How to develop sensor manufacturing infrastructure is worthy of our common thinking
Editor’s note: This article comes from WeChat public account “MEMS” (ID: MEMSensor), author MEMS, the original title “Future MEMS industry Keywords: piezoelectric, event-driven, self Power supply, flexible, micro-generation factory, slightly cut.
Alissa Fitzgerald, founder of AM Fitzgerald and Associates LLC, a MEMS design and development company, said that while no one can accurately predict the future of MEMS and sensor technology, ongoing academic research is the next decade. The year provides important “clues.” New sensor structures are emerging, and sensors based on inexpensive flexible substrates (even paper) are also evolving.
In late October, at the MEMS & Sensors Executive Congress organized by SEMI, Fitzgerald said in a speech: “Academic research is the source of innovation in our industry. Today, it is a sensation in the industry. Most MEMS products come from academic research, and we hope that this model will continue.”
Fitzgerald’s cited cases include: SiTime’s oscillator is from Stanford University (relevant report: ” SiTime MEMS oscillators: SiT1552″), Cardio’s MEMS implantable pressure sensor is from Georgia Tech, and Vesper’s piezoelectric MEMS microphone originated at the University of Michigan (relevant report: “Vesper piezoelectric MEMS microphone: VM1000″ ), was acquired by TDK recently launched Chirp MEMS piezoelectric ultrasonic transducer, but also from the University of California at Berkeley and UC Davis.
Fitzgerald explains: “My magical approach is to look at the top academic research from around the world and screen it from more than 650 papers.” As for the standards that need attention, she says she is looking for “commercially feasible,” Being able to solve problems can lead to technological changes.”
Most technology is fully commercialized and requires years of dedicated development, which can cost more than $100 million. But Fitzgerald is convinced that these technologies have the potential to create new opportunities in the MEMS and sensor industries.
A change is taking place from electrostatic comb-tooth drive structures to thin-film piezoelectric structures. Because “you will be able to achieve better process consistency, higher reliability, higher yield, smaller area” Fitzgerald cites the latest two film material innovations. When the Fraunhofer Institute in Germany focused on the development of ultra-high-voltage electrical multi-layer aluminum nitride (AlN) manufacturing processes, France’s CEA-Leti has found a way to transfer the film PZT to a transparent glass substrate. A method of transparent piezoelectric structure.
Ultra-high-voltage electric multi-layer AlN manufacturing process proposed by the Fraunhofer Institute (left), transparent piezoelectric structure manufacturing process proposed by CEA-Leti (right) /Image Source: MEMS
Piezo-driven micromirrors using thin film PZT are also very interesting. Researchers at the University of Tokyo have designed a three-axis MEMS micromirror in which the two axes are mechanical and control the third axis by using the film PZT to change the curvature of the micromirror itself. Fitzgerald said: “They can make large changes in the focus distance, which is essentially 3D beam manipulation.” This technology will soon be commercialized.
Three-axis MEMS micromirrors/pictures designed by researchers at the University of Tokyo using thin film PZT: MEMS
Film-type piezoelectric materials will be used in actuators, speakers, touch and touch interfaces. “In the 1920s, it was called the era of thin film piezoelectric MEMS (Reference report:” piezoelectric device: from block type to film type -2019 Edition” , ” comparison of the piezoelectric device: from block type to film type” ). we have seen a large number of devices began using AlN and PZT materials made in my It seems that the future MEMS device driving mode from the start of the 1990s heady electrostatic comb drive steering the piezoelectric drive. “
Today, “The industry’s manufacturing process for piezoelectric filmsDemand is very urgent and I hope to get it to work as soon as possible. Fitzgerald pointed out that some work needs to be done to ensure reliability and scalability.
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Event Driven
“Hey, I just heard the sound you want!” This is the magic of event-driven sensors. When they wait for a trigger event, the power consumption is almost zero, so low power consumption, no need to change the battery frequently, clearing the main obstacles for building a large sensor network.
Fitzgerald said: “The reason I so fascinated by these sensors, because of their clever use of physics if you’re just looking for an event, you do not want to stream large amounts of data, in order to avoid excessive power consumption.” Event-driven sensors are used in a wide range of applications and can be mass-produced very quickly.
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Self-powered
After more in-depth research, Fitzgerald mentioned the Korean Institute of Advanced Science and Technology’s approach to combining solar cells with nanoimprinted polymers. (Reference Report: “semiconductor applications nanoimprinting technology trends version -2019 “)
“presence of hydrogen leads to expansion of the polymer grid.” She explained, “the grid on the solar cell changes, researchers can measure the output current of the battery, and measures the concentration of hydrogen. Researchers have developed a completely self-powered batteries, no hydrogen gas detection work before they wish to monitor for hydrogen-powered vehicles and industrial safety applications related to the hydrogen tank. “
The combination of solar cells and nanoimprinted polymers proposed by the Korea Advanced Science and Technology Research Institute / Image Source: MEMS
An example of another self-powered sensor is from Peking University, China. Researchers have developed a self-powered touch sensor that uses the triboelectric effect, which is familiar to people who wear socks and walk through the carpet and accumulate static charges from friction. Briefly, in a touch event, two polymer sheets embedded in an electrode are pressed together, and the sensor can detect the pressure and trajectory of the touch motion. Fitzgerald expects this technology to be used in security identification, smart walls, robotic touch sensors and more. However, mass production has not yet been achieved.
Self-powered touch sensor developed by Peking University using the frictional electrification effect / Image Source: MEMS
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Flexible
Fitzgerald believes that paper is the ultimate substrate for flexible sensors. At Kyushu University in Japan, researchers are using an inkjet printer to complete a gas sensor array with 36 gas sensors, the overall size of which is comparable to the size of a stamp. This flexible sensor measures the gas released by the organic decomposition process, opening the door to a variety of food safety applications. For example, the use of such sensors in food packaging materials allows consumers to obtain food freshness information. The gas sensor technology and market more information, see: Gas and Particle Sensors – 2018 Edition Again, 3D printers are starting to work. Today, 3D printers can print graphics at tens of micrometer resolution and print plastic, metal and ceramic materials. Today, there are more and more cases where 3D printing is combined with silicon nanoimprint lithography, and some emerging sensors may be “born”. According to Fitzgerald’s presentation, “We will continue to witness the emergence of low-cost semiconductor manufacturing methods. And once we start manufacturing with 3D printers, it may be done in the garage!” Today, progress in manufacturing infrastructure has slowed. Researchers use inkjet printers and 3D printers to make sensor prototypes, but they often need to use roll-to-roll printing to scale. If there is no suitable solution, paper, plastic and textile sensors can take up to ten years to achieve mass production. Fitzgerald calls everyone: “We should think together about how to develop sensor manufacturing infrastructure.” “For us, these silicon wafer manufacturing practitioners should consider how to introduce new flexible substrate technology. The emphasis here is on addition, not replacement. And once we have determined how to extend these technologies, there will be Some exciting events happen,” concluded Fitzgerald. About 3D printing, I have previously done a industry grooming.