Principles and Applications of Nanoplasmonics in Biological and Chemical Sensing: A Review

Biosensing requires a highly sensitive real-time detection of the biomolecules. These properties are granted by nanoplasmonic sensing techniques. SPR-based optical sensors have evolved as a sensitive and versatile biosensing tool. A growing number of SPR-based sensing applications in the solution of clinical problems are reported in the recent years. This refers to the point that these sensors provide label-free detection of the living cells and non-destructive analysis techniques. In this study, we will review the mechanism of the detection in SPR biosensing, followed by the methods used to develop sensors to detect gases and the chemical, biological, and molecular interaction. The device sensitivity improvement based on plasmonic effects is also addressed in this study, and accordingly, the size and material dependence of the resonance frequency are discussed. The reviewed articles are categorized into three groups, depending on the SPR excitation configuration. In the first group of the sensors, the sensitivity of LSPR-based sensors in prism coupler configurations is reviewed. The second group, SPR excitation by optical fiber, slightly improved the sensitivity of the detections. The unique capability of the third group, photonic crystal fiber SPR sensors, in providing greatly improved sensitivity, generated a vast field of researches and applications in biosensing devices.

ИССЛЕДОВАНИЕ ТРЕХОСЕВОГО МИКРОМЕХАНИЧЕСКОГО АКСЕЛЕРОМЕТРА

Исследована конструкция сенсора линейного ускорения с тремя осями чувствительности. На основании результатов исследования определены чувствительность трехосного сенсора, перекрестная чувствительность, длительность переходных процессов. В рамках работы изготовлены опытные образцы сенсоров. The paper highlights the linear acceleration sensor design with three axis of sensitivity the basis of the research results Three-axis device sensitivity, cross-sensitivity, and duration transients have been specified on. As part of the work the experimental sensor prototypes have been fabricated.

Sensitivity investigation of the microfiber-toslab evanescent wave sensors

Microfiber-to-slab sensor is comprised of a tapered fiber in evanescent contact with a multimode slab waveguide. The effects of the sensor configuration parameters on its evanescent wave sensitivity were investigated through theoretical analysis. On the basis of that, the rules for fabricating a microfiber-to-slab sensor with high device sensitivity were presented. By optimizing geometry parameters, it was shown that the resonant wavelength sensitivity can be as high as nearly 20000 nm/RIU. The conclusions derived from our work may be used for design and optimization of microfiber-to-slab devices for practical applications.

Design and Optimization of a MEMS-Based Piezoresistive Accelerometer for Head Injuries Monitoring: A Computational Analysis

This work focuses on the design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common, for example in sports such as racing cars or American Football. The device requires the highest sensitivity achievable with a single proof mass approach, and a very low error (<1%) as the accuracy for these types of applications is paramount. The optimization method differs from previous work as it is based on the progressive increment of the sensor mass moment of inertia (MMI) in all three axes. The work numerically demonstrates that an increment of MMI determines an increment of device sensitivity with a simultaneous reduction of cross-talk in the particular axis under study. The final device shows a sensitivity increase of about 80% in the Z-axis and a reduction of cross-talk of 18% respect to state-of-art sensors available in the literature. Sensor design, modelling and optimization are presented, concluding the work with results, discussion and conclusion.