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 […]
Category Archives: Sensors
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 […]
New tiny sensor makes the invisible visible
Phys.org January 12, 2022 Researchers in the Netherlands developed and demonstrated a different approach to spectral sensing which dramatically simplifies the requirements on the hardware and allows the monolithic integration of the sensors. They used an array of resonant-cavity-enhanced photodetectors, each featuring a distinct spectral response in the 850-1700 nm wavelength range. They showed that prediction models can be built directly using the responses of the photodetectors, despite the presence of multiple broad peaks, releasing the need for spectral reconstruction. They used the sensor to measure the nutritional properties of many materials including milk and to classify different types of plastic. […]
Novel biosensors set to revolutionize brain-controlled robotics
Science Daily December 22, 2021 Researchers in Australia have detected the EEG signals with high sensitivity using epitaxial graphene (EG) grown on silicon carbide on silicon. The dry and non-invasive approach exhibited a markedly improved skin contact impedance when benchmarked to commercial dry electrodes, as well as superior robustness, allowing prolonged and repeated use also in a highly saline environment. They observed a new phenomenon of surface conditioning of the EG electrodes. The prolonged contact of the EG with the skin electrolytes functionalize the grain boundaries of the graphene, leading to the formation of a thin surface film of water […]
Color-changing magnifying glass gives clear view of infrared light
Phys.org December 2, 2021 An international team of researchers (UK, Belgium, Spain) used a single layer of molecules to absorb the mid-infrared light inside their vibrating chemical bonds. These shaking molecules donate their energy to visible light that they encounter, ‘upconverting’ it to emissions closer to the blue end of the spectrum, which can then be detected by visible-light cameras. The challenge was to make sure the quaking molecules met the visible light quickly enough. They devised a way to sandwich single molecular layers between a mirror and tiny chunks of gold to twist and squeeze light. The researchers emphasize […]
Machine learning refines earthquake detection capabilities
Science Daily November 1, 2021 New satellites are opening a new window into tectonic processes by allowing researchers to observe length and time scales that were not possible in the past. However, existing algorithms are not suited for the vast amount of InSAR data flowing in from these new satellites. To process all this data an international team of researchers (USA – Los Alamos National Laboratory, France) developed the first tool based on machine learning algorithms to extract ground deformation from InSAR data, which enables the detection of ground deformation automatically — without human intervention — at a global scale, […]