It's a portrait of jun ho. If zhang wuchang's smart system is compared to the human, the sensor is the sensor of the human sense. Different types of sensors, sense the surrounding environment and transmit the data to the system for calculation, real-time analysis, judgement and response. With the deepening of digital intelligence, the use of a wide variety of sensors has expanded considerably and has played a significant role in creating a better life for humankind. There are hundreds of sensors in a smart phone: there are ccmos image sensors for camera, there are optical sensors for detecting the dark environment, and there are geomagnetic sensors, gyroscopes for navigation ... It is on the basis of these sensors that the various applications in the cell phone work, and mobile phones become portable smart devices for integration of work, life and entertainment, bringing about a dramatic change in people's lifestyles. Visible and infrared pv sensors on wind cloud satellites can access atmospheric information day and night, predict weather with precision and have sensor work even on the moon and mars to help humans explore the mysteries of the universe. Beyond sensor sensors is the "good eye" of an information system. Like human organs such as eyes, ears and skin, it senses the surrounding environment and helps us to understand the colourful world. The difference is that sensors are more sensitive and powerful than people's senses. The information contained in an objective world is much more diverse than our senses. Infrared and uv radiation cannot be observed in human eyes, infrasound and ultrasound cannot be heard in ears, nor can they be seen in magnetic fields that are “undetected” but have a constant impact. These are information that goes beyond the sensor, and the sensor can be “percepted”. As productivity develops, humankind increasingly needs to feel the world in all its dimensions. In 1821, scientists developed the world's first sensor, the temperature sensor, using the principle that materials generate voltage due to temperature variability. Initially, people directly used the physical effects of light, heat, power, power, magnetic, etc. To prepare various sensors, which were large in size, low sensitivity and indisposable to use. In the 1970s, integrated sensors that integrated sensitive elements with signal circuits, such as thermal electromechanical sensors, the hole sensors, photo-sensitive sensors, etc., emerged. Such sensors consist of solid elements such as semiconductors, electrical media, magnetic materials, etc., and output simulated signals. Starting at the end of the last century, digital sensors developed rapidly to achieve digital signal output through the “simulation/digital” conversion module. Digital sensors are integrated into intelligent processing units that automatically capture, process and adapt work parameters to the environment, and the photo-sensitive elements in digital cameras represent the product. In general, sensors operate on the basis that the electron properties of certain substances vary according to environmental factors. For example, platinum has different resistance rates at different temperatures, with less resistance from silicon in visible light and a charge from the surface of the quartz after pressure. Use of electrical resistance and temperature correspondence can be used to create temperature sensors, adding further insulation structures to sensitive elements, and infrared sensors based on the relationship between temperature changes in sensitive components and the energy of infrared radiation. On this basis, non-contact thermometric sensors can also be created based on the relationship between target temperature and infrared radiation energy. This principle is used by the familiar thermostats used to measure body temperature. With abundant physical and chemical effects, a wide variety of powerful sensors, such as infra-red cameras that can observe objects in the night, are produced that are 1,000 times more sensitive than dog noses, “electronic noses” that can “hear” gas molecules. Numerical digitization of the foundation is the quantification of the properties of things and expresses them in numbers as abstract results. Through modern information technology, people can store, process and disseminate digital information. Sensors can convert information contained in things into telecommunications numbers and digitally express telecommunications numbers using digitally converted circuits, which are effective tools for digitization. When you take a picture or video from your mobile phone, the light-sensitive sensor converts the receiving light strength signal into a telecommunications signal, which is digitally expressed, stored, and ultimately creates images on the mobile phone screen. Digitalizes sensor-based access to information. The amount of information to be processed by digitized systems is very large and is not available either by hand or by traditional equipment alone, while the use of sensors allows real-time, efficient, accurate and rapid access, resulting in large urban data, large weather data, large medical data, large agricultural data, etc. Using a variety of sensors, people can develop a digital economy business by holding teleconferences, learning web courses, scrutinizing fees and even live delivery. The technologies involved in the digital economy, such as cloud computing, physical networking, artificial intelligence and 5g communications, are closely related to sensors. Without sensors, there is no digitization and no intelligence. Sensors are the first steps of an intelligent system, and their levels determine the level of an intelligent system and its instruments. Sensor technology has become an international front for research in the field of high-end information devices and plays an irreplaceable role in areas such as artificial intelligence, smart cities, 5g communications, aerospace and life and health. For example, a car will be equipped with more than 100 sensors, such as pressure, temperature, location, sound, light, electricity, etc., which will be processed by a computer on board to assist the driver in making judgement. Smart analysis of data reduces the difficulty of driving cars and makes them safer and better driven. Furthermore, unmanned vehicles receive real-time road information through sensors, and as soon as barriers are found, they are given in time through intelligence analysis. Buildings such as mid-city buildings, bridges and tunnels also require real-time monitoring of the security situation through sensors such as video, temperature, pressure and smoke. When data are aggregated, intelligent systems will analyse in a timely manner and extract a small amount of critical information for decision-making by users. Even in the future, human senses can become more powerful with sensors and build intelligent systems. At present, new scenarios are taking place in which sensors are moving in the direction of increasing performance and reducing costs, evolving in the direction of digitalization, intellectualization, miniaturization, green, low-carbon, wearable, etc. Among them, the development of smart sensors, soft sensors, new principles sensors is representative and is expected to shape new working lifestyles. The development of smart sensors is an important trend. Through smart sensoring techniques, sensor units and microsystems with access, storage and analysis capabilities are designed to achieve low-cost, high-precision information capture. Smart sensors are widely used in robotics, unmanned, intelligent manufacturing, motor-quantitative monitoring, etc., and can also be used to develop inert or micro-health monitors. The active blood sugar that has prevailed in recent years is a good example. Diabetes patients put soft sensors into the body without pain and the sensors measure blood sugar values every five minutes and transmit them to mobile phone applications. Patients can observe changes in blood sugar curves and regulate blood sugar in a timely manner, including through diet and exercise, and some even leave medication and insulin treatment. In addition, degradable electronic devices are being developed to better enable intelligent sensors to contribute to low-carbon and environmentally friendly lives. The development of flexible sensors is another trend. Many applications require sensors to be prepared on flexible matrix materials and to be transparent, flexible, extended, freely bent and even folded, portable and worn. Common sensor materials currently being prepared for flexible sensors include carbon-based materials (carbon black, carbon nanopipes, graphite, etc.), metal nanomaterials (metal nanolines, metal nanoparticles, etc.), high molecular polymers and protein fibres. For example, a conjunctive super-molecular polymer electrode with stretchability, resistance to to tearing and self-rehabilitation can be used to produce next generation worn and implanted flexible electronics. Combining an integrated multifunctional flexible sensor with a soft print circuit, it can be made into a “smart belt”, which can be worn in different parts of the body, allowing real-time monitoring and analysis of physiological information and helping people, especially sensory degraded groups, to understand their health status. New principles sensors are also emerging. In the field of basic research, new patterns are being discovered and new scientific cognitive sensors are being used. At the same time, technological advances have introduced new requirements for basic research. In life, people want to improve the performance parameters of cameras, such as pixels, sensitivity, speed, etc.; in high-speed experiments, stripming cameras are needed to record information on flying seconds; in quantum communications, photons are needed that are sensitive to single photons; in space technology, detection of high-speed motion objects and cold targets is needed, etc. This requires scientists to further explore the physical world, discover new patterns of new phenomena and enhance sensor performance. With the rapid development of science and technology, new technologies for new materials are constantly being applied, and more powerful, diverse and intelligent sensors will create more new scenes for working life and help people “felt” a better life。(as a member of the chinese academy of sciences and researcher of the shanghai institute of technical physics of the chinese academy of sciences)
