A nanometer (nm) is one-billionth of a meter (1/1,000,000,000m), a unit of measurement used to gauge the size of extremely small objects. The smallest structure of matter is the atom, measuring about 0.1 nm; a molecule, which is a collection of many atoms, measures around 1 nm; bacteria are approximately 50 nm; red blood cells are about 10,000 nm; sperm cells measure around 25,000 nm; a human hair is about 100,000 nm; the tip of a pin is 1 million nm; and the height of a human is about 2 billion nm.
Nanoscience and nanotechnology is a field that investigates and explores the properties of ultra-small materials to manipulate and stack these materials to build larger objects. The method of building from small to larger and even larger objects is referred to as the “bottom-up method.” The emergence of nanoscience and nanotechnology is revolutionizing the way we think and design all kinds of materials, from therapeutic pharmaceuticals to electronic components, with predetermined properties at the molecular level.
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Nanotechnology is just beginning to take its first steps. (Image: SGTT) |
A product of nanotechnology is the human body. Humans, animals, and plants are composed of chemical elements. Suppose there were a method to decompose the human body down to its fundamental components, we would collect several liters of oxygen, hydrogen, and nitrogen gas; a pile of carbon, calcium, salts; a few handfuls of inorganic elements like sulfur, phosphorus, metals such as iron, magnesium, sodium, and more than a dozen other miscellaneous elements.
If assessed commercially, all these chemical elements would have almost no value. However, nature has known how to use what we now call “nanotechnology” to transform these inert, lifeless elements into a conscious being capable of reproduction, thinking, walking, crawling, swimming, experiencing joy, sadness, anger, and love… The commercial value of this intelligent organism is priceless!
“There’s Plenty of Room at the Bottom”
Dr. Richard Feynman (1918 – 1988, Nobel Prize in Physics 1965) was a genius in physics. In 1959, he made a brilliant prediction about nanotechnology in a talk titled “There’s Plenty of Room at the Bottom” at the California Institute of Technology (Caltech, USA). He was humorous, down-to-earth, and loved to joke around with his students. This is reflected in the title of his talk. He played with words; “bottom” means the buttocks, the base, and also refers to the bottom or depths. “Miệt dưới” in Vietnamese encompasses both meanings.
Reading the title of the talk, many people were confused, but Feynman was not joking; he was serious. He posed the question of how to fit the entire 24 volumes of the Britannica Encyclopedia, totaling 25,000 pages, on the tip of a pin with a diameter of 1.5 mm. According to Feynman, this possibility exists. The audience was perplexed, as in 1959, the most advanced electronic device was a vacuum tube-controlled television that took several minutes to display an image after being turned on. At the same time, the founder of Sony (Japan), Akio Morita, had just launched a pocket-sized transistor radio. The leap from a bulky vacuum tube radio to a pocket radio was a remarkable achievement of contemporary technology. Was Feynman’s proposal something unbelievable?! He reassured his listeners that he was not “pulling their leg“; everything he said was feasible and within the bounds of physical laws. So how did Feynman convince his audience?
G. Binning (right) and H. Rohrer won the 1986 Nobel Prize for their development of scanning tunneling microscopy (Image: Nanoworld)
He explained with very simple numbers. To place 25,000 pages on the surface of the tip of a pin, we only need to shrink the entire encyclopedia by 25,000 times. This means that the printed letters also need to be reduced by 25,000 times. Among the letters, the dot on the letter “i” is the smallest symbol. After shrinking it 25,000 times, the dot would still be the size of a collection of 1,000 atoms. The number of 1,000 atoms is still quite large and offers many choices for humans to manipulate using some physical method. Feynman continued his argument. He estimated there are about 24 million books in libraries worldwide. If all were shrunk 25,000 times, the total written knowledge of humanity on Earth would be “printed” on just 35 A4 pages! Feynman also mentioned the possibility of creating molecular wires and electronic components like transistors at the molecular scale. He spoke about large tools creating smaller and smaller tools to enable humans to move, manipulate, and control atoms and molecules as they wish.
The purpose of Feynman’s talk was not only to discuss miniaturization techniques but also to outline the potential for a new technology where humans could move and stack various atoms and molecules to design extremely small devices at the microscopic scale or even design a device right from its molecular structure. This method, in the 21st century, is referred to as “nanotechnology” with an atom-by-atom design approach “from the bottom up.”
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Nanotechnology has revolutionized the design thinking of all materials at the molecular level. | Nobel laureate physicist Richard Feynman predicted nanotechnology back in 1959. |
In fact, miniaturization techniques or the “top-down method” have been the backbone of building and developing the electronics industry for over 50 years. Transistors are a key component in the circuitry of electronic devices. They are the “soul” of everything from humble handheld computers to complex supercomputers. The “top-down method” has been applied to miniaturize transistors, originally about a few centimeters in size at the time of their invention (1947), to nanometer scale today; several million times smaller.
“Seeing is Believing”
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The human body is a nano product |
Since Feynman’s famous and persuasive talk, thousands of scientists over the past 50 years have researched, gathered knowledge, and invented numerous methods, exploring the ultra-small world to “go into the tiger’s den and catch a tiger cub!” Here, the “tiger cub” refers to the atoms and molecules that scientists want to see, capture, and move according to their intentions, ultimately establishing properties for specific applications.
Since the concept of the atom was introduced in natural science over 100 years ago, it has been confirmed that the atom is the smallest particle of all things, but no one had actually seen one until 1981. In that year, two researchers from IBM, G. Binning and H. Rohrer, announced to the world that they had “seen” atoms using the scanning tunneling microscope (STM) they invented, for which they won the Nobel Prize.
“Seeing is believing,” but humans were still not satisfied. Their curiosity compelled them to act, for “seeing is not enough, one must also touch“! Besides seeing atoms, STM also allows for the movement of atoms. In 1990, D. Eigler and E. Schweizer, also at IBM, first used the STM probe to move individual atoms at will. Feynman’s prediction from 1959 has now come true. The experiment conducted by Eigler and Schweizer was performed in a vacuum at extremely low temperatures (-270oC). They moved 35 xenon atoms to create the letters “IBM.” The width of these three letters was only 3 nanometers. This is the smallest lettering ever created by humankind!
Moving atoms is the simplest task, yet it is still very challenging with current technology. Therefore, pulling two atoms together to form a molecule and stacking molecules to create a motor or a super small tool, as nature has done, remains a difficult, if not impossible, task at this time.
Dr. Truong Van Tan (France) – According to Saigon Marketing
