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The Role and Significance of Metrology - Focus on Microfluidic Control Technology

With the development of science and technology and economy and the progress of society, the role and significance of measurement has become increasingly apparent. Here are a few examples:

1. Measurement and Science and Technology

As we all know, science and technology are an important foundation for human survival and development. Without science and technology, there can be no humanity today. In fact, measurement itself is an important part of science and technology. Any science and technology is to discuss, analyze, study, grasp, and use the objective laws of things; and all things are composed of certain "quantities" and are embodied by "quantity." In order to understand the quantity and to obtain it exactly, only through measurement. For example, Copernicus’ theory of the operation of celestial bodies was based on repeated observations and was established after Galileo conducted further observations with astronomical telescopes; the famous law of universal gravitation was revealed by Newton’s keen observations, and After more than a hundred years, he was confirmed by Cavendish's precision test; Einstein's theory of relativity was also verified on the basis of precise frequency measurement; Li Zhengdao and Yang Zhenyu have a parity under weak interaction. The theory of non-conservation was verified by Wu Jianxiong and others who conducted special tests at the US Bureau of Standards (Gold Standards and Technology Institute). In short, from classical Newtonian mechanics to modern quantum mechanics, various laws and theorems have been revealed, acknowledged, and established through observation, analysis, research, reasoning, and actual verification. Measurement is an important technical foundation for the above process.

The three major technological revolutions in history have fully depended on measurement, and have also promoted the development of measurement.
The first technological revolution, marked by the extensive use of steam engines as the main military symbol, led to the replacement of hand-based workshops with machine-based factories, which enabled rapid productivity growth and established the capitalist mode of production. At that time, classical mechanics and thermodynamics were important theoretical foundations for the development of social science and technology. During the development and application of steam engines, a large number of metering tests are required for steam pressure, thermal expansion coefficient, fuel combustion efficiency, and energy conversion. Mechanic measurement and thermal measurement are developed under this condition. In addition, the rise of the machinery industry has led to the further development of the measurement of geometric quantities.

The second technological revolution based on the generation and application of electricity has further promoted the development of society. Ohm's law, Faraday's law of electromagnetic induction, and Maxwell's theory of electromagnetic waves provide important theoretical foundations for the in-depth study and wide application of electromagnetic phenomena, and for the development of electromagnetic metrology and radiometry. For example, the thermoelectric effect discovered by Seebeck in 1821 laid a theoretical foundation for the birth of thermocouples; and the successful development of various thermocouples provided an important measure for temperature measurement, electrical measurement, and radio metering. The development of corresponding technologies. In order to actually measure the relative velocity of the Earth's movement, Michelson et al. used the achievements of physics to develop the Michelson interferometer, which provided an important measure for length measurement. In 1892, Michelson used Twilight (monochromatic red light) as the light source of the interferometer to measure the length of the platinum-rhodium alloy reference metre, which was stored in Paris, and obtained fairly accurate results (equal to 1 553 163.5 red wavelengths). ). Today, more than 100 years later, using various interferometers to accurately measure length is still an important method for geometrical measurement. Planck's quantification hypothesis of the state of energy indicates that when an object radiates and absorbs energy, its charged linear harmonic oscillator can exchange energy with the surrounding electromagnetic field so that it can transition from one energy level to another and the energy. The energy of a child is EE=hυ (where h is Planck's constant, υ-frequency). Einstein proposed on the basis of the Planck hypothesis that light is not only fluctuating, but also has particle properties. That is, light is a stream of particles (photons) moving at a speed c. The energy of its unit (photon) is ?E. = h 从而, which shows that photons with different frequencies have different energies. The above theory successfully explained the photoelectric effect and became the theoretical basis for the measurement of thermal radiation. At the same time, it also enabled the measurement to begin in the microscopic field from the macroscopic perspective. With the establishment and development of quantum mechanics and nuclear physics, the measurement of ionizing radiation gradually formed.

The development and application of nuclear energy and chemical industry led to the third technological revolution. During this period, science and technology and socio-economic development have accelerated. The extensive application of new technologies such as atomic energy, chemical engineering, semiconductors, computer, superconductor, laser, remote sensing, and aerospace has enabled the modernization of metrology, and the macroscopic physical reference for measurement has been gradually transformed into a vector (natural) benchmark. The establishment of the atomic frequency standard and the formation of a new definition of rice are of considerable significance. Precise measurement of frequency and length has promoted the development of modern technology. For example, the determination of the speed of light, the detection of hyperfine structures in atomic spectroscopy, and many scientific and technological fields such as navigation, aerospace, remote sensing, laser, and microelectronics are all based on the precise measurement of frequency and length.

As for the so-called fourth technological revolution that people widely talk about and pay attention to, it will cause major changes in science and technology, economy, and society. Humanity will enter the "ultra-industrial society" or "information society." At that time, non-renewable fossil fuel energy will be replaced by renewable energy such as renewable solar energy and sea tide power generation. Traditional industries such as steel, machinery, and rubber will be conquered by emerging industries such as the electronics industry, aerospace engineering, ocean engineering, and genetic engineering. and many more. The precursor of this technological revolution is microelectronics and computers, and integrated circuits can be said to be the core of the pilot. It is unthinkable to develop integrated circuits without corresponding measurement guarantees. For example, geometric parameters, physical properties of silicon single crystals, purity of ultrapure water, ultrapure gas, performance of chemical reproducts, photoresists, film thickness, dislocation dislocations, ion implantation depth, concentration, uniformity, and process monitoring Measurements and controls such as test patterns are precision measurements. At present, the development of integrated circuits in our country is still relatively backward, and the measurement cannot keep up with one of the reasons.
In short, the development of science and technology, especially the achievements of physics, has created important prerequisites for the development of metrology. At the same time, it also puts forward higher requirements for measurement and promotes the development of metrology; while the achievement of metrology has also promoted technology. development of. As Mendeleev said: "Without measurement, there is no science." Comrade Nie Rongzhen once pointed out clearly: "Technology must be developed, measurement must be preceded"; "without measurement, it is difficult to move."

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