Science Daily April 15, 2021 Inspired by the bat ears, researchers at Virginia Tech designed a soft-robotic sensor that mimics fast non-rigid deformation of the ears in bats. They placed the ear above a microphone, creating a mechanism similar to that of a bat. The fast motions of the fluttering outer ear of the bat created Doppler shift signatures. To interpret this complex pattern, they trained a computer to provide the source direction associated with each received echo using deep neural network. Once the direction of the sound was determined, the control computer would rotate the rig so that the […]
Category Archives: Sensors
With impressive accuracy, dogs can sniff out coronavirus
Phys.org April 15, 2021 In a proof-of-concept study a team of researchers in the US (U Penn, industry) utilized detection dogs to investigate whether SARS-CoV-2 positive urine and saliva patient samples had a unique odor signature. Using detergent-inactivated urine samples, dogs were initially trained to find samples collected from hospitalized patients confirmed with SARS-CoV-2 infection, while ignoring samples collected from controls. Dogs were then tested on their ability to spontaneously recognize heat-treated urine samples as well as heat-treated saliva from hospitalized SARS-CoV-2 positive patients. Dogs successfully discriminated between infected and uninfected urine samples, regardless of the inactivation protocol, as well […]
Detecting hidden signals
EurekAlert March 25, 2021 The field of quantum sensing has shown a lot of potential for detecting very small signals. However, the ability to truly optimize these sensors has been thwarted by the complexity of control schemes. A team of researchers in the US (Johns Hopkins University, University of Maryland) applied filter functions and optimal quantum control theories to a use case of qubit sensors that mirror a classic problem in signal detection theory: optimal detection of a known signal from background noise with a controllable quantum sensor. They obtained analytical insight into the optimal control protocol when the background […]
Fast-acting, color-changing molecular probe senses when a material is about to fail
Science Daily March 25, 2021 A team of researchers at the University of Illinois have improved their previously developed mechanophores (force-sensitive molecules) where the molecules were slow to react and return to their original state. The new mechanophores, they developed produced reversible, rapid, and vibrant color change when a force was applied. The color change is the result of stress applied to the bonds that connect the mechanophores to a polymer chain. In the current work they are bonding the mechanophores to polymer chains using a different arrangement scheme, called an oxazine structure. The new structure allows for an instantaneous […]
Object classification through a single-pixel detector
Phys.org March 29, 2021 To mitigate the shortcomings and inefficiencies of traditional machine vision systems researchers at UCLA leveraged deep learning to design optical networks created by successive diffractive surfaces to perform computation and statistical inference as the input light passes through specially designed and 3D-fabricated layers. The diffractive optical networks are designed to process the incoming light at selected wavelengths with the goal of extracting and encoding the spatial features of an input object onto the spectrum of the diffracted light, which is collected by a single-pixel detector. Different object types or classes of data are assigned to different […]
Researchers virtually open and read sealed historic letters
MIT News March 2, 2021 Computational flattening algorithms have been successfully applied to X-ray microtomography scans of damaged historical documents, but have so far been limited to scrolls, books, and documents with one or two folds. An international team of researchers (US -MIT, industry, UK, the Netherlands) used automated computational flattening algorithm to read an unopened letter from early modern Europe without breaking its seal or damaging it in any way. They reconstructed the intricate folds, tucks, and slits of unopened letters secured shut with “letterlocking,” a practice—systematized in this paper—which underpinned global communications security for centuries before modern envelopes. […]
Adapting solar energy technology to detect chemical warfare agents and pesticides
Nanowerk March 4, 2021 The wrong amounts or incorrect use of these fumigants like methyl iodide can be harmful to people and degrade the ozone layer. Researchers in Australia borrowed a new technology that is being used to improve solar power – synthetic nanocrystals based on a perovskite structure – and turned it into a detection method. The presence of methyl iodide causes the nanocrystal emission to shift from green to yellow, and then on to orange, red, and finally deep red, depending on the amount of fumigant present. They demonstrated that the change in colour is dependent on the […]
Researchers explore using light to levitate discs in the mesosphere
Phys.org February 15, 2021 To improve weather prediction sensors need to be sent to mesosphere. The satellites and rockets currently used have problems as the air is too thick and friction and heat would make long-duration flights impractical. Researchers at the University of Pennsylvania constructed and demonstrated light-driven levitation of macroscopic polymer films with nanostructured surface as candidates for long-duration near-space flight. The disks were made of 0.5-micron-thick mylar film coated with carbon nanotubes on one side. When illuminated with light intensity comparable to natural sunlight, the polymer disk heats up and interacts with incident gas molecules differently on the […]
Rapid Identification of Ricin in Serum Samples Using LC–MS/MS
Global Biodefense January 23, 2021 Researchers in Israel have developed a sensitive, rapid, antibody-independent assay for the identification of ricin in body fluids using mass spectrometry. The assay involves lectin affinity capturing of ricin by easy-to-use commercial lactose–agarose beads, followed by tryptic digestion and selected marker identification using targeted Multiple Reaction Monitoring analysis. This enables ricin identification down to 5 ng/mL in serum samples in 2.5 hours. They demonstrated the technology in a clinical scenario where the toxin was identified in an abdominal fluid sample taken 72 h post self-injection of castor beans extraction. This method has the potential application […]
Researchers report quantum-limit-approaching chemical sensing chip
Phys.org January 11, 2021 To fabricate high‐density random metallic nanopatterns with accurately controlled nanogaps an international team of researchers (USA – SUNY Buffalo, China, Saudi Arabia) used four molecules (BZT, 4-MBA, BPT, and TPT), each with different lengths. They used atomic layer deposition and self-assembled monolayers instead of electron-beam lithography. The resulting SERS (surface-enhanced Raman spectroscopy) chip with unprecedented uniformity is relatively inexpensive to produce and has gap size approaching the quantum regime of ≈0.78 nm. They demonstrated its potential for quantitative sensing with the relative standard deviation of 4.3% over large area. All chemicals have unique light-scattering signatures; therefore, […]