As a new discipline closely related to modern science, sensing technology has also been rapidly developed. It has been used more and more extensively in disciplines such as industrial automation measurement and detection technology, aerospace technology military engineering and medical diagnosis. At the same time, Development also has a facilitating role. With the technological advances of MEMS, laser technology and high-tech materials, the development of sensors presents diversified trends. Some use biological materials to simulate human skin and innovate the sensor's sense of touch. Some use MEMS technology to develop miniature intelligent sensors, thus Is conducive to the integration of complex systems; some use of laser technology to create high-precision laser radar, which will help the system to perceive the surrounding real-time obstacles and the environment and so on. By definition, an intelligent sensor is a sensor that has information processing capabilities. Smart sensor with a microprocessor, with the ability to collect, process, exchange information, the sensor is integrated with the microprocessor product. The sensory system of the general intelligent robot is made up of a plurality of sensors, the information collected needs the computer to deal with, and the intellectual sensor can disperse the information, thus reduce the cost. Compared with the general sensor, the intelligent sensor has the following three advantages: through software technology can achieve high-precision information acquisition, and low cost; has a certain degree of programming automation; versatility. In summary, the main functions of smart sensors are: (1) With self zero, self calibration, self calibration function; (2) with automatic compensation function; (3) It can automatically collect data and preprocess the data; (4) can automatically test, optional range, find fault; (5) with data storage, memory and information processing functions; (6) Bidirectional communication, standardized digital output or symbol output function; (7) With judgment, decision-making processing function. Internet of Things market triggered new demand for smart sensing technology The concept of smart sensor is imported from abroad, usually defined as "with a microprocessor, with information processing capabilities of the sensor." According to the National Standard "Sensitive Components and Sensor Terminology", "sensor" is defined as a device or device that can sense the specified measurand and convert into the available output signal according to certain rules. There are usually sensitive components and conversion components. In the 1980s, the signal processing circuit (filter, amplifier, zero) with the sensor design together, the output 4 ~ 20mA current or 0 ~ 5V voltage, so that the sensor is an intelligent sensor at the time. We call it "the first generation of smart sensors." From the late 1980s to the mid-to-late 1990s, a single-chip microprocessor was embedded in the sensor to achieve temperature compensation, correction and calibration, and the analog signal was converted to a digital signal by an A / D converter. This type of sensor not only hardware, but also through the software for simple signal processing, the output is a digital signal. We call it "the second generation of smart sensors." After the concept of "Fieldbus" is put forward, new requirements are put forward on the design of the sensor, requiring full digital and open two-way communication. The exchange of measurement and control information is mainly done through the fieldbus at the bottom. The data exchange is mainly through Intranet and other networks to achieve, the software design of the sensor occupies a major position, the software through the sensor within each sensitive unit or with an external smart sensor unit together. We call it "the third generation of smart sensors." Since the 21st century, the development of small size, low cost and low power micro sensors has become possible due to MEMS technology, low-power analog and digital circuit technology, low-power radio frequency (RF) technology and sensor technology. Such micro-sensors are generally equipped with: a sensitive component (such as pressure, temperature, humidity, light, sound, magnetism, etc.) for sensing the physical quantity of the external environment, a calculation module for processing information collected by sensitive components, Radio transceiver module, a micro-sensor for a variety of operations to provide power modules. We call it "the fourth generation of smart sensors" or "intelligent networked sensors." Internet of Things (IoT) is a network that connects anything to the Internet for information exchange and communication for intelligent identification, location, tracking, monitoring and management. In short, the Internet of Things is the "Internet of Things." As an important component of the perception layer of one of the three layers of the Internet of Things, sensors transform the physical quantities, chemical quantities, and biomass in the real world into digital signals that can be processed and are the basis and premise for realizing the Internet of Things As a supporting technology, MEMS (Micro-Electro-Mechanical Technology) plays a vital role in the development of the Internet of Things.