The hottest MEMS holds the rhythm of the earth fro

2022-08-15
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MEMS: grasp the rhythm of the earth from the micro world

as shown in the figure below, this rhythm like a beating heart comes from the pressure sensor that makes up Omron sphygmomanometer, which is only 1.36 square millimeters in size. From daily life to all walks of life, sensors that detect various phenomena in nature through pressure, inertia, flow, temperature, sound and light are widely used

for example, using infrared sensors that detect the human body through body temperature can only provide lighting and air conditioning in places where there are people, thus greatly reducing the waste of power consumption. The seismic sensor can detect strong earthquakes, so as to stop the use of devices and equipment, so as to get more accurate experimental data and avoid machine failure and secondary disasters such as fire

the microphone hidden in the intelligence is actually a kind of sensor, which can detect the wide area audio from high to low, and clearly transmit the call volume and timbre through the built-in sensor

the characteristic of these sensors is very small. In the hardware with the size of only a few millimeters, there are various components such as detection devices and controllers, which can convert the detected mechanical data into electrical signals for transmission. These tiny machines are called MEMS (micro electro mechanical systems)

As a key technology in the new century, MEMS is widely used in various fields. The variety of applications related to intelligent and wearable devices is also directly related to the miniaturization and high precision of MEMS. When the intelligence is tilted, the direction of the screen will also change, and the map app used will still correctly indicate the geographical location of the user. In walking, no matter how active, intelligence can also read the user's real amount of exercise. These functions benefit from MEMS

in recent years, MEMS sensors have been able to collect "high" information, which has also attracted widespread attention. By adding height information to the location information, you can navigate the height and specific location of people in the building. Even the movement generated by going up and down the steps will be included in the real amount of movement

then, how to evaluate "height"? The key is to master the pressure difference. As we all know, the air pressure decreases with the increase of altitude. According to calculations, the pressure at the peak of Mount Everest is only 30% of the ground. Not only in high places, but also in daily life, we are often exposed to changes in air pressure caused by a very small difference in the mass of air molecules. The absolute pressure sensor can detect the small air pressure difference compared with the vacuum state

2.0mm × 2.5mm × 0.85mm, in a pen tip sized package, comes with an IC chip that can detect air pressure and achieve control effect. It can detect the pressure change of ± 0.6pa equivalent to the height of ± 5cm. The moving distance generated by people at each step up and down the steps can be accurately detected

the size of such a precise and small machine has also reached the world's cutting-edge level

through infinite combination, gather members from different fields

for those who need to meet the conditions of arbitrary design and lasting effect when opening the shape, it is more difficult than expected to manufacture a machine that can capture subtle air pressure changes in a package of only 2 square millimeters

inside the package, a silicon film (diaphragm) suspended in a vacuum environment is installed to detect the change of air pressure caused by external air entering the diaphragm. In order to improve the detection accuracy of the sensor, the silicon diaphragm must be as thin as possible, so that it can produce huge deformation after touching the subtle air pressure

in addition, in the circuit of processing electronic signals according to the changes of film shape, in order to improve the transmission accuracy, how to reduce noise has also become a major topic

even if these problems can be solved, the problem of slight deformation of the shell caused by the temperature change caused by the improved accuracy of the sensor still exists

structure diagram of absolute pressure sensor

how to create a sensor with high sensitivity and can prevent pressure other than air pressure? The members of OMRON development team had a thorough discussion from product materials to components to configuration optimization. The cover of the IC chip, the wires connecting the sensor and the IC chip, and the bonding material for fixing parts... The development team has conducted countless combination tests in order to find the best material for each part

Inoue, who was responsible for development, recalled, "Our goal is to continuously improve the performance of sensors while achieving a stable balance between production and cost. We work with members in different professional fields and functions in terms of product structure and materials, collect opinions, and constantly repeat the design and evaluation of prototypes in order to find the best configuration. When we have experienced difficulties in reaching the target configuration, the number of solutions we have tried is incredible, and we even question what we have learned so far Learn common sense and try to use materials that are considered impossible. In this way, we have also made progress and growth together with resin material manufacturers. "

however, it is not easy to make a prototype

when assembling parts less than 1 mm2, it is more important to μ M is the unit for fine adjustment, which requires the operator to have extremely high installation technology. Breaking the plasticizer 5.0~10.0 bond is Omron's sufficient experience in the MEMS field after more than 20 years

the developers said, "Omron has produced more than 1billion smart microphones, and has advanced MEMS manufacturing technology. MEMS devices are difficult to assemble, and production requires many debugging steps. However, the development of absolute pressure sensors is possible by making full use of Omron's proprietary technologies such as fine processing, packaging technology and quality inspection accumulated for many years."

the achievements enjoyed today are not only successes, but also constant failures that melt these layers

by removing other possible pressure effects, the team finally successfully developed a world-class pressure change that can detect ± 0.6pa

Omron's MEMS was born in the integration of 'inheritance of past technology' and 'innovation of new technology'. Only one and a half years after the project was launched, the world's top-level sensors were completed and released, thanks to the efforts of Omron's planning, development, technology, quality assurance and business department members. This is not the result of one person, but the result of continuous challenges. Every member wants to create new sensors and provide new value for the society

through manufacturing, MEMS will become a reality from expectation

absolute pressure sensor will be widely used in the future with its small size and high performance of detecting ± 0.6pa pressure change. It can detect people's movements and position changes when standing, sitting upright, sleeping, falling, and going up and down stairs, including accurate height changes in three-dimensional space. Making full use of the characteristics of absolute pressure sensor for action and position judgment will develop more and more applications, especially in intelligence and various wearable devices

"for example, when you don't know the floor of the lost child in the mall, or you can't determine the specific location of the survivors waiting for rescue in the building when the disaster occurs, in these cases, MEMS can accurately grasp the corresponding location in the indoor space where the GPS signal can't reach, and play a reassuring and safe role in theft prevention, child protection, and disaster relief."

in addition, MEMS can also contribute to the field of health. For example, wearable devices can measure the distance generated by going up and down steps or ramps with high accuracy, and then calculate the relevant amount of movement

we can believe that at the 2020 Tokyo Olympic Games, Omron MEMS absolute pressure sensor will be installed in the innovative 3D navigation system to guide tourists from all over the world

Mr. anda, the project manager, said, "by detecting various phenomena in nature, such as pressure, inertia, flow, temperature, sound and light, combined with Omron's sensing technology and data, and converted into valuable information, we can create more convenient and unprecedented products for mankind. All members of OMRON team will work together to turn the future from expectation to reality through MEMS."

what are your expectations for the future

the future when the expected things become a reality will be very exciting. These excitement will eventually become a reality, and OMRON will welcome this moment with its own technology

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