Nano in a very small world

One nano (nanometer, symbol: nm) is one billionth of a meter (1 / 1,000,000,000m), a measurement unit for measuring the size of extremely small objects. The smallest structure of matter is atomic size: 0.1nm, molecule is a collection of many atoms: 1nm, bacteria: 50nm, red blood cells: 10,000nm, sperm: 25,000nm, hair fibers : 100,000nm, needle tip: 1 million nm and human height: 2 billion nm.

Nanoscience and nanotechnology (nanoscience and nanotechnology) is a survey subject, investigating the properties of microscopic materials, to manipulate (manipulate), overlap these materials, build larger objects. It is called the method of building from small to larger and bigger objects which are the bottom-up method. The advent of nanoscience and science is revolutionizing the way of thinking and the method of designing all materials from therapeutic pharmaceuticals to electronic components with predetermined characteristics from the scale. death.

Nanotechnology has only just taken the first steps.(Photo: SGTT)

A product of nanotechnology is the human body. People, animals and plants are made up of chemical elements. Suppose there is a method that can decompose the human body to the basic composition, we will collect a few dozen liters of oxygen, hydrogen and nitrogen gas; a pile of coal ( carbon ), calcium, salt; several inorganic elements such as sulfur, phosphorous, metals such as iron, magnesium, sodium and more than a dozen other miscellaneous elements.

If evaluated according to commercial standards, all of these chemical elements are almost invalid. However, nature has used the method that we now call " nanotechnology " to turn immovable, senseless elements into a conscious, fertile, thinking creature. know how to walk, know how to crawl, know how to swim, know happiness, know how to sulk, know how to be happy . The commercial value of this intelligent creature is priceless!

"There are lots of vacancies below"

Dr. Richard Feynman (1918 - 1988, Nobel Prize in physics 1965) is a physical genius. In 1959, he had an ingenious prediction of nanotechnology in a talk titled "There is plenty of room in the bottom" (There's plenty of room at the bottom) at the California Institute of Technology (Caltech, USA). . He is a man with humor, idleness, love to play, and apple. When he was born, he was a musician of Samba, who liked to mix with his students. This is also reflected in the title of the talk. He plays words; " bottom " means the butt, the table, also means the bottom, the end. " Miệt dưới " in Vietnamese has two meanings.

Read through the title of the talk, many people are bewildered, but Mr. Feynman is not joking, he talks seriously. He questioned how to store all 24 Britannica encyclopedias with a total of 25,000 pages on a needle with a diameter of 1.5mm. According to Feynman, this possibility exists. The listener was bewildered, because in 1959 the most advanced electronic device was a vacuum-controlled television that each time a few minutes had to wait for new images to appear. At the same time, the owner of Sony ( Japan ), Morita Akio, has launched a battery-powered transistor radio market. From a huge radio with a vacuum tube to a portable radio is a spectacular achievement of contemporary technology. Is Feynman's problem a big deal ?! Feynman assured the audience that he did not " manipulate ", all he said was feasible, in accordance with and within the limits of the laws of physics. So, how did Feynman convince his audience?

G.Binning (right) and H.Rohrer won the 1986 Nobel Prize for tunnel scanning microscopy techniques (Photo: Nanoworld)

He explained with a very simple number. Want to put 25,000 pages on the face of the needle, we only need to shrink 25,000 times the entire encyclopedia. It means that the printed words must also be reduced to 25,000 times. In letters, the dot on the beginning of the " i " is the smallest symbol. After scaling 25,000 times, the dot still has a size of 1,000 atoms. The number of 1,000 atoms is still very large and gives a lot of options for people to manipulate by some physical method. Feynman continued his thesis. He estimated that there are 24 million books in libraries around the world. If all is reduced to 25,000 times, the entire book of human expression knowledge on the earth will be " printed " only on 35 A4 pages! Feynman also talked about the ability to make molecular wires and electronic components like transistors on a molecular scale. He spoke of a large tool for making smaller and smaller tools to help people move, manipulate and control atoms and molecules at their disposal.

The purpose of Feynman's talk is not only to miniaturization but also to outline the possibility of forming a new technology in which people can move and overlap types of atoms and molecules. to design an extremely small device at the microscopic level or to design an instrument right from its molecular structure. That method in the 21st century is called " nanotechnology " with how to design each atom " bottom up ".

Nanotechnology has revolutionized the thinking of designing all materials from the molecular level.

Nobel Prize-winning physicist Richard Feynman since 1959 has predicted nanotechnology.

In fact, miniature techniques or " top-down " methods have been the backbone of building and developing the electronics industry for more than 50 years. The transistor is a key component in the circuits of electronic devices. It is a " soul " from a humble computer to a complex computer. The " top-down " method has been applied to shrink the transistor with an initial width of several centimeters at the time of the invention (1947) until today it reaches the nanometer; a few million times smaller.

'Hundred listen, one hundred and one touch'

The human body is a nano product

After Feynman's famous and convincing talk, thousands of scientists over the past 50 years have studied and collected knowledge, created many methods, groped into the microscopic world to "enter. cave catch tiger cubs "! The " tiger " here is the atoms and molecules that scientists want to see, want to capture, move them intentionally and eventually establish properties for an application.

Since the concept of atoms in natural science was born more than 100 years ago, it has been confirmed that atoms are the smallest element of all things, but in reality no one has ever seen them until the year. 1981. This year, two researchers from IBM, G.Binning and H.Rohrer, announced to the world that they had ' seen ' atoms with tunnel scanning microscopes (scanning tunnelling microscope - STM) was invented by the two men and won the Nobel Prize for this achievement.

"Hundred listening is not the same" , but people are still not satisfied. The curiosity of humans urged the right hands to work, because " hundred saw no more than a touch "! In addition to seeing atoms, STM also gives the ability to move atoms. In 1990, D. Eigler and E. Schweizer were also at IBM for the first time using STM probes to move each atomic unit at their disposal. Feynman's prediction in 1959 is now a reality. The experiments of Eigler and Schweizer were carried out in vacuum and extremely low temperatures (-270 ^o C). They moved 35 xenon atoms to create three " IBM " letters. The width of these three letters is only 3 nanometers. This is the smallest alphabet of humanity!

Atomic movement is the simplest, but with the current technology still very difficult. So pulling two atoms together into molecules and superimposed the molecules together creates an engine or a super-small tool like nature has done is difficult if not paranoid at the time. current point.

Dr. Truong Van Tan (France) - According to Saigon marketing