Query: Fiber optic sensor

title: Applications of fiber optic biochemical sensor in microfluidic chips: A review.
abstract: An overview of applications of fiber optic biochemical sensor in microfluidic chips was carried out with a specific focus on different fiber optic sensors used on chip, detection methods and biochemical application. First, the structure and sensing mechanism of different fiber optic sensors used on chip was introduced. Second, optical detection methods in microfluidic chips combined with optical fibers and the advantages and disadvantages of each method were introduced and analyzed in detail. Then, applications of fiber optic biochemical sensors in microfluidic sensor chips in detecting nucleic acids, proteins, cells, chemicals and microfluidic flow rate were classified and introduced, and different fiber optic biochemical sensors in microfluidic chip were compared. Finally, a prospect of future development of fiber optic biochemical sensor combined with microfluidic chip was addressed.

title: Ultrasensitive strain sensor based on Vernier effect improved parallel structured fiber optic Fabry Perot interferometer.
abstract: A novel parallel structured fiber optic Fabry Perot interferometer (FPI) based on Vernier effect is theoretically proposed and experimentally demonstrated for ultrasensitive strain measurement. This proposed sensor consists of open cavity and closed cavity fiber optic FPI, both of which are connected in parallel via a 3 dB coupler. The open cavity is implemented for sensing, while the closed cavity for reference. Experimental results show that the proposed parallel structured fiber optic FPI can provide an ultra high strain sensitivity of 43.2 pm/me, which is 4.6 times higher than that of a single open cavity FPI. Furthermore, the sensor is simple in fabrication, robust in structure, and stable in measurement. Finally, the parallel structured fiber optic FPI scheme proposed in this paper can also be applied to other sensing field, and provide a new perspective idea for high sensitivity sensing.

title: Simultaneous measurement of refractive index and temperature using a SPR based fiber optic sensor
abstract: A surface plasmon resonance based fiber optic sensor for simultaneous measurement of refractive index and temperature of liquid samples is proposed and experimentally demonstrated. The sensor consists of a gold coated MM SM MM optical fiber structure, whose sensitive section was partially covered with polydimethylsiloxane (PDMS) to generate two independent SPR resonance dips in the fiber transmission spectrum. One of the dips is generated by the bare gold coated fiber section whose wavelength resonance is tuned by the refractive index and temperature of the surrounding medium. The other dip that is exclusively used to monitor the temperature variations of the liquid sample, whose central wavelength at 900 nm corresponds to PDMS refractive index at 20 degC, is produced by the polymerized gold coated fiber section. The high refractive index and temperature sensitivity achieved, 2323.4 nm/RIU and 2.850 nm/degC respectively, the small size, the ease fabrication process, and the bio compatibility of the proposed device are appealing characteristics that makes it ideal for practical bio sensing applications.

title: A Non Invasive Multichannel Hybrid Fiber Optic Sensor System for Vital Sign Monitoring
abstract: In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber optic sensor system for basic vital sign monitoring. This sensor uses a novel non invasive measurement probe based on the fiber Bragg grating (FBG) The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS) The PDMS is non reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person's chest using a real time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field.

title: Novel Fiber Optic Ring Acoustic Emission Sensor
abstract: Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber optic ring sensor acoustic emission system is built based on this method. Finally, fiber optic ring acoustic emission experiments are performed. The novel fiber optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber optic ring acoustic emission sensor. In the future, this novel fiber optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

title: Surface Plasmon Resonance based fiber optic sensor for mercury detection using gold nanoparticles PVA hybrid
abstract: Fabrication of Surface Plasmon Resonance (SPR) based fiber optic sensor for mercury detection utilizing gold nanoparticles (AuNPs) PVA hybrid as sensing material is reported. Films of citrate capped AuNPs in PVA matrix are prepared and their optical properties are studied. UV vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) transmission electron microscopy (TEM) and Particle size analysis (DLS) are performed to ascertain the formation of Au NPs. Aqueous Hg 2+ sensing of citrate capped gold nanoparticles in PVA matrix are investigated. Further SPR based fiber optic sensor has been fabricated using citrate capped AuNPs PVA hybrid as sensing material. The detection limit of the proposed sensor is found to be 1 x10 6 M.

title: Overview of Fiber Optic Sensor Technologies for Strain/Temperature Sensing Applications in Composite Materials
abstract: This paper provides an overview of the different types of fiber optic sensors (FOS) that can be used with composite materials and also their compatibility with and suitability for embedding inside a composite material. An overview of the different types of FOS used for strain/temperature sensing in composite materials is presented. Recent trends, and future challenges for FOS technology for condition monitoring in smart composite materials are also discussed. This comprehensive review provides essential information for the smart materials industry in selecting of appropriate types of FOS in accordance with end user requirements.

title: U bent fiber optic SPR sensor based on graphene/AgNPs
abstract: We present a U bent fiber optic SPR sensor based on the graphene/AgNPs, combined the virtues of graphene, AgNPs and U bent fiber. By changing the laser induced time, we achieved the optimal time for the deposition of AgNPs. With the proposed graphene/AgNPs U bent fiber optic sensor, we discussed and investigated the SPR behaviors. The shifts up to 32 and 16 nm are observed respectively for the detection of 90% aqueous ethanol and 20% aqueous glucose, corresponding refractive index (RI) 1.3657 and 1.3557. The sensitivity of this proposed is calculated as 1198 nm/RIU and the response and recovery time of this U bent fiber optic sensor are respectively 3 s and 80 s. These experimental results indicate that our proposed graphene/AgNPs U bent fiber optic sensor will be expected to open new avenue for the detection in the field of medicine, biotechnology and food safety.

title: Surface plasmon resonance based fiber optic sensor for the detection of cysteine using diosmin capped silver nanoparticles
abstract: A simple green method to synthesize silver nanoparticles (AgNPs) is described where diosmin acts as reducing and capping agent. Formation of diosmin capped silver nanoparticles (Dios AgNPs) was characterized using UV vis spectroscopy, X ray diffraction, TEM, Raman imaging and FTIR analysis. Investigations on the biosensing of Dios AgNPs among various amino acids showed excellent response towards cysteine. Further an SPR based fiber optic sensor for cysteine was fabricated and its sensitivity, selectivity and limit of detection were investigated and reported. The fiber optic sensor was developed by coating a thin film of silver over the unclad core of the fiber and then coated with Dios AgNPs. The sensor has advantages of low cost of production, fast response, high selectivity and sensitivity. The sensor can be used for online monitoring and remote sensing applications.

title: A compact, flexible fiber optic Surface Plasmon Resonance sensor with changeable sensor chips
abstract: We propose and demonstrate the concept of a novel compact, flexible fiber optic Surface Plasmon Resonance (SPR) sensor based on a double pass Kretschmann type configuration, where the SPR sensor chip can be replaced for various sensing applications. Simulation and experimental results demonstrate that the proposed fiber optic SPR structure has a sensitivity to salt concentration of around 4.8 mW/ppt.