Phys.org April 8, 2024 An international team of researchers (Japan, Taiwan, Mexico, Australia) demonstrated the passive, diamagnetic levitation of a centimeter-sized massive oscillator, which was fabricated ensuring that the material, though highly diamagnetic, was an electrical insulator. By chemically coating a powder of microscopic graphite beads with silica and embedding the coated powder in high-vacuum compatible wax, they formed a centimeter-sized thin square plate which magnetically levitated over a checkerboard magnet array. The insulating coating reduced eddy damping by almost an order of magnitude compared to uncoated graphite with the same particle size. The plates exhibited a different equilibrium orientation […]
Tag Archives: Sensors
Research team realizes magnonic frequency comb
Phys.org April 1, 2024 A direct analog of frequency combs in the magnonic systems has not been demonstrated to date. Researchers in China generated a new magnonic frequency comb in the resonator with giant mechanical oscillations through the magnomechanical interaction. It contained up to 20 comb lines, which were separated by the mechanical frequency of 10.08 MHz. The thermal effect based on the strong pump power induced the cyclic oscillation of the magnon frequency shift, which led to a periodic oscillation of the magnonic frequency comb. They demonstrated the stabilization and control of the frequency spacing of the magnonic frequency […]
Researchers discover new ultra strong material for microchip sensors
Phys.org November 2, 2023 Although there have been remarkable strides in achieving low-dissipation mechanical sensors by utilizing high tensile stress, the performance of even the best strategy is limited by the tensile fracture strength of the resonator materials. An international team of researchers (the Netherlands, USA – Brown University) found that a wafer-scale amorphous thin film of silicon carbide (SiC) material exhibited an ultimate tensile strength of over 10 GPa, reaching the regime reserved for strong crystalline materials and approaching levels experimentally shown in graphene nanoribbons. They fabricated amorphous SiC strings with high aspect ratios with mechanical modes exceeding quality […]
Physicists create new form of antenna for radio waves
Phys.org October 18, 2023 Researchers in New Zealand used a small glass bulb containing an atomic vapor to demonstrate a new form of antenna for radio waves. The bulb was “wired up” with laser beams and could therefore be placed far from any receiver electronics. They combined a rubidium vapor cell with a corner-cube prism reflector to form a passive RF transducer, allowing the detection of microwave signals at a location distant from the active components required for atomic sensing. The transducer had no electrical components and was optically linked to an active base station by a pair of free-space […]
Tiny magnetic beads produce an optical signal that could be used to quickly detect pathogens
MIT News August 25, 2023 Researchers at MIT have identified a new optical signature in a widely used class of magnetic beads, which could be used to quickly detect contaminants in a variety of diagnostic tests. They used Dynabeads coated with anti-Salmonella to bind and identify Salmonella enterica. Dynabeads presented signature peaks at 1000 and 1600 1/cm from aliphatic and aromatic C-C stretching of polystyrene, and 1350 1/cm and 1600 1/cm from amide, alpha-helix, and beta-sheet of antibody coatings of the Fe2O3 core, confirming with electron dispersive X-ray imaging. The Raman signature could be measured in dry and liquid samples. […]
Innovative paper-like, battery-free, AI-enabled sensor for holistic wound monitoring
Nanowerk June 26, 2023 Researchers in Singapore developed a paper-like battery-free in situ AI-enabled multiplexed (PETAL) sensor for holistic wound assessment by leveraging deep learning algorithms. This sensor consisted of a wax-printed paper panel with five colorimetric sensors for temperature, pH, trimethylamine, uric acid, and moisture. Sensor images captured by a mobile phone were analyzed by neural network–based machine learning algorithms to determine healing status. For ex situ detection via exudates collected from rat perturbed wounds and burn wounds, the PETAL sensor could classify healing versus nonhealing status with an accuracy as high as 97%. With the sensor patches attached […]
New sensors with the HOTS for extreme missions
DARPA News May 12, 2023 The performance of many of the defense and industrial systems that rely on sensors experience harsh environments beyond the capability of today’s high-performance physical sensors, they are limited by the uncertainty of their thermal environments. Today, sensors that can withstand thermally harsh conditions are limited to low-sensitivity transducers located in hot zones coupled via noisy electrical connections to remote, temperature-constrained, silicon signal-conditioning microelectronics in cold zones. The resulting integrated sensors lack the combination of frequency bandwidth and dynamic range essential for high-temperature missions. If we can design, integrate, and demonstrate high-performance physical sensors that can […]
Developing Agile, Reliable Sensing Systems with Microbes
DARPA April 21, 2023 DARPA’s new Tellus program will explore the development of an interactive, platform methodology for the rapid design of microbe-based sense-and-respond devices for monitoring DOD-relevant environments. Specifically, DARPA seeks to establish the range of chemical and physical signals that microbial devices can detect, environmental conditions they can tolerate, and types of output signals that can be generated. They envision a dashboard or interface where a user would dial in features of their environment, the inputs they want to detect, and the output signals that are useful to them, and the system would design a safe, effective microbial […]
Imaging technique reveals electronic charges with single-atom resolution
Phys.org March 31, 2023 A Kondo lattice is often electrically insulating at low temperatures. However, several recent experiments have detected signatures of bulk metallicity within this Kondo insulating phase. An international team of researchers (USA – Harvard University, University of Illinois, University of Maryland, Stanford University, UK) visualized the real-space charge landscape within a Kondo lattice with atomic resolution using a scanning tunneling microscope. They discovered nanometer-scale puddles of metallic conduction electrons centered around uranium-site substitutions in the heavy-fermion compound uranium ruthenium silicide (URu2Si2) and around samarium-site defects in the topological Kondo insulator samarium hexaboride (SmB6). These defects disturbed the […]
New microchip links two Nobel Prize-winning techniques
Science Daily March 22, 2023 Mechanical frequency combs are poised to bring the applications and utility of optical frequency combs into the mechanical domain. So far, their main challenge has been strict requirements on drive frequencies and power, which complicate operation. An international team of researchers (the Netherlands, USA – NIST) has demonstrated a straightforward mechanism to create a frequency comb consisting of mechanical overtones (integer multiples) of a single eigenfrequency, by monolithically integrating a suspended dielectric membrane with a counter-propagating optical trap. The periodic optical field modulated the dielectrophoretic force on the membrane at the overtones of a membrane’s […]