. Nadrian Seeman tried to make these basic structures of the molecules of DNA (deoxyribonucleic acid, the basic compound gene) by relying on the nature of the self-assemble (self-assembly) of DNA, which binds to adenine and guanine bind Thymin Cytosin.
By synthesizing DNA with specific sequence, Seeman managed to make the basic forms of DNA nanomekanik cubes and devices. Other researchers at NASA Ames Research Center to simulate the use of Carbon Nano Tube (a tubular structure of carbon atoms are synthesized nanometer dimension with the principle of self-assemble from carbon, the use of certain metal catalysts) to form the gear and shaft engine. Gear or shaft structure can be made from carbon nanotubes with a certain chemical reaction to "put the" wheel-shaped cluster of chemical molecules (eg benzene) around the tube .
Another way to arrange the components of an atom or molecule at this early stage is to use nanotechnology instruments, such as the Atomic Force Microscope (Atomic Force Microscope, AFM), and Breakthrough Scanning Electron Microscope (Scanning Tunneling Microscope, STM). The second basic principle is like moving the microscope "hand touch" in the xy coordinate, while maintaining the distance (z coordinate) between the "hand touch" with the sample being studied .
Called "hand touch" because these microscopes are no longer using light as an imaging tool due to lack of light at the nanometer scale (the effect of light diffraction). AFM to detect non-covalent forces (non-chemical bonds, such as electrostatic forces and Van der Waals force) between the samples with a "hand touch", while the electrons from the STM detects breakthrough "hand touch" that penetrates the sample and received by a detector below the sample.
At first, these instruments are limited only used for the purposes of characterization or 'imaging' sample. But, recently, started to be used to manipulate molecules and atoms. By changing the current major breakthrough in STM for example, we can take mereaksikannya with atomic O and CO molecules to form molecules of CO2 and everything is done with single molecule precision. In an ordinary chemical reaction, is required considerable molecular components that react to possible, statistically, the occurrence of "collision" between these molecules.
Regarding the problem of energy supply structure on a nano scale machines, Prof. Montemagno at the University of California at Los Angeles has successfully tried to use bio-natural Nanomotor F1-ATPase to drive the propellers are made with MEMS technology. Bernard Yurke of Bell Labs. using DNA to try to make nano-motors.
Another possible alternative is to combine top-down nanotechnology MEMS with bottom-up nanotechnology. Electric motors and power generation (eg thin film battery) at the micrometer scale with MEMS technology has been widely reported. Next live transmits motion from the motor to the structure of the "arm" robot on a smaller scale - a nanometer.
Nanotechnology dream to be able to manipulate materials with the same level of flexibility that has been achieved with humans in manipulating data with information technology, it may still seem far away and still a lot of homework to do. However, in its development is still too young now, nanotechnology has provided a new color in other areas.
Application of nanotechnology in analytical biotechnology such as permitting new methods far more sensitive and stable than conventional methods. The development of MEMS, which even depart from the conventional IC technologies, still in progress so rapidly, with new applications in optical (appears MOEMS - Micro Optical Electro Mechanical Systems), integrated in the system of non-wire sensors, and also in the application of RF (Radio Frequency)-MEMS.
On the development of nanotechnology is so feels, how the background science and technology is needed multi-discipline: mathematical modeling, physics for understanding the phenomena of style and energy, chemical (inorganic or organic) to the understanding of material properties, as well as biology to learning-system engineering systems in living organisms.
Besides the creativity and creation of high power is needed to find the breakthrough new techniques and methods, as well as a suitable application. Of course, the moral and religious grandeur remains necessary to the application of this technology does not actually harm the survival of mankind.
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