Phys.org March 24, 2022 Blow flies sample the environment as they search for water and food sources and can be trapped from kilometers away using baited traps. Researchers at Purdue University exposed three species of blow flies to the chemical warfare agent (CWA) simulants dimethyl methylphosphonate and diethyl phosphoramidate as well as the pesticide dichlorvos, followed by treatment-dependent temperature and humidity conditions. At intervals within a 14-day postexposure period the fly guts were extracted and analyzed. They found that the amount of CWA simulant in fly guts decreased with time following exposure but were detectable 14 days following exposure, giving […]
Category Archives: Sensors
Light derails electrons through graphene (w/video)
Nanowerk March 24, 2022 An international team of researchers (Spain, USA – Columbia University, Japan, Singapore) showed that by applying circular polarized infrared light onto the bilayer graphene device, they could selectively excite one specific valley population of electrons in the material, which generated a photovoltage perpendicular to the usual electron flow. By engineering the device and setup in such a way that current only flows with light illumination, they were able to avoid the background noise that hampers measurements and achieved a sensitivity in the detection several orders of magnitude better than any other 2D material. They could control […]
Novel quantum sensing possibilities with nonlinear optics of diamonds
Phys.org March 22, 2022 Taking advantage of the properties, especially the harmonic generation of nitrogen vacancy in diamond researchers Japan have presented an efficient and viable way for creating diamond-based nonlinear optical temperature sensing. Using infrared ultrashort pulse laser stimulation, the team found that the harmonic generation decreased with temperature over the range of 20–300°C. The temperature-dependent change was explained by mismatch due to the speed of different colors of light in the diamond. As the atomic lattice heats up, the difference in the index of refraction between the original light and the higher energy light created by harmonic generation […]
Physicists create compressible optical quantum gas
Phys.org March 24, 2022 The compressibility of a medium, quantifying its response to mechanical perturbations is a fundamental property determined by the equation of state. For gases of material particles studies of the mechanical response are well established in fields from classical thermodynamics to cold atomic quantum gases. Researchers in Germany demonstrated the measurement of the compressibility of a two-dimensional quantum gas of light in a box potential and obtained the equation of state for the optical medium. The experiment was carried out in a nanostructured dye-filled optical microcavity. They observed signatures of Bose-Einstein condensation at high phase-space densities in […]
Blowin’ in the wind – tiny battery-free sensor devices float like dandelion seeds (w/video)
Nanowerk March 16, 2022 Inspired by plants which disperse their seeds using the wind researchers at the University of Washington developed and demonstrated wind dispersal of battery-free wireless sensing devices. The millimetre-scale devices weigh 30 milligrams and were designed on a flexible substrate using programmable, off-the-shelf parts to enable scalability and flexibility for various sensing and computing applications. The system is powered using lightweight solar cells and an energy harvesting circuit that is robust to low and variable light conditions and has a backscatter communication link that enables data transmission. To achieve the wide-area dispersal and upright landing they developed thin-film […]
Hoverfly brains mapped to detect the sound of distant drones
Science Daily March 15, 2022 Insect vision systems have been mapped for some time now to improve camera-based detections. Researchers in Australia shown that it is possible pick up clear and crisp acoustic signatures of drones, including very small and quiet ones, using an algorithm based on the hoverfly’s visual system. They converted acoustic signals into spectrograms and used the neural pathway of the hoverfly brain to improve and suppress unrelated signals and noise, increasing the detection range for the sounds they wanted to detect. They looked for narrowband and/or broadband to pick up drone acoustics at short to medium […]
Arrays of metallic nanoparticles can form an optical cavity tunable by liquid crystals
Phys.org March 2, 2022 An international team of researcher (the Netherlands, Japan) designed, constructed, and analyzed a tunable device combining nano-particle arrays that support collective surface lattice resonances (SLRs) with liquid crystals. By leveraging the tunability of liquid crystals and the effect of the refractive index of the environment on SLRs, the optical response of the array can be controlled electrically by switching between states in the liquid crystal. The resulting rapid and reversible spectral tuning gives users a large degree of control over SLR wavelength. Because of narrow collective resonances the changes in refractive index that can be induced […]
Self-healing materials for robotics made from ‘jelly’ and salt
Science Daily February 18, 2022 There are numerous challenges in the deployment of wearable devices with soft sensing technologies due to their poor resilience, high energy consumption, and omnidirectional strain responsivity. Researchers in the UK have developed a versatile ionic gelatin-glycerol hydrogel for soft sensing applications. The device is inexpensive and easy to manufacture, self-healable at room temperature, can undergo strains of up to 454%, presents stability over long periods of time, and is biocompatible and biodegradable. The material is ideal for strain sensing applications, with a linear correlation coefficient R2 = 0.9971 and a pressure-insensitive conduction mechanism. The experimental results show […]
Towards self-sensing soft robots with electrochemically driven pumps
Science Daily February 8, 2022 Researchers in Japan based the electrochemical dual transducer (ECDT) design on the electrohydrodynamic (EHD) pump they had previously designed. The pump consisted of a symmetrical arrangement of planar electrodes, which allowed easy control of the flow direction by simply changing the voltage. The arrangement enabled an obstruction-free even flow in each direction due to the same strength of the electric field on either side. They evaluated sensing performance in terms of range of detectable flow, rate, sensitivity, response, and relaxation times, and used mathematical modeling to understand the sensing mechanism. The ECDT does not require […]
Just listen to the chaos: A new approach to extracting information from large ensembles of sensors
Nanowerk January 24, 2022 In distributed sensing approaches where readouts are obtained directly at the ensemble level, generally requires sensor nodes capable of interacting with each other to implement the required readout statistic. An international team of researchers (Japan, Italy) developed an experimental set up based on chaotic synchronization. They found single-transistor oscillators, representing remarkably low-complexity yet highly flexible entities to be suitable for wireless coupling via mutual induction, realizing a simple form of telemetry for luminous flux. Using numerical simulations and numerous laboratory experiments they demonstrated a rich repertoire of possible interactions among multiple sensor nodes and between the same […]