#microelectromechanical systems

Development of MEMS sensor chip equipped with ultra-high quality diamond cantilevers

A NIMS-led research group succeeded in developing a high-quality diamond cantilever with among the highest quality (Q) factor values at room temperature ever achieved. The group also succeeded for the first time in the world in developing a single crystal diamond microelectromechanical systems (MEMS) sensor chip that can be actuated and sensed by electrical signals. These achievements may popularize research on diamond MEMS with significantly higher sensitivity and greater reliability than existing silicon MEMS.

In MEMS sensors, microscopic cantilevers (projecting beams fixed at only one end) and electronic circuits are integrated on a single substrate. They have been used in gas sensors, mass analyzers and scanning microscope probes. For practical application in a wider variety of fields, including disaster prevention and medicine, they require greater sensitivity and reliability.

The elastic constant and mechanical constant of diamond are among the highest of any material, making it promising for use in the development of highly reliable and sensitive MEMS sensors. However, three-dimensional microfabrication of diamond is difficult due to its mechanical hardness. The research group developed a "smart cut" fabrication method that enabled microprocessing of diamond using ion beams and succeeded in fabricating a single crystal diamond cantilever in 2010. However, the quality factor of the diamond cantilever was similar to that of existing silicon cantilevers because of the presence of surface defects.

MEMS chips get metalenses

Combining metasurface lenses with MEMS technology could add high-speed scanning and enhance focusing capability of optical systems

Lens technologies have advanced across all scales, from digital cameras and high bandwidth in fiber optics to the LIGO lab instruments. Now, a new lens technology that could be produced using standard computer-chip technology is emerging and could replace the bulky layers and complex geometries of traditional curved lenses.

Flat lenses, unlike their traditional counterparts, are relatively lightweight, based on optical nanomaterials known as metasurfaces. When the subwavelength nanostructures of a metasurface form certain repeated patterns, they mimic the complex curvatures that refract light, but with less bulk and an improved ability to focus light with reduced distortion. However, most of these nanostructured devices are static, which limits their functionality.

Federico Capasso, an applied physicist at Harvard University who pioneered metalens technology, and Daniel Lopez, group leader of nanofabrication and devices at Argonne National Laboratory and an early developer of microelectromechanical systems (MEMS), brainstormed about adding motion capabilities like fast scanning and beam steering to metalenses for new applications.

Capasso and Lopez developed a device that integrates mid-infrared spectrum metalenses onto MEMS. The researchers report their findings this week in APL Photonics, from AIP Publishing.

New approach to measuring stickiness could aid micro-device design

Brown University engineers have devised a new method of measuring the stickiness of micro-scale surfaces. The technique, described in Proceedings of the Royal Society A, could be useful in designing and building micro-electro-mechanical systems (MEMS), devices with microscopic moving parts.

At the scale of bridges or buildings, the most important force that engineered structures need to deal with is gravity. But at the scale of MEMS—devices like the tiny accelerometers used in smartphones and Fitbits—the relative importance of gravity decreases, and adhesive forces become more important.

"The main thing that matters at the microscale is what sticks to what," said Haneesh Kesari, an assistant professor in Brown's School of Engineering and coauthor of the new research. "If you have parts of your device sticking together that shouldn't be, it's not going to work. So in order to design MEMS devices, it helps to have a good way of measuring adhesion in the materials we use."

That's what Kesari and two Brown graduate students, Wenqiang Fang and Joyce Mok, looked to accomplish with this new research. Specifically, they wanted to measure a quantity known as "work of adhesion," which roughly translates into the amount of energy required to separate a unit area of two adhered surfaces.

Piezoelectrics stretch their potential with a method for flexible sticking

Piezoelectric materials are used for applications ranging from the spark igniter in barbeque grills to the transducers needed by medical ultrasound imaging. Thin-film piezoelectrics, with dimensions on the scale of micrometers or smaller, offer potential for new applications where smaller dimensions or a lower voltage operation are required.

Researchers at Pennsylvania State University have demonstrated a new technique for making piezoelectric microelectromechanical systems (MEMS) by connecting a sample of lead zirconate titanate (PZT) piezoelectric thin films to flexible polymer substrates. Doctoral candidate Tianning Liu and her co-authors report their results this week in the Journal of Applied Physics.

"There's a rich history of work on piezoelectric thin films, but films on rigid substrates have limitations that come from the substrate," said Thomas N. Jackson, a professor at Penn State and one of the paper's authors. "This work opens up new areas for thin-film piezoelectrics that reduce the dependence on the substrate."

The researchers grew polycrystalline PZT thin films on a silicon substrate with a zinc oxide release layer, to which they added a thin layer of polyimide. They then used acetic acid to etch away the zinc oxide, releasing the 1-micrometer thick PZT film with the polyimide layer from the silicon substrate. The PZT film on polyimide is flexible while possessing enhanced material properties compared to the films grown on rigid substrates.

Amorphous metallic glass for high-sensitivity MEMS microphones

Advanced microphones using microelectromechanical systems (MEMS) are capable of supporting new user interactions with "smart" devices, like chatting with Apple's Siri, or Amazon's Alexa. The key to achieving the high sensitivity desired for these microphones, you might be surprised to learn, is tied to the "admittance" or "compliance" of its membrane components.

Polysilicon is the material most commonly used as a membrane for microphone devices today. But, in general, single-crystal and polycrystalline-silicon-based devices are brittle and prone to fractures that can cause interior defects during the fabrication processes. This has lead researchers to search for a replacement material.

During the AVS 64th International Symposium & Exhibition, being held Oct. 29-Nov. 3, 2017, in Tampa, Florida, researchers from WPI-Advanced Institute for Materials Research/Micro System Integration Center at Tohoku University, in Japan, will present their work with a potential replacement material that shows promise for MEMS microphones: amorphous metallic glass.

"One of the most important specifications to evaluate these devices is signal-to-noise ratio (SNR)," said Mai Phuong Nguyen, assistant professor at Tohuku University. "SNR is a good indicator of the minimum sound level that a microphone can detect within a quiet environment."

Implantable microrobots: Innovative manufacturing platform makes intricate biocompatible micromachines

A team of researchers led by Biomedical Engineering Professor Sam Sia at Columbia Engineering has developed a way to manufacture microscale-sized machines from biomaterials that can safely be implanted in the body. Working with hydrogels, which are biocompatible materials that engineers have been studying for decades, Sia has invented a new technique that stacks the soft material in layers to make devices that have three-dimensional, freely moving parts. The study, published online January 4, 2017, in Science Robotics, demonstrates a fast manufacturing method Sia calls "implantable microelectromechanical systems" (iMEMS).

By exploiting the unique mechanical properties of hydrogels, the researchers developed a "locking mechanism" for precise actuation and movement of freely moving parts, which can provide functions such as valves, manifolds, rotors, pumps, and drug delivery. They were able to tune the biomaterials within a wide range of mechanical and diffusive properties and to control them after implantation without a sustained power supply such as a toxic battery. They then tested the "payload" delivery in a bone cancer model and found that the triggering of release of doxorubicin from the device over 10 days showed high treatment efficacy and low toxicity, at 1/10 of the standard systemic chemotherapy dose.

The global MEMS Pressure Sensors Market is estimated to be valued at US$ 2226.91 million in 2022 and is expected to exhibit a CAGR of 6.14% over the forecast period 2022-2030, as highlighted in a new report published by Coherent Market Insights.

A) Market Overview:

MEMS pressure sensors are micro-electromechanical systems that measure the pressure of gases or liquids. These sensors offer numerous advantages such as small size, low cost, high reliability, and accuracy. The increasing demand for miniaturized and smart devices in various industries such as automotive, healthcare, consumer electronics, and industrial applications is driving the growth of the MEMS pressure sensors market. These sensors are used in applications such as tire pressure monitoring systems, medical devices, industrial process control systems, and HVAC systems, among others.

B) Market Key Trends:

One key trend driving the global MEMS Pressure Sensors market is the increasing adoption of IoT (Internet of Things) devices. With the rise of IoT technology, there has been a surge in the number of connected devices, which has led to a higher demand for MEMS pressure sensors. These sensors play a crucial role in measuring and monitoring pressure in IoT devices, enabling real-time data collection and analysis. For example, in automotive applications, MEMS pressure sensors are used in tire pressure monitoring systems to ensure optimal performance and safety.

C) PEST Analysis:

Political: Government regulations and policies regarding the use of MEMS pressure sensors in certain industries can impact the market growth.

Economic: Economic factors such as GDP growth, disposable income, and investment in R&D activities can influence the demand for MEMS pressure sensors.

Social: Increasing awareness about the benefits of MEMS pressure sensors in improving efficiency and safety is driving their adoption in various industries.

Technological: Advancements in MEMS technology, such as the integration of multiple sensors and wireless connectivity, are fueling market growth by enabling the development of innovative products.

D) Key Takeaways:

Paragraph 1: The global MEMS pressure sensors market is expected to witness high growth, exhibiting a CAGR of 6.14% over the forecast period, due to the increasing demand for miniaturized and smart devices. These sensors offer advantages such as small size, low cost, and high reliability, making them essential components in various industries.

Paragraph 2: In terms of regional analysis, North America is expected to dominate the MEMS pressure sensors market due to the presence of key players and the growing adoption of IoT devices in the region. Asia Pacific is anticipated to be the fastest-growing region, primarily driven by the increasing demand for consumer electronics and automotive applications.

Paragraph 3: Key players operating in the global MEMS pressure sensors market include First Sensor AG, Bosch Sensortec GmbH, Honeywell International Inc., Murata Manufacturing Co. Ltd., ROHM Co. Ltd., Amphenol Corporation, InvenSense Inc. (TDK Corporation), Sensata Technologies Inc., NXP Semiconductors NV (Freescale), Goertek Inc., TE Connectivity Ltd., STMicroelectronics NV, Infineon Technologies AG, Omron Corporation, and Alps Alpine Co. Ltd. These players focus on strategic partnerships, collaborations, and product innovations to strengthen their market position.