Phys.org August 26, 2024 Spin squeezing is a form of entanglement that reshapes the quantum projection noise to improve measurement precision. An international team of researchers (USA – Harvard University, UC Berkeley, Germany) provided numerical and analytic evidence for the following conjecture: any Hamiltonian exhibiting finite-temperature easy-plane ferromagnetism could be used to generate scalable spin squeezing, thereby enabling quantum-enhanced sensing. It is based on a connection between the quantum Fisher information of pure states and the spontaneous breaking of a continuous symmetry. They demonstrated that spin squeezing exhibits a phase diagram with a sharp transition between scalable squeezing and non-squeezing […]
Category Archives: Sensors
‘Amphibious’ sensors make new, waterproof technologies possible
EurekAlert August 7, 2024 Researchers at North Carolina State University have developed an encapsulated stretchable amphibious strain sensor. They sandwiched conductive layer made of silver nanowires embedded below the surface of polydimethylsiloxane by two layers of thermoplastic polyurethane. They introduced periodic sharp cuts to change the direction of flow from across the sensor to along the conductive path defined by the opening cracks. The crack advancing and opening was controlled by a unique combination of weak/strong interfaces within the sandwich structure. The strain sensor exhibited a high gauge factor, excellent robustness against over-strain, and stability after 16 000 loading cycles and […]
Self-assembling, highly conductive sensors could improve wearable devices
Science Daily July 1, 2024 Soft and stretchable conductors with high electrical conductivity and tissue-like mechanical properties are crucial for both on-skin and implantable electronic devices. Liquid metal-based conductors hold great promise due to their metallic conductivity and minimal stiffness. However, the surface oxidation of liquid metal particles in polymeric matrices poses a challenge in forming a continuous pathway for highly conductive elastic composites. Researchers at the Pennsylvania State University reported a printable composite material based on liquid metal and conducting polymer that undergoes a self-assembly process, achieving high conductivity in the bottom surface while maintaining an insulated top surface, […]
An optical lens that senses gas
Nanowerk June 26, 2024 Hybrid glasses derived from meltable metal-organic frameworks (MOFs) promise to combine the intriguing properties of MOFs with the universal processing ability of glasses. Researchers in Germany developed optical-quality glasses derived from the zeolitic imidazole framework which allowed them to perform in-depth studies of optical transparency and refraction across the ultraviolet to near-infrared spectral range. Using this fundamental data, they demonstrated the fabrication of micro-optical devices by thermal imprinting. They showed that concave as well as convex lens structures could be obtained at high precision by remelting the glass without trading-off on material quality. This enabled multifunctional […]
Optical barcodes expand range of high-resolution sensor
Phys.org April 26, 2024 In the field of optical sensing, Whispering-Gallery-Mode (WGM) microresonators have emerged as promising candidates, offering the advantages of high sensitivity, high resolution, and small footprint. However, conventional sensing methods, which rely on tracking changes in a single mode, have a limited dynamic range of measurement. Researchers at Washington University developed a theoretical framework that offers comprehensive analytical insights for multimode-sensing techniques and demonstrated an optical WGM barcode technique that enabled simultaneous monitoring of the patterns of multiple modes that could provide over-FSR (Free spectral range) tracking with high resolution. They assessed the theoretical limits of measurement […]
Waterproof ‘e-glove’ could help scuba divers communicate
Nanowerk April 10, 2024 Existing tactile sensing gloves fall short in terms of user comfort and are ill-suited for underwater applications. Researchers in China proposed and constructed a flexible hand gesture recognition glove (GRG) that contained high-performance micropillar tactile sensors (MPTSs) inspired by the flexible tube foot of a starfish. The sensor has a wide working range, superfast response time, reliable repeatability, and a low limit of detection and they were waterproof. When integrated with machine learning algorithm, the GRG system achieved intelligent recognition of 16 hand gestures under water, extending real-time and effective communication capabilities for divers. According to […]
Research team creates global roadmap to advance printable sensors for sustainability and quality of life
Phys.org March 25, 2024 The dissemination of sensors could advance the sustainability and quality of our lives. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing; printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates. Device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes are necessary. An international team of researchers (Canada, Italy, USA – University of Wisconsin, Northwestern University, the Netherlands, […]
Novel method improves Fourier transform infrared spectroscopy detection of ultra-low concentration trace substances
Phys.org March 7, 2024 High-resolution solar spectra play a crucial role in research pertaining to atmospheric vertical profiles and analysis of atmospheric composition. However, the improvement of spectral resolution is subject to certain limitations due to hardware constraints. Researchers in China proposed multi-step linear prediction (MSLP) method based on sliding windows to enhance the spectral resolution of passive remote sensing FTIR spectra, thereby improving the accuracy and reliability of atmospheric composition analysis. Their method improved the spectral resolution of passive remote sensing FTIR spectra. In simulations, the MSLP method significantly enhanced the spectral resolution of passive remote sensing FTIR spectra. […]
Paper AI sensor mimics brain for health monitoring
Nanowerk March 11, 2024 Physical reservoir computing (PRC), which mimics the human brain using physical phenomena, offers a low-power consumption architecture. However, creating a flexible and easily disposable sensors using PRC capable of processing optical signals with sub-second response times suitable for biological signals presents a challenge. Researchers in Japan designed disposable and flexible paper-based optoelectronic synaptic devices which are composed of nanocellulose and ZnO nanoparticles, for PRC. The device exhibited synaptic photocurrent in response to optical input. The memory capacity of short-term memory task, indicating the device’s ability to store past information was 1.8. It could recognize handwritten digits […]
Correlation spectroscopy research shows network of quantum sensors boosts precision
Phys.org March 4, 2024 The coherence time of the quantum system surpasses that of the oscillator probing the system. Correlation spectroscopy overcomes this limitation by probing two quantum systems with the same noisy oscillator for a measurement of their transition frequency difference enabling very precise comparisons of atomic clocks. An international team of researchers (Austria, Israel, USA – Caltech) extended correlation spectroscopy to the case of multiple quantum systems undergoing strong correlated dephasing. They modelled Ramsey correlation spectroscopy with N particles as a multiparameter phase estimation problem and demonstrated that multiparticle correlations could assist in reducing the measurement uncertainties even […]