scholarly journals An Ultra-Sensitive Multi-Functional Optical Micro/Nanofiber Based on Stretchable Encapsulation

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7437
Author(s):  
Siheng Xiang ◽  
Hui You ◽  
Xinxiang Miao ◽  
Longfei Niu ◽  
Caizhen Yao ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Optical Sensors ◽  
High Sensitivity ◽  
Gauge Factor ◽  
Practical Application ◽  
Fiber Sensors ◽  
Highly Sensitive ◽  
Wide Range ◽  
Peak Sensitivity ◽  
Robust Sensing

Stretchable optical fiber sensors (SOFSs), which are promising and ultra-sensitive next-generation sensors, have achieved prominent success in applications including health monitoring, robotics, and biological–electronic interfaces. Here, we report an ultra-sensitive multi-functional optical micro/nanofiber embedded with a flexible polydimethylsiloxane (PDMS) membrane, which is compatible with wearable optical sensors. Based on the effect of a strong evanescent field, the as-fabricated SOFS is highly sensitive to strain, achieving high sensitivity with a peak gauge factor of 450. In addition, considering the large negative thermo-optic coefficient of PDMS, temperature measurements in the range of 30 to 60 °C were realized, resulting in a 0.02 dBm/°C response. In addition, wide-range detection of humidity was demonstrated by a peak sensitivity of 0.5 dB/% RH, with less than 10% variation at each humidity stage. The robust sensing performance, together with the flexibility, enables the real-time monitoring of pulse, body temperature, and respiration. This as-fabricated SOFS provides significant potential for the practical application of wearable healthcare sensors.

scholarly journals Carbon Allotrope-Based Optical Fibers for Environmental and Biological Sensing: A Review

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2046 ◽  
Author(s):  
Stephanie Hui Kit Yap ◽  
Kok Ken Chan ◽  
Swee Chuan Tjin ◽  
Ken-Tye Yong
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
High Sensitivity ◽  
Optical Fiber Sensors ◽  
Functional Coating ◽  
Fiber Sensors ◽  
Carbon Allotrope ◽  
Carbon Allotropes ◽  
Sensing Technology ◽  
Wide Range

Recently, carbon allotropes have received tremendous research interest and paved a new avenue for optical fiber sensing technology. Carbon allotropes exhibit unique sensing properties such as large surface to volume ratios, biocompatibility, and they can serve as molecule enrichers. Meanwhile, optical fibers possess a high degree of surface modification versatility that enables the incorporation of carbon allotropes as the functional coating for a wide range of detection tasks. Moreover, the combination of carbon allotropes and optical fibers also yields high sensitivity and specificity to monitor target molecules in the vicinity of the nanocoating surface. In this review, the development of carbon allotropes-based optical fiber sensors is studied. The first section provides an overview of four different types of carbon allotropes, including carbon nanotubes, carbon dots, graphene, and nanodiamonds. The second section discusses the synthesis approaches used to prepare these carbon allotropes, followed by some deposition techniques to functionalize the surface of the optical fiber, and the associated sensing mechanisms. Numerous applications that have benefitted from carbon allotrope-based optical fiber sensors such as temperature, strain, volatile organic compounds and biosensing applications are reviewed and summarized. Finally, a concluding section highlighting the technological deficiencies, challenges, and suggestions to overcome them is presented.

scholarly journals Flexible and Highly Sensitive Strain Sensor Based on Laser-Induced Graphene Pattern Fabricated by 355 nm Pulsed Laser

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4867 ◽  
Author(s):  
Sung-Yeob Jeong ◽  
Yong-Won MA ◽  
Jun-Uk Lee ◽  
Gyeong-Ju Je ◽  
Bo-sung Shin
Keyword(s):  
Focal Length ◽  
Pulsed Laser ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Gauge Factor ◽  
Functional Evaluation ◽  
Mechanical Fracture ◽  
Highly Sensitive ◽  
Human Finger ◽  
Small Deformations

A laser-induced-graphene (LIG) pattern fabricated using a 355 nm pulsed laser was applied to a strain sensor. Structural analysis and functional evaluation of the LIG strain sensor were performed by Raman spectroscopy, scanning electron microscopy (SEM) imaging, and electrical–mechanical coupled testing. The electrical characteristics of the sensor with respect to laser fluence and focal length were evaluated. The sensor responded sensitively to small deformations, had a high gauge factor of ~160, and underwent mechanical fracture at 30% tensile strain. In addition, we have applied the LIG sensor, which has high sensitivity, a simple manufacturing process, and good durability, to human finger motion monitoring.

Sensitive, colorimetric enzyme amplification cascade for determination of alkaline phosphatase and application of the method to an immunoassay of thyrotropin

1991 ◽  
Vol 37 (9) ◽  
pp. 1513-1518 ◽  
Author(s):  
D M Obzansky ◽  
B R Rabin ◽  
D M Simons ◽  
S Y Tseng ◽  
D M Severino ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Highly Sensitive ◽  
Wide Range ◽  
Colored Product ◽  
Enzyme Amplification ◽  
Amplification Cascade

Abstract A highly sensitive flavin adenine dinucleotide-3'-phosphate (FADP)-based enzyme amplification cascade has been developed for determining alkaline phosphatase (ALP; EC 3.1.3.1). The cascade detects ALP via the dephosphorylation of the novel substrate FADP to produce the cofactor FAD, which binds stoichiometrically to inactive apo D-amino acid oxidase (D-AAO). The resulting active holo D-AAO oxidizes D-proline to produce hydrogen peroxide, which is quantified by the horseradish peroxidase-mediated conversion of 3,5-dichloro-2-hydroxybenzenesulfonic acid and 4-aminoantipyrine to a colored product. The FADP-based enzyme amplification cascade has been used in a novel releasable linker immunoassay (RELIA) to quantify thyrotropin (TSH). In the assay, TSH is first captured onto antibody-coated chromium dioxide particles. After formation of an antibody-TSH sandwich with a dethiobiotinylated second antibody, the complex is reacted with a streptavidin-ALP conjugate. Biotin is then used to release the conjugate into solution, and ALP is quantified in an automated version of the FADP-based amplification cascade on the aca discrete clinical analyzer (Du Pont). The sensitivity of the colorimetric RELIA assay for TSH (less than 0.1 milli-int. unit/L) is comparable with that of fluorometric assays. This technology provides a way to adapt to the aca high-sensitivity immunoassays for a wide range of analytes via colorimetric detection.

scholarly journals Fiber Bragg Grating Sensors Integrated in Polymeric Foils

2010 ◽  
Vol 636-637 ◽  
pp. 1548-1554 ◽  
Author(s):  
A.F. Silva ◽  
F. Gonçalves ◽  
L.A.A. Ferreira ◽  
F.M. Araújo ◽  
P.M. Mendes ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Optical Sensors ◽  
Optical Sensor ◽  
Industrial Process ◽  
High Sensitivity ◽  
Bragg Grating ◽  
Element Analysis ◽  
Fiber Sensors ◽  
Sensor Performance ◽  
Fiber Bragg Grating Sensors

Optical sensors have hit their maturity and a new kind of systems is being developed. This paper deals with the development of a new sensing structure based on polymeric foils and optic fiber sensors, namely the Fiber Bragg Grating sensors. Sensor integration in polymeric foils, using industrial process is the proposed goal. To achieve this goal, Finite Element Analysis was used for prototype modeling and simulation. The model was subjected to loads and restraints in order to retrieve information about stress distribution and displacement of specific points. From the simulation was possible to predict the sections where the sensor should be positioned. A prototype was then fabricated using industrial processes. Tests indicate that the polymeric foil influence on the sensor performance may exist. However, the prototype was able of transferring the full deformation to the optical sensor. Moreover, the optical sensor, which is incorporated in the polymeric foil, is fully functional with high sensitivity, 0.6 picometer by microstrain, allowing deformation measurements, up to 1.2 millimeter.

Ultrahigh Sensitivity Micro-cliff Graphene Wearable Pressure Sensor Made by Instant Flash Light Exposure

Nanoscale ◽  
2021 ◽  
Author(s):  
Yachu Zhang ◽  
Han Lin ◽  
Fei Meng ◽  
Huai Liu ◽  
David Mesa ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Pressure Sensor ◽  
Biomedical Applications ◽  
Light Exposure ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Fast Response ◽  
Highly Sensitive ◽  
Ultrahigh Sensitivity ◽  
Sensitive Pressure

Wearable and highly sensitive pressure sensors are of great importance for robotics, health monitoring and biomedical applications. Simultaneously achieving high sensitivity within a broad working range, fast response time (within...

Ultra-stretchable and highly sensitive strain sensor based on gradient structure carbon nanotubes

Nanoscale ◽  
2018 ◽  
Vol 10 (28) ◽  
pp. 13599-13606 ◽  
Author(s):  
Binghao Liang ◽  
Zhiqiang Lin ◽  
Wenjun Chen ◽  
Zhongfu He ◽  
Jing Zhong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Gauge Factor ◽  
Gradient Structure ◽  
Highly Sensitive ◽  
Highly Stretchable

A highly stretchable and sensitive strain sensor based on a gradient carbon nanotube was developed. The strain sensors show an unprecedented combination of both high sensitivity (gauge factor = 13.5) and ultra-stretchability (>550%).

scholarly journals A Study of Highly Sensitive Wearable Strain Sensor Based on Graphical Sensitive Units

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jie Wang ◽  
Yi Du ◽  
Qiang Zhang ◽  
Zhu Jing ◽  
Kai Zhuo ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Real Time ◽  
Silver Nanowires ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Sine Wave ◽  
Gauge Factor ◽  
Soft Substrate ◽  
Highly Sensitive ◽  
Sensitivity Improvement

The sensitivity improvement is the choke point of the soft strain sensor’s development. This paper focuses on heightening the soft strain sensor’s sensitivity through changing the sensitive unit’s shape. The sensitive units in shape of square or sine wave with different periods were studied in this work. Silver nanowires (Ag NWs) in excellent electrical conductivity and flexible polydimethylsiloxane (PDMS) were used as sensitive nanomaterials and soft substrate. The soft strain sensor whose sensitive unit is double cycled square wave performs the highest sensitivity whose gauge factor (GF) reaches to 14763.8. Based on the high sensitivity, the sensor was applied on real-time detection of the human expression.

scholarly journals Graphene and its Derivatives-Based Optical Sensors

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao-Guang Gao ◽  
Ling-Xiao Cheng ◽  
Wen-Shuai Jiang ◽  
Xiao-Kuan Li ◽  
Fei Xing
Keyword(s):  
Optical Sensors ◽  
Low Cost ◽  
High Sensitivity ◽  
Fast Response ◽  
Cell Detection ◽  
Single Cell Detection ◽  
Sensing Applications ◽  
Wide Range ◽  
Surface Enhanced Raman ◽  
Recent Developments

Being the first successfully prepared two-dimensional material, graphene has attracted extensive attention from researchers due to its excellent properties and extremely wide range of applications. In particular, graphene and its derivatives have displayed several ideal properties, including broadband light absorption, ability to quench fluorescence, excellent biocompatibility, and strong polarization-dependent effects, thus emerging as one of the most popular platforms for optical sensors. Graphene and its derivatives-based optical sensors have numerous advantages, such as high sensitivity, low-cost, fast response time, and small dimensions. In this review, recent developments in graphene and its derivatives-based optical sensors are summarized, covering aspects related to fluorescence, graphene-based substrates for surface-enhanced Raman scattering (SERS), optical fiber biological sensors, and other kinds of graphene-based optical sensors. Various sensing applications, such as single-cell detection, cancer diagnosis, protein, and DNA sensing, are introduced and discussed systematically. Finally, a summary and roadmap of current and future trends are presented in order to provide a prospect for the development of graphene and its derivatives-based optical sensors.

scholarly journals Optical Fiber Sensors for Monitoring Railway Infrastructures: A Review towards Smart Concept

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2251
Author(s):  
Yung William Sasy Chan ◽  
Hua-Ping Wang ◽  
Ping Xiang
Keyword(s):  
Artificial Intelligence ◽  
Optical Fiber ◽  
Health Monitoring ◽  
Electromagnetic Interference ◽  
Critical Role ◽  
High Sensitivity ◽  
Optical Fiber Sensors ◽  
Fiber Sensors ◽  
Passenger Transportation ◽  
Easy Integration

Railway infrastructures have played a critical role to ensure the continuity of goods and passenger transportation in China. Under extreme loading and environmental conditions, railway structures are vulnerable to deterioration and failure, leading to the interruption of the whole transportation system. Several techniques have been used for the health monitoring of railway structures. Optical fiber sensors are the widely recognized technique due to their inherent advantages such as high sensitivity, anti-electromagnetic interference, light weight, tiny size, corrosion resistance, and easy integration and network configuration. This paper provides a state-of-the-art of optical fiber sensing technologies and their practical application in railway infrastructures. In addition, the strain transfer analysis of optical fiber sensors is described for parameter reflection. A smart concept for artificial intelligence contribution is also declared. Finally, existing and future prospects on smart concept-based optical fiber sensors for railway infrastructure are discussed. The study can provide useful guidance to understand the problems in artificial intelligence which contributed to the Structural Health Monitoring system of railway structures.

scholarly journals Study of Silicon Nitride Waveguide Platform for On-Chip Virus Detection: Prospects for COVID-19

2021 ◽  
Author(s):  
Raghi S. El Shamy ◽  
Mohamed A. Swillam ◽  
Xun Li
Keyword(s):  
Silicon Nitride ◽  
Optical Sensors ◽  
Virus Detection ◽  
High Sensitivity ◽  
Single Mode ◽  
Mass Scale ◽  
Detection Methods ◽  
Slot Waveguide ◽  
Wide Range ◽  
Strip Waveguide

Abstract This work presents a rigorous sensitivity analysis of silicon nitride on silicon dioxide strip waveguide for virus detection, focusing on COVID-19. In general, by functionalizing the waveguide surface with specific antibodies layer, we make the optical sensor sensitive only to a particular virus. Unlike conventional virus detection methods such as polymerase chain reaction (PCR), integrated refractive index (RI) optical sensors offer cheap and mass-scale fabrication of compact devices for fast and straightforward detection with high sensitivity and selectivity. Our analysis includes a wide range of wavelengths from visible to mid-infrared. We determined the strip waveguide's single-mode dimensions and the optimum dimensions that maximize the sensitivity to the virus layer attached to its surface at each wavelength. We also compared the strip waveguide to the widely used slot waveguide. Our study shows that silicon nitride strip waveguide working at lower wavelengths is the optimum choice for virus detection as it maximizes both the waveguide sensitivity (Swg) and the figure of merit (FOM) of the sensor. Furthermore, the optimized waveguide can work for a range of viruses. Balanced Mach-Zehnder interferometer (MZI) sensors were designed at different wavelengths showing high FOM at λ = 450nm ranging from 500 RIU-1 up to 1231 RIU-1 with LMZI=500 µm. Different MZI configurations were also studied and compared. Finally, edge coupling from the fiber to the sensor was designed, showing insertion loss (IL) at λ = 450nm of 4.1 dB for the design with FOM = 500 RIU-1. The obtained coupling efficiencies are higher than recently proposed fiber couplers.

Sign in / Sign up

Export Citation Format

Share Document