Fibre optic technology is rapidly evolving, driven mainly by telecommunication and sensing applications. Excellent reliability of the manufacturing processes and low cost have drawn ever increasing attention to fibre-based sensors, e.g. for studying mechanical response/limitations of aerospace composite structures. Here, a vector bending and orientation distinguishing curvature sensor, based on asymmetric coupled multi-core fibre, is proposed and experimentally demonstrated. By optimising the mode coupling effect of a seven core multi-core fibre, we have achieved a sensitivity of - 1.4 nm/° as a vector bending sensor and - 17.5 nm/m as a curvature sensor. These are the highest sensitivities reported so far, to the best of our knowledge. In addition, our sensor offers several advantages such as repeatability of fabrication, wide operating range and small size and weight which benefit its sensing applications.
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http://dx.doi.org/10.1038/s41598-020-70999-8 | DOI Listing |
J Chem Phys
December 2024
Department of Physics, Kyungpook National University, Daegu, South Korea.
The freely jointed chain model with reversible hinges (rFJC) is the simplest theoretical model, which captures reversible transitions of the local bending stiffness along the polymer chain backbone (e.g., helix-coil-type of local conformational changes or changes due to the binding/unbinding of ligands).
View Article and Find Full Text PDFIn this Letter, we propose a new method utilizing femtosecond laser direct writing technology to rapidly inscribe high-quality tilted fiber Bragg gratings (TFBGs) in multicore fibers (MCFs). A series of TFBGs with varying tilt angles were directly inscribed in MCFs using the Plane-by-Plane (Pl-by-Pl) method, and the writing time for a 4 mm long TFBG was only 3.60 s.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), San Andrés Cholula 72840, Mexico.
A full characterization of multilayer ceramic capacitors including variations in capacitance, series resistance, and series inductance is accomplished by measuring their RF response while being submitted to mechanical stress. This allows for the first time quantifying the degradation of the device's RF performance when cracks form within its structure. In this regard, the main challenge is designing an interface for measuring the high-frequency response of a capacitor using a vector network analyzer as a bending test on a PCB in progress, which is achieved here by using a microstrip-based test fixture.
View Article and Find Full Text PDFWe introduced a two-dimensional vector-bending sensor using excessively tilted fiber grating (ExTFG) encapsulated in a non-neutral axis position within a flexible cylinder. The asymmetrical structure enabled both TM and TE modes of the ExTFG to achieve the competency of one-dimensional vector bending sensing by cleverly leveraging the orthogonal relationship between these modes to achieve the effect of orthogonal cascading of two one-dimensional sensors. The resonance wavelength changes of the TM and TE modes were monitored under equal excitation states to achieve two-dimensional vector bending sensing, which significantly simplified the manufacturing complexity of the sensor; the longer the off-axis distance, the higher the sensitivity, and the smaller the maximum measurable curvature.
View Article and Find Full Text PDFEMBO Mol Med
December 2024
Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK.
Bacterial cancer therapy (BCT) is a promising therapeutic for solid tumours. Salmonella enterica Typhimurium (STm) is well-studied amongst bacterial vectors due to advantages in genetic modification and metabolic adaptation. A longstanding paradox is the redundancy of T cells for treatment efficacy; instead, STm BCT depends on innate phagocytes for tumour control.
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