EurekAlert September 14, 2020 Researchers in Sweden prepared one atom thin, electrically continuous platinum layers by physical vapor deposition on the carbon zero layer (buffer layer) grown epitaxially on silicon carbide. With a thin Pt layer, the electrical conductivity of the metal is strongly modulated when interacting with chemical analytes, due to charges being transferred to/from Pt. The strong interaction with chemical species, together with the scalability of the material, enables the fabrication of chemiresistor devices for electrical read‐out of chemical species with sub part‐per‐billion detection limits. This opens a route for resilient and high sensitivity chemical detection and can […]
Category Archives: Sensors
Researchers make tiny, yet complex fiber optic force sensor
Phys.org September 8, 2020 Researchers in Slovenia designed sensor consisting of a thin silica diaphragm created at the tip of the fiber. The central part of the diaphragm is extended into a silica pole, which ends with a round-shaped probe or a sensing cylinder. The entire sensor is made of silica glass and has a cylindrical shape with a length of about 800 µm and a diameter of about 105 µm. Force sensing resolution of about 0.6 µN was demonstrated experimentally while providing an unambiguous sensor measurement range of about 0.6 mN. It overcomes the limitations of force sensors and […]
A colorful detector: Crystalline material reversibly changes color when absorbing water
Science Daily August 25, 2020 To ensure safety and efficiency factories often need to be monitored for potentially toxic gasses or even excess humidity. Sensors for water vapor are particularly important for monitoring toxic gasses or even excess humidity. But they may have limited lifetimes or require external power. An international team of researchers (Japan, Spain) formed van der Waals porous crystal (VPC-1) from an aromatic dendrimer containing carbon rings anchored to a dibenzophenazine core. Even though van der Waals forces are usually considered to be relatively weak, the crystal stays together during operation. Upon exposure to water vapor, the […]
New LiDAR Sensor Uses Mirrors to Achieve High Efficiency
IEEE Spectrum August 21, 2020 An international team of researchers (USA – University of Florida, China) designed and fabricated a MEMS mirror specifically designed with direct actuation from the microcontroller. It is powered by a 9-V commercial battery. Instead of a motorized optomechanical scanner, the system relies on MEMS mirrors to control the LiDAR signals. The mirrors require significantly less power to manipulate than the bulkier motorized scanner that have typically been used. A passive infrared sensor ensures that the whole system is only activated when people are present. It may have applications ranging from robotics to small unmanned air […]
Trace vapor generator for detecting explosives, narcotics
Science Daily August 18, 2020 The Trace Vapor Generator for Explosives and Narcotics (TV-Gen) sampling device designed by a team of researchers in the US (Naval Research Laboratory, research institution, National Research Council) can be used with a broad range of analytes, detection systems, materials, and sensors. It can switch easily between the clean and analyte vapor streams. The TV-Gen system utilizes nebulization of aqueous analyte solutions and a control box that provides dedicated computer control with logging capabilities. Resultant vapor streams are stable over several hours, with the vapor concentration controlled by a combination of aqueous analyte solution concentration, […]
Novel magnetic stirrer speaks to lab equipment
Science Daily August 3, 2020 Researchers in the UK have developed a device, called “Smart Stirrer”. When immersed in a solution, it can in situ monitor physical properties of the chemical reaction such as the temperature, conductivity, visible spectrum, opaqueness, stirring rate, and viscosity. This data is transmitted real-time over a wireless connection to an external system, such as a PC or smartphone. The flexible open-source software architecture allows effortless programming of the operation parameters of the Smart Stirrer in accordance with the end-user needs. In a series of experiments its capability for many hours of continuous telemetry with fine […]
Metal-breathing bacteria could transform electronics, biosensors, and more
Science Daily July 28, 2020 Some bacteria that are adapted to specific geochemical or biochemical environments can create interesting and novel materials. Researchers at the Rensselaer Polytechnic Institute synthesised molybdenum disulfide nanomaterials at the site of S. oneidensis biofilms grown in the presence of molybdenum trioxide and sodium thiosulfate. Analysis revealed the presence of molybdenum disulfide nanoparticle aggregates 50–300 nm in diameter with both hexagonal and rhombohedral polytypes. The use of S. oneidensis offers the advantage of significantly reduced heat and chemical solvent input compared to conventional methods of synthesizing molybdenum disulfide nanoparticles. The process can be used for the generation […]
Liquid crystals create easy-to-read, color-changing sensors
Nanowerk July 11, 2020 Inspired by the ability of chameleons to change color by using temperature to direct the skin tissue that contains nanocrystals reflecting light, to expand or contract, an international team of researchers (USA – University of Chicago, University of South Carolina, University of North Texas, Cornell University, Argonne National Laboratory, Mexico, Turkey, Colombia) has developed a way to stretch and strain liquid crystals to generate different colors. They dispersed chiral droplets in polymer films and deformed it by inducing uniaxial or biaxial stretching. Their measurements are interpreted by resorting to simulations of the corresponding systems, thereby providing […]
‘Nanometrology lab on a chip’ within reach thanks to new compact, optical sensor
Nanowerk May 20, 2020 On-chip compact and integrated optical motion sensing micro- and nano-optomechanical platforms that typically exploit narrow spectral resonances require tunable lasers with narrow linewidth and low spectral noise, which makes the integration of the read-out extremely challenging. Researchers in the Netherlands report a step towards the practical application of nanomechanical sensors, by presenting a sensor with ultrawide (∼80 nm) optical bandwidth. It is based on a nanomechanical, three-dimensional directional coupler with integrated dual-channel waveguide photodiodes and displays small displacement imprecision as well as large dynamic range (>30 nm). The broad optical bandwidth releases the need for a tunable laser […]
Catching nuclear smugglers: Fast algorithm could enable cost-effective detectors at borders
EurekAlert April 30, 2020 An international team of researchers (USA – University of Michigan, University of Illinois, Los Alamos National Laboratory, UK) developed an algorithm capable of identifying weak radiation signals, such as might be seen from plutonium encased materials that absorb radiation. It works even in the presence of a high radiation background, including everyday sources such as cosmic rays from space and radon from the rock underfoot. Based on their results, they believe the use of their algorithm could improve the ability of radiation portal monitors at national borders to tell the difference between potential smuggling activity and […]