Phys.org June 2, 2021 An international team of researchers (USA – NIST, Jet Propulsion Laboratory, MIT, UK) has developed superconducting nanowire single-photon detectors based on tungsten silicide. To compensate for the lower energy carried by IR light they reduced the density of electrons in the wires that are available to absorb the photons. With fewer electrons available, the fraction of the total photon energy absorbed by any one electron is likely to be higher, increasing the likelihood that the electron would have enough energy to cross the superconducting gap and generate a signal when IR photons strike the detector. They […]
Category Archives: Sensors
Slender robotic finger senses buried items
MIT News May 26, 2021 Technologies that sense the subterranean from above provide only a hazy view of submerged objects. Researchers at MIT have designed Digger Finger to meet the challenge of identifying buried objects. The Digger Finger is a slender cylinder with a beveled tip and uses a combination of blue LEDs and colored fluorescent paint. Its tactile sensing membrane is about 2 square centimeters. They ran its vibrating motor at different operating voltages, which changes the amplitude and frequency of the vibrations. They found that rapid vibrations helped “fluidize” the media, clearing jams and allowing for deeper burrowing. […]
Ultrafast, on-chip PCR could speed diagnosis during pandemics
Phys.org May 26, 2021 Researchers in South Korea have developed a plasmofluidic PCR chip comprising glass nanopillar arrays with Au nanoislands and gas-permeable microfluidic channels, which contain reaction microchamber arrays, a precharged vacuum cell, and a vapor barrier. The on-chip configuration allows both spontaneous sample loading and microbubble-free PCR reaction during which the plasmonic nanopillar arrays result in ultrafast photothermal cycling. After rapid sample loading, two-step PCR results for 40 cycles show rapid amplification in 264 s for lambda-DNA, and 306 s for plasmids expressing SARS-CoV-2 envelope protein. In addition, the in situ cyclic real-time quantification of amplicons clearly demonstrates […]
Nuclear terrorism could be intercepted by neutron-gamma detector that pinpoints source
EurekAlert May 19, 2021 Researchers in Sweden have developed a Neutron-Gamma Emission Tomography (NGET) system that goes beyond the capabilities of existing radiation portal monitors, by measuring the time and energy correlations between particles emitted in nuclear fission and using machine learning algorithms to visualize where they are coming from. The system looks for coincidences of neutron and gamma ray emissions–which when mapped together in real-time allow pinpointing their origin. They demonstrated the method on a radiation portal monitor prototype system based on fast organic scintillators measuring the characteristic fast time and energy correlations between particles emitted in nuclear fission […]
Researcher uses bat-inspired design to develop new approach to sound location
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 […]
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. […]