The development of any science and technology is often ups and downs, with highs and lows. Technology needs time to prove, but also the accumulation of industry, MEMS technology is a technology that has experienced ups and downs. Since the 1970s, MEMS has evolved from sensor technology, gradually forming a micro-electromechanical system with an intelligent “brain”, and its application has gradually expanded from military to civilian use. Today, MEMS technology is “ubiquitous” , becoming a standard-grade semiconductor technology.

For the popularization and application of MEMS technology, Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, is very optimistic about its prospects. Because MEMS have good cost performance, high performance, low power consumption, and small size, the size of MEMS systems can be in millimeters or even micrometers and nanometers. These features are suitable for applications such as medical, industrial, automotive, aviation, and location services. At ADI China’s 25th Anniversary Media Technology Day, Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, explained ADI’s ubiquitous MEMS technology and the application trend of MEMS sensing technology. ADI’s MEMS products have been widely used. .

Zhao Yanhui, Director of ADI’s Asia Pacific MEMS Product Line, photo courtesy of ADI

MEMS technology is “everywhere”

MEMS is a system that integrates microsensors, signal processing, integrated devices, and communications. MEMS accelerometers, microvibrators, MEMS optical sensors, pressure sensors, and gyroscopes all incorporate MEMS technology. Because MEMS is a comprehensive technology that integrates many disciplines such as electronics, optics, materials, mechanics, chemistry, and mechanics, there are many problems in the process of advancement. ADI’s strong technical strength and innovation are exactly these customers. key to the puzzle. Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, said that MEMS technology is ubiquitous, and we come into contact with many MEMS-related products every day. For example, there are many MEMS accelerators in mobile phones. Its function is to perform screen rotation processing. When entering the tunnel, MEMS technology can guide the car, and the airbag in the car also uses MEMS to control the body stability, etc., automatic driving, mobile phone positioning, vehicle supervision, precision agriculture, urban parking, surveying and mapping, airport platform, bridge monitoring , port loading and unloading, slope monitoring application scenarios are the most commonly used MEMS technology.

The MEMS system has a very important application in the national economy. With the advancement of intelligent products, MEMS also has its own advantages in intelligence. What are the advantages of ADI’s MEMS technology? In this regard, Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line Said that with the increasing demand for massive positioning, satellite navigation is inseparable from inertial navigation. my country’s Beidou satellites will complete the basic global layout in 2020, and domestic Beidou can be used to achieve high-precision location services. ADI’s technology will be more widely used, and inertial navigation is required to connect massive location needs to the network. Nowadays, the minimum navigation accuracy of Beidou is 2.5 to 5 meters. For many applications, such accuracy is far from enough. At this time, it is necessary to use the assistance of MEMS technology to improve the navigation accuracy of satellites. Satellite navigation is very practical, but it has an inherent disadvantage, that is, the signal passing through the troposphere has a refraction error. Such positioning accuracy is not accurate enough. For vehicle applications, such a large error is not allowed. When the car enters a tunnel or parking lot and the satellite signal is interrupted, the car can only use inertial navigation, which is MEMS technology.

Unmanned driving is one of the most popular applications at present, and driving positioning is a technology that must be configured for unmanned driving. In complex driving environments, MEMS technology and satellite navigation complement each other. MEMS inertial sensors include low-precision inertial sensors, intermediate-level inertial sensors, and high-precision inertial sensors, with different application scenarios. Unmanned vehicles generally use low-to-medium-level inertial sensors, which are characterized by high update frequency. The inertial sensor is a high-frequency sensor that detects acceleration and rotational motion. After processing the inertial sensor data, the displacement and rotation information of the vehicle can be obtained in real time. However, the inertial sensor itself also has problems such as deviation and noise that affect the results. Inertial sensors have sensors, signal conditioning, various temperature compensation calibrations, etc. ADI’s MEMS technology incorporates these things. In November 2019, ADI just released a device-scale inertial sensor. “What we want to do is high-precision positioning, and at the same time, we will do mass market. You may have requirements for this kind of cost-effectiveness. We hope that the performance will be good, and we will be able to provide long-term positioning and accuracy. Now we need small size and low cost. ADI’s S1650X series inertial The sensor is aimed at this market.” Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, told the media editor.

ADI has very good detection of gravitational waves, various ADCs, processors, and the company provides customers with a complete solution. ADI’s inertial sensor uses a core sensor, which has very good vibration suppression characteristics. For example, in a car, it can detect the rotation angle of the car and the deviation of the car’s heading. There are many ADI inertial sensors on agricultural drones. ADI uses a differential structure internally, which achieves very good vibration suppression characteristics, including applications such as drones, agricultural tractors, and automatic driving, which can reduce product bumps.

The current trend of sensors is smart sensors, and many sensors have many integrated smart nodes, which requires smaller, low-cost, low-power MEMS sensors, which are essential in machine physical examination, prediction, and information processing. of. To improve the measurement accuracy of the sensor, the sensor must be sensitive enough, and the noise density is very low. Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, mentioned that the current ADXL100X series has just achieved such a technological breakthrough. The frequency can reach 45KHz, the effective bandwidth can reach 30KHz, and the noise can reach 25dB, which is far ahead in the industry.

In bridge applications, MEMS sensors have very low frequencies, which are important for monitoring, and piezoelectric sensors are difficult to achieve. ADI has a very deep accumulation of system technology, which can integrate MEMS sensors into various signal conditioning, and provide a complete vibration solution to meet customer needs. Another application of MEMS sensors is earthquake early warning. In the past, earthquake monitoring equipment was arranged in low density. Now, big data is used to realize early warning. Using low-density professional seismic equipment and high-density auxiliary seismic equipment, early warning is achieved through MEMS accelerometers. Accelerometers must have low noise and low power consumption.

Earthquakes have different levels. The lower the level, the smaller the vibration amplitude. It is very intuitive that the vibration amplitude is small and there must be low enough noise to distinguish the small enough level. There are also a large number of spots that are powered by batteries. You don’t know when the earthquake will happen, you can only keep it working, so the sensor must have enough low power consumption. If these two are considered together, ADXL355 Definitely the first choice in the market. In the gas meter, it has been successfully applied by customers. When a strong earthquake of magnitude 5 is detected, the gas meter can be automatically cut off to prevent the occurrence of secondary disasters.

Finally, Zhao Yanhui, director of ADI’s Asia-Pacific MEMS product line, said that ADI is the first company in the industry to commercialize MEMS technology. It started in 1987. In 1991, it replaced the traditional bubble with MEMS. In 2019, ADI invented CLHP again. Inertial sensor. With the development of Beidou and 5G industries, a large number of location services will make ADI’s MEMS technology shine.