The Development Status of Micro-machining Technology

In 1959, Richard P Feynman (the winner of the Nobel Prize in Physics in 1965) proposed the idea of ​​micromachines. In 1962, the first silicon miniature pressure sensor came out, and the climate developed micro-machines such as gears, gear pumps, pneumatic turbines and couplings with a size of 50-500μm. In 1965, Stanford University developed a silicon brain electrode probe, and later succeeded in scanning tunneling microscopes and miniature sensors. In 1987, the University of California at Berkeley developed a silicon micro-electrostatic machine with a rotor diameter of 60 to 12 μm, showing the potential of using silicon micro-machining technology to manufacture small movable structures and compatible with integrated circuits to manufacture tiny systems.
Micromachines have been highly valued by government departments, business circles, universities and research institutions abroad. In the late 1980s, 15 scientists from MIT, Berkeley, Stanford\AT&T and the United States put forward a national proposal on “Small Machines, Big Opportunities: A Report on Emerging Fields-Microdynamics”, claiming that “Due to microdynamics The urgency of (microsystems) in the United States should take the lead in the competition with other countries in such a new and important technological field.” It is recommended that the central fiscal advance should be US$50 million for five years. Invest and regard aerospace, information and MEMS as the three major points of technological development. NASA invested 100 million US dollars to develop the “Discover microsatellite”.

The National Science Foundation took MEMS as a newly emerging research field and formulated a plan to fund research on micro-electromechanical systems. Since 1998, it has funded MIT. Eight universities including the University of California and Bell Laboratories are engaged in research and development in this field, with annual funding ranging from 1 million and 2 million to 5 million US dollars in 1993. The “Technical Plan of the US Department of Defense” report released in 1994 listed MEMS as a key technology project. The US Department of Defense Advanced Research Projects Agency actively leads and supports MEMS research and military applications. A MEMS standard process line has been established to promote the research and development of new components/devices. The American industry is mainly devoted to the research of sensors, displacement sensors, strain gauges and accelerometers in related fields.

Many institutions have participated in the research of micro-mechanical systems, such as Cornell University, Stanford University, University of California, Berkeley, University of Michigan, University of Wisconsin, Old Lenz Demore National Research, etc. The Berkeley Sensor and Actuator Center (BSAC) of the University of California, after receiving 15 million yuan funding from the Department of Defense and more than a dozen companies, established an ultra-clean laboratory of 1115 m2 for research and development of MEMS.

In 1991, the Ministry of International Trade and Industry of Japan started a 10-year, large-scale research project costing 25 billion yen to develop two prototypes, one for medical treatment, entering the human body for diagnosis and microsurgery, and the other for industrial use. , Carry out repairs to tiny cracks in aircraft engines and atomic energy equipment. Dozens of units including the University of Tsukuba, Tokyo Institute of Technology, Tohoku University, Waseda University and Fujitsu Research Institute participated in the program.

European industrialized countries have also successively made key investments in the research and development of micro-systems. Germany started the micro-processing 10-year plan project in 1988. The Ministry of Science and Technology allocated 40,000 marks to support the research of the “micro-system plan” from 1990 to 1993. The microsystem is listed as the focus of scientific and technological development at the beginning of the century. The LIGA process pioneered by Germany has provided new technical means for the development of MEMS and has become the preferred process for the production of three-dimensional structures. The 70 million francs “microsystem and technology” project launched by France in 1993.

The European Community formed the “Multifunctional Microsystem Research Network NEXUS” to jointly coordinate the research of 46 research institutes. Switzerland has also invested in the development of MEMS on the basis of its traditional watchmaking industry and small precision machinery industry. In 1992, the investment was 10 million US dollars. The British government has also formulated a nanoscience plan. 8 projects are listed for research and development in the fields of mechanics, optics and electronics. In order to strengthen Europe’s power to develop MEMS, some European companies have formed MEMS development groups.

At present, a large number of micro-machines or micro-systems have been studied. For example, micro-tweezers with a tip diameter of 5μm can hold a red blood cell, and a micro-pump with a size of 7mm×7mm×2mm can reach a flow rate of 250μl/min. A robotic butterfly flying in a magnetic field, and a miniature inertial unit (MIMU) that integrates a miniature speedometer, a miniature gyroscope, and a signal processing system. Germany created the LIGA process to make cantilever beams, actuators, micro pumps, micro nozzles, humidity, flow sensors and various optical devices.

The California Institute of Technology in the United States glues a considerable number of 1mm microbeams on the aircraft wing surface to control the bending angle to affect the aerodynamic characteristics of the aircraft. Mass-produced silicon accelerometers in the United States integrate miniature sensors (mechanical parts) and integrated circuits (electrical signal sources, amplifiers, signal processing and positive detection circuits, etc.) on a silicon chip within a range of 3mm x 3mm. The micro lathe of several centimeters developed in Japan can process micro shafts with an accuracy of 1.5μm.