MIT News August 28, 2019 Piezoelectric materials produce a voltage in response to physical strain, and they respond to a voltage by physically deforming. Researchers at MIT developed an additive fabrication method to 3-D print ceramic transducers about 100 nanometers thin at room temperature. The films resonate at around 5 gigahertz, which is high enough for high-performance biosensors. The raw material used in 3-D printing — contains zinc oxide nanoparticles mixed with some inert solvents, which forms into a piezoelectric material when printed onto a substrate and dried. The researchers are currently working with colleagues to make piezoelectric biosensors to […]
Category Archives: Sensors
Portable radiation detectors make the invisible, visible
Physics World August 8, 2019 Traditionally, workers have used hand-held meters to survey small areas methodically, square centimetre by square centimetre. This process is cumbersome, and it can also mean that technicians spend unnecessarily long periods of time in dangerous environments. An international team of researchers (UK, Japan) developed Hot Spot Locator (HSL) that images gamma radiation similar to the way digital cameras image visible light. Signals from an array of high-energy radiation sensors are coupled with a coded aperture, a collection of around a dozen pinholes, which the HCL’s deconvolution algorithms can interpret to create a true image of […]
Emotion-detection applications built on outdated science, report warns
Science Daily July 18, 2019 The general public and some scientists believe that there are unique facial expressions that reliably indicate six emotion categories: anger, sadness, happiness, disgust, fear, and surprise. But in reviewing more than 1,000 published findings about facial movements and emotions, a team of researchers in the US (Northeastern University, Mass General Hospital, Caltech, the Ohio State University, University of Wisconsin) found that typical study designs don’t capture the real-life differences in the way people convey and interpret emotions on faces. They propose a new model for studying emotion-related responses in all their complexity and variations. This […]
Reversible electro-optical detector for environmental sensing of pollutants
Phys.org July 15, 2019 An international team of researchers (Spain, France, USA – Lawrence Berkeley National Laboratory) proposes the use of a simple non-porous coordination polymer that shows a magneto-structural transition under desorption/absorption of acetonitrile molecules in the structure. This reversible change produces a measurable response in the presence of acetonitrile. This response comes in the form of a change in the color of the polymer from orange to yellow and an abrupt increase in the electrical conductivity. Both responses are easily observed by the naked eye or easily measured, providing an obvious advantage over other costly analytical techniques. The […]
The Pentagon has a laser that can identify people from a distance—by their heartbeat
MIT Technology Review June 26. 2019 An individual’s cardiac signature is unique, it remains constant and cannot be altered or disguised. Researchers have developed a device called Jetson for the Pentagon which uses laser vibrometry to detect the surface movement caused by the heartbeat. It works at 200 meters (219 yards), longer distances could be possible with a better laser. A special gimbal was added so that an invisible, quarter-size laser spot could be kept on a target. It takes about 30 seconds to get a good return. They developed algorithms capable of extracting a cardiac signature from the laser […]
Sensors and metrology as the driving force for digitalization
Fraunhofer Research News June 19, 2019 Researchers in Germany will be presenting the results of their research into sensor technology and its applications in the field of testing and measurement at Sensor+Test 2019, a forum for sensor and measurement technology. They will demonstrate how the quality of workpieces and components can be assured using a non-contact, non-destructive test method based on audio sensing of product and process parameters combined with machine learning. The nanoSPECTRAL technology developed by Fraunhofer IIS is based on optical nanostructures and enables a very cost-effective monolithic production of the required optical filters directly in CMOS semiconductor […]
Hand-held scanner for detecting hazardous substances and explosives
Phys.org June 3, 2019 Researchers in Germany working under the EU project CHEQUERS www.chequers.eu combined very fast widely tunable quantum cascade lasers with adjusted transmission and receiver optics, fast IR detectors and a fitting control and detection software. The miniaturized quantum cascade laser with an external resonator can scan the whole spectral range of the QC laser chip within just a millisecond. The measuring principle is based on selective spectral lighting of the target in the wavelength range of 1000—1300 cm-1. The chemical substance is identified based on the intensity of the backscattered light and the illumination wavelength. The spectral […]
Hearing through your fingers: Device that converts speech
Medical Express June 3, 2019 An international team of researchers (Poland, Israel) hypothesized that they would be able to improve speech understanding under challenging conditions by exploiting the ability of the brain to integrate information coming simultaneously from different senses. They designed a minimalistic auditory-to-tactile sensory substitution device (SSD) that transforms low-frequency speech signals into tactile vibrations delivered on two fingertips. The reported improvement at the group level was 6 dB—a major difference considering that an increase of 10 dB represents a doubling of the perceived loudness. The device can provide immediate multisensory enhancement without any training. It has the […]
Household Radar Can See Through Walls and Knows How You’re Feeling
IEEE Spectrum May 30, 2019 Researchers at MIT have demonstrated a new technology that can infer a person’s emotions from RF signals reflected off a person’s body. EQ-Radio transmits an RF signal and analyzes its reflections off a person’s body to recognize his emotional state (happy, sad, etc.). The key enabler underlying EQ-Radio is a new algorithm for extracting the individual heartbeats from the wireless signal at an accuracy comparable to on-body ECG monitors. The resulting beats are then used to compute emotion-dependent features which feed a machine-learning emotion classifier. They describe the design and implementation of EQ-Radio, and demonstrate through […]
A new sensor for light, heat and touch
Phys.org May 14, 2019 Voltage arises in pyroelectric materials when they are heated or cooled. It is the change in temperature that gives a signal, which is rapid and strong, but it decays almost as rapidly. In thermoelectric materials, in contrast, a voltage arises when the material has one cold and one hot side. The signal here arises slowly, and some time must pass before it can be measured. Researchers in Sweden combined a pyroelectric polymer with a thermoelectric gel developed by them in a previous project. The combination gives a rapid and strong signal that lasts as long as […]