Browse Topic: Microelectromechanical devices (MEMS)

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Fuel Film Measurement in a SI Gasoline Engine Using a Newly Developed MEMS Sensor2024-32-007104/18/2025
The previously developed capacitance sensor for detecting a liquid fuel film was modified to apply to the in-cylinder measurement. On the developed sensor surface, comb-shaped electrodes were circularly aligned. The capacitance between the electrodes varies with the liquid fuel film adhering. The capacitance variation between the electrodes on the sensor surface was converted to the frequency variation of the oscillation circuit. In the previous study, it was revealed that the frequency of the oscillation circuit varies with the variation of the liquid fuel coverage area on the sensor surface. The developed sensor was installed in the combustion chamber of the rapid compression and expansion machine, and the performance of the developed sensor was examined. Iso-octane was used as a test fuel to explore the sensor that had been developed. As a result, the adherence of the liquid fuel directly injected into the cylinder was successfully detected under the quiescent and motoring
Kuboyama, Tatsuya, Moriyoshi, Yasuo, Takayama, Satoshi, Nakabeppu, Osamu
5 Ws of 3D-Printed MEMSTBMG-4693411/02/2022
New Capabilities for Grasp-Assisting GlovesTBMG-3852202/01/2021
NASA is developing the next generation of spacesuits for future missions including the optimization of spacesuit gloves that, when coupled to a pressurized suit, tend to limit the range of motion of an astronaut’s hand to as little as 20%. Many of NASA’s future missions will be in challenging environments where hand dexterity of the astronaut will be critical for the success of the missions.
Raising the Ergonomics Bar with Smart Electric ActuatorsTBMG-3814512/01/2020
Electric linear actuators have long delivered ergonomic benefits by automating tasks that are repetitive, dirty, or dangerous. Recently, the integration of onboard intelligence into electric actuators has raised their ergonomic contribution to a new level. Smart features such as digital motor control, position feedback, synchronization, and real-time monitoring make it even easier to apply automation to improve workplace comfort, safety, and efficiency.
Process Creates Soft Actuated Objects Using Commercial Knitting MachinesTBMG-3738408/01/2020
Computationally controlled commercial knitting machines were used to create knitted objects that are actuated by tendons. New software makes it possible for the objects to emerge from the knitting machines in their desired shapes and with tendons already embedded. They can then be stuffed and the tendons attached to motors as necessary.
Soft Prosthetic Hand Feels Surroundings via Stretchable Optical WaveguidesTBMG-3720007/01/2020
Fluid-powered soft actuators have shown potential in applications such as prosthetics and orthotics due to their natural motion. Robots using these actuators require stretchable sensors that can be embedded in their bodies for sophisticated functions; however, these sensors usually rely on the electrical properties of materials and composites to measure a signal and many suffer from hysteresis, complex fabrication, environmental instability, and material incompatibility with soft actuators.
Seeables and Hearables for Fitness FeedbackTBMG-3701006/01/2020
Imagine being able to effortlessly track your fitness routine without having to look away or even think about it. Bosch Sensortec GmbH (Reutlingen/ Kusterdingen, Germany) has developed a “Light Drive” system to display data from fitness and navigation sensors onto a lens of a pair of smart eyeglasses that have transparency comparable to normal eyeglasses and that are comfortable enough to be worn all day. The data image is projected directly onto the wearer’s retina so that it is always in focus and readable despite changing ambient light conditions. You can get feedback while jogging, stair-climbing, exercising, or bike-riding.
Device Modulates Light and Amplifies Tiny SignalsTBMG-3702406/01/2020
The miniscule movement of a single particle only one-tenth the diameter of a bacterium can induce sustained vibrations in an entire mechanical device that is 50 times larger. Using the interplay among light, electrons on the surface of metals, and heat, researchers created a plasmomechanical oscillator (PMO), so named because it tightly couples plasmons — the collective oscillations of electrons at the surface of a metal nanoparticle — to the mechanical vibrations of the much larger device in which it is embedded.
Selecting Pressure Sensors for AutoclavesTBMG-3701206/01/2020
Pressure sensors are a key component in the monitoring and validation of steam temperature and other conditions in autoclaves commonly used to sterilize medical and dental equipment. Nominal conditions are around 2.1bar, 134°C (maximum pressure is about 3.8 bar/55 psi) steam from pure distilled water. Some of the requirements for pressure sensors are typical of most of today’s equipment calling for smaller form factor and cost-effective solutions. Autoclaves have additional application-specific needs for pressure sensors in that they must deliver high accuracy, be able to support elevated operating temperatures, feature high pressure capabilities, and offer harsh media compatibility.
New Graphene-Based Metasurface Capable of Independent Amplitude and Phase Control of LightTBMG-3688005/01/2020
Researchers described a new strategy of designing metamolecules that incorporates two independently controllable subwavelength meta-atoms. This two-parametric control of the metamolecule secures the complete control of both amplitude and the phase of light.
Guiding and Harnessing Transition Waves in Multi-Stable Mechanical StructuresTBMG-3685605/01/2020
A deployable structure can transition from a compact state to an expanded one. Such structures usually require rather complicated locking mechanisms to hold them in place. Today’s deployable structures aren’t always reliable or autonomous. Harnessing the domino effect, researchers have designed deployable systems that expand quickly with a small push and are stable and locked into place after deployment.
Wi-Fi-assisted Inertial Odometry (WIO) Measures Speed and Distance of Indoor MovementTBMG-3684305/01/2020
Many devices, such as smartphones, incorporate inertial measurement units (IMUs) to calculate how far a device has moved; however, IMUs suffer from large drift errors, meaning that even minor inaccuracies can quickly become exaggerated. In outdoor environments, many devices use GPS to correct their IMUs but this does not work in indoor areas where GPS signals are unreliable or nonexistent.
High-Reliability Radio Frequency MEMS SwitchTBMG-3640004/01/2020
The two types of MEMS switches — metal-to-metal contact and capacitive — are prone to failure because of sagging cantilever structures. Metal-to-metal contact switches consist of a metal transmission line and a metal bridge/cantilever that are separated by an air gap. The metal contacts in these switches are susceptible to wearing down and welding over time. Capacitive switches use both a thin insulator and an air gap between the transmission line and the bridge/cantilever, preventing the two metal structures from touching in an effort to stop the metal connects from welding together. Both of these types suffer from their reliance on metal bridge/cantilever structures that are prone to severe sagging and eventual failure through prolonged operations.
5 Ws of PAWS Smart HeadphonesTBMG-3619903/01/2020
Pedestrians who wear headphones or earbuds to listen to music, text, or talk on smartphones while walking, putting themselves at risk by tuning out the traffic around them.
High-Performance, Piezoelectric, Hybrid Synthetic Jet ActuatorsTBMG-3618103/01/2020
NASA Langley Research Center has invented three serial high-performance, piezoelectric, hybrid synthetic jet actuators to provide active flow control for current and future wing-borne vehicles in subsonic, transonic, and supersonic flow. Effective active flow control results in reduced vehicle drag and the prevention of events that can lead to catastrophic loss.
Particle Robot Works as a Cluster of Simple UnitsTBMG-3582101/01/2020
Inspired by biological cells, researchers have developed computationally simple robots that connect in large groups to move around, transport objects, and complete other tasks. This “particle robotics” system comprises many individual disc-shaped units referred to as “particles.” The particles are loosely connected by magnets around their perimeters and each unit can only do two things: expand and contract. (Each particle is about 6” in its contracted state and about 9” when expanded.) That motion, when carefully timed, allows the individual particles to push and pull one another in coordinated movement. Onboard sensors enable the cluster to gravitate toward light sources.
Microrobot Powered by Soft MusclesTBMG-3582801/01/2020
Researchers have developed a microrobot called RoboBee powered by soft artificial muscles that can crash into walls, fall onto the floor, and collide with other RoboBees without being damaged. It is the first microrobot powered by soft actuators to achieve controlled flight.
SiC-Based Microstructures for SensorsTBMG-3581501/01/2020
Innovators at NASA's Glenn Research Center have developed ultra-thin silicon carbide (SiC) microstructures that enable highly sensitive pressure sensors that are biocompatible. The novel method of fabricating these microstructures, Dopant Selective Reactive Ion Etching (DSRIE), allows for structures as thin as 2 microns to be achieved, while allowing multifunctional sensors to be fabricated on a single SiC wafer. For the first time, it is possible to batch-fabricate ultra-thin SiC diaphragms that can sense very low pressures, enabling pressure sensors that can measure sub-psi pressures. This faster process makes it easier and less costly to produce complex, advanced semiconductors that are fully functional at temperatures greater than 600 °C. This technique enables a new generation of SiC-based microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) such as accelerometers, pressure sensors, and biosensors.
WiFi-Based Technique Measures Speed and Distance of Indoor MovementTBMG-3561012/01/2019
A technique was developed that uses a combination of WiFi signals and accelerometer technology to track devices in near-real-time. The WiFi-assisted Inertial Odometry (WIO) technique uses WiFi as a velocity sensor to accurately track how far something has moved — similar to sonar but using radio waves instead of sound waves.
Battery-Free Sensor for Underwater UseTBMG-3544311/01/2019
To investigate oceans, researchers aim to build a submerged network of interconnected sensors that sends data to the surface. Supplying constant power to scores of sensors designed to stay for long durations underwater has been a major problem.
Q&A: Wearable Motion Sensors Could Save Unborn BabiesTBMG-3527510/01/2019
Negar Tavossolian is Associate Professor of Electrical and Computer Engineering at Stevens Institute of Technology, Hoboken, NJ. She led a project to develop a lightweight, non-invasive sensor to monitor fetal heart rate and motion that could sense abnormalities warning of possible stillbirths.
High-Sensitivity, Low-Noise MEMS AccelerometerTBMG-3529410/01/2019
A high-sensitivity and low-noise MEMS accelerometer was developed using multi-layer metal structures composed of multiple metal layers. The accelerometer achieves 1 μG level resolution that has been a challenging task with conventional MEMS technology. The team previously proposed a method of using gold material to downscale the proof mass size of MEMS accelerometers to less than one-tenth. In this work, they have increased the proof mass per area by employing multiple layers of gold for the MEMS structures, thereby increasing the sensitivity over 100 times and reducing noise less than one-tenth when compared with conventional accelerometers.
The Rodney Dangerfield of Automated-Driving Sensors19AVEP07_0607/01/2019
Radar and lidar get all the attention, but Inertial Measurement Units are the backbone of sensor fusion. Suppliers are scrambling to make IMUs more accurate-and much less expensive. The emerging era of highly-automated driving comes courtesy of much-vaunted sensor technology-spinning lasers, penetrating radar, sonar blips. But the sensor that gets the least respect in the technology stack could be the lynchpin for the mass roll-out of self-driving vehicles: the inertial measurement unit (IMU). “IMUs are the glue that binds everything together,” said Mike Horton, chief technology officer at Aceinna, a Boston-based company that develops sensing solutions for automotive applications. “An IMU can help bring different types of data together from GNSS (Global Navigation Satellite System), lidar and cameras to make everything consistent and smooth.”
Berman, Bradley
Sensors Expo Preview 2019TBMG-3458406/01/2019
The 2019 Sensors Expo and Conference will be held at the McEnery Convention Center, San Jose, CA from June 25 – 27. Both the expo and conference are excellent opportunities to get a good sense of important sensor trends. Among the wide variety of themes at the conference, some strike me as being very significant for the current state of the industry.
Infrared Light-Focusing PlatformTBMG-3463006/01/2019
Researchers have integrated two technologies widely used in applications such as optical communications, bio-imaging, and Light Detection and Ranging (LiDAR) systems to create a new infrared light-focusing system that combines the best features of both technologies while reducing the size of the optical system.
A Sensor that Fits Like a GloveTBMG-3458906/01/2019
We recently had a discussion with Sri Peruvemba, VP of Strategy at BeBop Sensors (Berkeley, CA), about the technology and applications for their two-dimensional fabric sensor material. I started by asking Sri about the unusual name for the company.
Snake-Inspired RobotTBMG-3457206/01/2019
Researchers have developed a new and improved snake-inspired soft robot that is faster and more precise than its predecessor.
When You Need a Machine for Breathing, You’d Better Have Accurate SensorsTBMG-3459106/01/2019
Medical ventilation technology has come far since the original iron lung was first used more than 90 years ago. Using negative pressure to ventilate, the patient was inserted into an airtight chamber looking like a prop from a Sci-Fi movie. The iron lung mimicked the physiological act of breathing. Pumps controlling airflow periodically increased and decreased air pressure within the chamber and thus indirectly in the patient’s chest. Lungs were inflated by applying negative pressure to the patient’s body and then when the pressure inside the chamber increased, it compressed the patient’s chest and forced them to exhale. But the machines were bulky and restricted a patient’s ability to move. So, when positive pressure ventilators were developed in the 1950s, the technology caught on. Patients were not restricted, and caregivers could better examine them. Modern ventilators use either a tracheal tube or mask to apply positive pressure and inflate the lung during inspiration.
Ultraminiature MEMS Sensors for Improved Patient OutcomesTBMG-3443905/01/2019
Ultraminiature sensors (<1 mm in size) enable instrumentation of medical devices in order to advance monitoring capabilities, deliver new insight into complex cardiovascular cases, and optimize targeted treatment therapies. These high-performance medically proven sensors can advance medical devices with real-time monitoring capabilities with less invasive access and more reliable results. Whether integrated directly into an existing medical device or added to a complementary delivery system or procedural accessory, ultraminiature sensors can enable new revenue streams by increasing reimbursement opportunities or adding a new component to an existing sales channel.
MEMS Switch Extends Life of CellphonesTBMG-3391703/01/2019
A new type of microelectromechanical system (MEMS) was developed that uses electrostatic levitation to provide a more robust system. All cellphones use MEMS switches for wireless communication, but traditionally there are just two electrodes. The switches open and close numerous times during just one hour, but their current lifespan is limited by the two-electrode system.
A Marriage of Light-Manipulation TechnologiesTBMG-3390003/01/2019
Researchers have, for the first time, integrated two technologies widely used in applications such as optical communications, bio-imaging, and Light Detection and Ranging (LIDAR) systems. In the collaborative effort between the U.S. Department of Energy's Argonne National Laboratory and Harvard University, researchers successfully crafted a metasurface-based lens atop a Micro-Electro-Mechanical System (MEMS) platform. The result is a new infrared light-focusing system that combines the best features of both technologies while reducing the size of the optical system.
Simulation for EveryoneTBMG-3341912/01/2018
With the computational power and software available today, numerical simulation is a real option to quickly get answers to complicated technical, scientific, and engineering questions. Not only has the hardware doubled computing capacity every 18 months or so over the past decades, but the numerical algorithms have improved at the same rate.
Inductive Non-Contact Position SensorTBMG-3340012/01/2018
The Inductive Non-Contact Position Sensor is a highly accurate sensor for motion control applications. The sensor was designed to monitor the precise movements of an optical inspection system that measured defects in space shuttle windows.
5 Ws of Spray-On AntennasTBMG-3340112/01/2018
Manufacturers and users of wearables, functional fabrics, mobile devices, wireless routers, and Internet of Things devices.
Dynamic Optical Grating Device for Modulating LightTBMG-3339912/01/2018
NASA Langley Research Center has developed a novel optical grating device that dynamically modulates light and is capable of controlling the spectral properties and propagation of light without any moving mechanical components.
Q&A: Dr. Sheng Xu, Department of NanoEngineering and the Center for Wearable Sensors, Jacobs School of Engineering, University of California San DiegoTBMG-3309210/01/2018
A team led by UCSD has built a stretchable electronic patch that can be worn on the skin like a bandage and used to wirelessly monitor a variety of physical and electrical signals, from respiration and body motion, to temperature and eye movement, to heart and brain activity. The device is as small and thick as a U.S. dollar coin.
Products of Tomorrow: August 2018TBMG-3248008/01/2018
This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that innovation.
Micro-Optomechanical Pressure Sensor Advances Pressure Monitoring in Biomedical ApplicationsTBMG-2797312/01/2017
A new type of pressure sensor is based on micro-optomechanical systems (MOMS) technology. Developed by imec, a research and innovation hub focusing on nanoelectronics and digital technologies, the sensor exhibits an excellent measurement precision in a large pressure range while being compact, resistant to electromagnetic interference (EMI), and having multiplexing capabilities. Leveraging imec's unique technical expertise in both MEMS and photonics, the sensor can be used in applications that require high-quality sensing, notably in the medical and life sciences domains.
Effect of Screens and Pinhole Size on Measured Fluctuating Surface Pressures Using a Micro-Electro-Mechanical Microphone Array2017-01-178306/05/2017
Surface pressure measurements using microphone arrays are still challenging, especially in an automotive context with cruising speeds around Mach 0.1. The separated turbulent boundary layer excitation and the side mirror wake flow generate both acoustic and aerodynamic components, which have wavenumbers that differ by a factor of approximately 10. This calls for high spatial resolution measurements to fully resolve the wavenumber-frequency spectrum. In a previous publication [1], the authors reported a micro-electro-mechanical (MEMS) surface microphone array that successfully used wavenumber analysis to quantify acoustic versus turbulence loading. It was shown that the measured surface pressure at each microphone could be strongly influenced by self-noise induced by the microphone “packaging”, which can be attenuated with a suitable windscreen. This paper reports the results of wind tunnel tests to more accurately define the sensitivity of the MEMS microphone array with and without
Todter, Chris, Robin, Olivier, Bremner, Paul, Marchetto, Christophe, Berry, Alain
Sonic Cyber Attack Shows Security Holes in Ubiquitous SensorsTBMG-2671004/01/2017
Sound waves could be used to hack into critical sensors in a broad array of technologies including medical devices, smart-phones, automobiles, and the Internet of Things, University of Michigan research shows.
Angular Random Walk Estimation of a Time-Domain Switching Micromachined GyroscopeTBMG-2668204/01/2017
The primary metrics that prohibit the use of microelectromechanical systems (MEMS) gyroscopes for navigation-grade inertial navigation units (IMUs) are angle random walk (ARW), bias instability, and scale factor instability. The need for MEMS gyroscopes is due to their decreased cost, size, weight, and power (CSWaP) constraints compared to current navigation-grade solutions. Note that to avoid confusion, while in a statistical context a random walk describes a particular type of random process, ARW is used herein to quantify the effects of white, or Gaussian, noise processes on the rate estimate of a gyroscope.
A Modular Apparatus and Method for Attaching Multiple DevicesTBMG-2664604/01/2017
Scientists at NASA's Glenn Research Center have received several patents for fabrication methods that speed the production of silicon carbide (SiC) sensors and electronics, reduce fabrication costs, and enable advanced semiconductor functionality at temperatures greater than 600 °C. Glenn has developed a method for fabricating ultra-thin SiC microstructures using a dopant selective reactive ion etching (DSRIE) technique that can create extremely thin diaphragms (approximately 2 microns), increasing sensor sensitivity and resolution. In addition, Glenn has developed a modular protective packaging that allows SiC-based electronic devices to survive and operate reliably at very high temperatures. These innovations improve the real-time monitoring of high-temperature harsh environments, such as jet and rocket engines, allowing faster response times and more accurate readings.
Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope17AERP04_1004/01/2017
Achieving near navigation-grade performance without the need to produce resonators with very high quality factors. Space and Naval Warfare Systems Center Pacific, San Diego, California The primary metrics that prohibit the use of microelectromechanical systems (MEMS) gyroscopes for navigation-grade inertial navigation units (IMUs) are angle random walk (ARW), bias instability, and scale factor instability. The need for MEMS gyroscopes is due to their decreased cost, size, weight, and power (CSWaP) constraints compared to current navigation-grade solutions. Note that to avoid confusion, while in a statistical context a random walk describes a particular type of random process, ARW is used herein to quantify the effects of white, or Gaussian, noise processes on the rate estimate of a gyroscope. The accepted theory about how to mitigate effects associated with thermomechanical noise, and thus lower ARW, quality factors on the order of a million are needed. While resonators with quality
Researchers Turn iPhone Camera into Optical SensorTBMG-2649103/01/2017
By integrating an optical Micro-Electro-Mechanical Systems, or MEMS, chip into an iPhone camera, researchers at the VTT Technical Research Centre of Finland have developed a new, cost-effective kind of hyperspectral technology. The spectral device will provide mobile device users and consumers with new ways to monitor their environments, including quick food analysis, health checks, and other Internet-connected sensing. Research team leader Anna Rissanen works actively with companies to enable commercialization and new business development based on the team's various sensors.
Gas Sensors with Contact PadsTBMG-2615601/01/2017
Innovators at NASA’s Glenn Research Center have developed advanced hydrogen and hydrocarbon gas sensors capable of detecting leaks, monitoring emissions, and providing in situ measurements of gas composition and pressure. These compact, rugged sensors can be used to optimize combustion and lower emissions, and they are designed to withstand harsh, high-temperature environments (e.g., silicon carbide (SiC) sensors can operate at 600 °C). NASA Glenn is actively seeking industrial partners to develop and apply these cutting-edge sensors cooperatively in new applications.
Piezoresistive SensorTBMG-2530109/01/2016
The present innovation, developed at NASA’s Goddard Space Flight Center, comprises several piezoresistor sensor configurations for sensing rotation or torque that are superior to those currently in use in microelectromechanical (MEMS) devices. These may be used for sensing rotation/torque or any other quantity that can be converted by the sensor to a rotation (as is frequently done in sensors), and are therefore of wide applicability in current and future MEMS sensors.
Aerospace & Defense Technology: June 201616AERP0606/01/2016
Digital Design Tools Simulating Thermal Expansion in Composites with Expanded Metal Foil for Lightning Protection Rugged Computing Designing VME Power Systems with Standard Modules Optical Sensors Optical Ice Sensors for UAVs Rotorcraft Technology Rotorcraft Icing Computational Tool Development RF & Microwave Technology Curled RF MEMS Switches for On-Chip Design: Design Software Supports BAE System's Mixed-Signal Chip Design
MEMS Oscillators with Improved Resilience for Harsh Automotive Environments2016-01-010104/05/2016
Oscillators are key components in automotive electronics systems. For example, a typical automotive camera module may have three or more oscillators, providing the clocks for microcontrollers, Ethernet controllers, and video chipsets. These oscillators have historically been built around a quartz crystal resonator connected to an analog sustaining circuit driving the crystal to vibrate at its resonant frequency. However, quartz-based devices suffer from poor performance and reliability in harsh automotive environments. SiTime has developed timing solutions based on silicon micro-electromechanical systems (MEMS) technology that exhibit better electromagnetic noise rejection and better performance under shock and vibration. In this paper, we first discuss the design and manufacturing of the MEMS-based device, with emphasis on the specific design aspects that improve reliability and resilience in harsh automotive environments. These aspects include the SOI-based MEMS fabrication process
Arft, Carl, Lu, Yin-Chen, Parvereshi, Jehangir
Fabrication of an Integrated Photonic Waveguide Joint in Micromachined SiliconTBMG-2425504/01/2016
High-aspect-ratio silicon structures are necessary components in many MEMS (microelectromechanical systems). Aspect ratio is defined as the ratio of the height of the structure to its lateral width. The structures are typically fabricated through bulk micromachining steps such as deep reactive ion etching. In some cases, multiple levels of high-aspect-ratio structures are required. For instance, one may want to etch completely through a silicon wafer to thermally isolate a bolometer or provide waveguide coupling to an antenna defined on an insulating membrane, and at the same time have integrated high-topology structures required for microwave coupling or filtering. Definition of the structures typically uses photolithographic technology. But for high-aspect-ratio structures, spin cast resist becomes difficult to incorporate due to the non-uniform thickness of the resist around tall structures. One can cast very thick layers of photoresist, but this limits the minimum feature size, and
MEMS Glow Discharge Plasma Electron and Ion SourceTBMG-2327611/01/2015
A microelectromechanical system (MEMS) glow discharge plasma electron and ion source (GDEIS) was designed for operation in high-pressure environments such as planetary atmospheres for mass spectroscopy. Glow discharge electron/ ion sources create electrons and ions from gas molecules in an excited plasma. A plasma is generated between two charged plates, and the polarity induced determines the electron or ion signal.
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