Spiral Fiber Research Articles

FBG Hydrogen Sensor Based on Pd87–Ni13/Pd4–Ag1 Thin Film and Femtosecond Laser Ablation

A novel laser machined spiral microstructure fiber Bragg grating (FBG) hydrogen sensor and coated with composite sensing film is presented. The sensor probes are sputtered with Pd/Ni and Pd/Ag film, respectively. Experimental results exhibit that a pitch 60 μm FBG with double spiral microstructures, coated with 520 nm Pd/Ni and Pd/Ag film has hydrogen gas sensitivity in air of 13 pm/%H and 25 pm/%H, respectively. The laser-ablated spiral microstructured probes with composite films shown greater sensitivity compared with standard FBG probes with similar coating. The optimum testing temperature (50 °C) enhanced the sensitivity and repeatability of the probes.

Investigation of flow dynamics of thin viscous films down differently shaped fibers

The flow dynamics of a thin viscous film down on a fiber is associated with a variety of industrial applications. In this paper, we experimentally investigate the flow behaviors of a thin film falling on differently shaped fibers. For a spiral fiber, flow behaviors show three typical flow regimes as the cylindrical fiber, which indicates the isolated regime, Rayleigh–Plateau regime, and convective regime. However, the transition process of various fiber shapes is distinctively different. Unlike the cylindrical fiber, flow on a spiral fiber exhibits a wider range of flow rate in the Rayleigh–Plateau regime, which is helpful for the precise control of flow patterns in a relatively stable regime. We further quantitatively investigate three important characteristic parameters of flow dynamics of a spiral fiber, i.e., bead velocity, thickness, and spacing. Results reveal that a thin film on a spiral fiber has a higher bead velocity, larger bead thickness, and larger bead spacing. Our findings provide important insights for understanding flow dynamics of a thin viscous film down on shaped fibers, which may also inspire coating flow control methods in various applications.

Highly Stretchable Strain Sensor With Spiral Fiber for Curvature Sensing of a Soft Pneumatic Gripper

This paper proposes a flexible strain sensor based on the principle of resistance sensing to estimate the curvature information of the soft pneumatic gripper. The proposed sensor mainly includes a spiral conductive fiber and a central elastic base pillar. The conductive fiber is made of the stretchable elastomer DragonSkin-30 and multi-walled carbon nanotubes (MWCNTs) mixture, and a customized platform is designed to perform extrusion for fabrication. Three essential factors of the substrate, the fiber diameter, and the mixing ratio of MWCNTs have been investigated to improve the sensitivity and strain range of the sensor. Ecoflex-10 with excellent tensile properties has been selected to make the elastic base pillar. The stretchability, linearity, and service life of the sensor were improved by optimizing the spiral arrangement of conductive fibers through experiments. The proposed approach for manufacturing and assembly offers the advantages of easy implementation, convenient integration, and low cost. The electrical performances of the prototyped spiral sensor have been characterized, and it can reach an excellent strain range of up to 400% with linearity of 98%. The prototype has been integrated on the outer surface of a soft pneumatic gripper and well reflected the diameters of the unknown objects with an error of 3.99% through calibration and grasp-release experiments.

Structural and mechanical model of spiral fiber-reinforced concrete

Orthotropic concrete reinforcement is the addition of spiral fibers to concrete. Finite element modeling is used to study the influence of the spiral fiber geometry on the physical and mechanical properties of concrete. Based on the numerical and experimental research, the proposed mathematical model of fiber-reinforced concrete shows that the composite with the desired properties and structure is obtained with the optimum parameters of the spiral fiber namely 20-30 mm length, 5 mm diameter, and 1.5 mm distance between turns.

Fiber Optic-Based Thermal Integrity Profiling of Drilled Shaft: Inverse Modeling for Spiral Fiber Deployment Strategy.

The current state of practice to interpret the thermal integrity profiling (TIP) data of drilled shaft is the so-called effective radius method. It uses the concrete pouring log and average temperature to construct a relationship between temperature distribution and effective radius that can be used to reconstruct a drilled shaft model. While this effective radius method is computationally inexpensive and has good operationality, it is not good at predicting the dimensions and shape of shaft defects. Upgrading the sensor used in conventional TIP from thermocouples/thermal wires to fiber optic sensors, the spatial resolution of the measured temperature will be enhanced. By using the newly proposed spiral fiber deployment strategy, we can improve the reconstruction of shaft defects in the integrity testing of drilled shafts. The corresponding inverse modeling of defected shaft reconstruction for spiral deployment is proposed in this paper based on the temperature distribution pattern that is learned from forward modeling. Through inverse modeling, the details of defects in drilled shafts can be reconstructed numerically. An analysis of the results shows that the prediction by inverse modeling has good agreement with the forward modeling set up initially. This work helps the evolution of the TIP from the nondestructive testing stage to the quantitative nondestructive evaluation stage.

Development of ZIF-67 derived hollow multishelled structures Co3O4/carbon nanomaterials as spiral solid-phase microextraction fiber for superior capture of fifteen PAHs

Here, a unique spiral-solid phase microextraction (S-SPME) fiber using ZIF-67 derived hollow multishelled structures Co3O4/carbon nanomaterials (HoMS-Co3O4/C) as the coating was designed for superior capture of trace polycyclic aromatic hydrocarbons (PAHs). The ligand 2-methylimidazole of ZIF-67 was replaced twice with 2,5-dihydroxyterephthalic acid and followed by pyrolysis to obtain the material with an unique hollow double-shelled structure. The formation of the hollow structure can be explained by the Ostwald ripening. Fifteen PAHs, four brominated flame retardants (BFRs), and seven endocrine chemicals (EDCs) were used to investigate the extraction performance of HoMS-Co3O4/C coated S-SPME fiber. The spiral fiber displayed higher selectivity for PAHs compared with BFRs and EDCs. The methods had low detection limits (0.002–2.680 μg L−1), wide linear ranges (0.005–1000 μg L−1), and good reproducibility (0.7–10.7%, fiber to fiber). In addition, the S-SPME fiber demonstrated excellent enrichment ability and extraction efficiency for PAHs compared with commercial SPME fibers, it might since there were strong π-π stacking force, hydrophobic interaction between analytes and HoMS-Co3O4/C coating, also the HoMS coating and the spiral fiber could greatly increase the contact area between adsorbent and target compounds. Finally, the HoMS-Co3O4/C coated S-SPME fiber had been further adopted to detect fifteen PAHs in environmental water samples successfully.

The Formin Fmn2b Is Required for the Development of an Excitatory Interneuron Module in the Zebrafish Acoustic Startle Circuit.

The formin family member Fmn2 is a neuronally enriched cytoskeletal remodeling protein conserved across vertebrates. Recent studies have implicated Fmn2 in neurodevelopmental disorders, including sensory processing dysfunction and intellectual disability in humans. Cellular characterization of Fmn2 in primary neuronal cultures has identified its function in the regulation of cell-substrate adhesion and consequently growth cone translocation. However, the role of Fmn2 in the development of neural circuits in vivo, and its impact on associated behaviors have not been tested. Using automated analysis of behavior and systematic investigation of the associated circuitry, we uncover the role of Fmn2b in zebrafish neural circuit development. As reported in other vertebrates, the zebrafish ortholog of Fmn2 is also enriched in the developing zebrafish nervous system. We find that Fmn2b is required for the development of an excitatory interneuron pathway, the spiral fiber neuron, which is an essential circuit component in the regulation of the Mauthner cell (M-cell)-mediated acoustic startle response. Consistent with the loss of the spiral fiber neurons tracts, high-speed video recording revealed a reduction in the short latency escape events while responsiveness to the stimuli was unaffected. Taken together, this study provides evidence for a circuit-specific requirement of Fmn2b in eliciting an essential behavior in zebrafish. Our findings underscore the importance of Fmn2 in neural development across vertebrate lineages and highlight zebrafish models in understanding neurodevelopmental disorders.

Enhancement of OAM and LP modes based on double guided ring fiber for high capacity optical communication

This article introduced a double guided ring-based spiral photonic crystal fiber (S-PCF) supporting both the orbital angular momentum (OAM) and linear polarization (LP) mode simultaneously with the efficient transmission. The outcomes exhibition that the designed S-PCF have good optical features such as less confinement loss (4.05342 × 10−12 dB/m for the EH9,1 mode), better mode quality and ISO (up to 98.87% and 126 dB, respectively), supported a decent amount of modes which is numerically 64 OAM and 6 LP modes, maintaining the large refractive index differences (>10-4) of all the eigenmodes, and a relatively flat dispersion variation (0.0743 ps/km-nm for the EH1,1 mode). Also, we obtained the crosstalk less than −12 dB and the power fraction is approximately 93%-99% of the S-PCF. All the optimizing properties are obtained using the full-vector finite element method (FEM) and also the perfectly matched layer (PML) as a boundary condition. Thus, the above mentioned optimizing propagation characteristic based S-PCF has effective applications like reliable long-distance communication into the space division multiplexing (SDM) process of the large-capacity fiber communication systems.

Revolution-assisted direct writing of highly controllable spiral graphene fibers with ultrasensitive photoelectric response

Spiral graphene-based fibers have enticing advantages in high breakage elongation and stable electrical property during the tensile process, but the conventional manufacturing methods are complicated and hard to produce in large quantities. Herein, we demonstrated a facile and effective revolution-assisted direct writing strategy for controllably constructing spiral graphene fiber, with a spinneret revolving along a revolution axis in the coagulation bath. The resulting spiral graphene fiber displayed excellent mechanical and electrical stability even when stretched 20000 times at 320% elongation, as well as easily regulatable radius (0.1–3.5 mm) and pitch (1–8 mm) through changing the revolution radius (distance between spinneret and revolution axis) and the motion (horizontal movement and rotation speed) of the spinneret, respectively. Moreover, functionalized with TiO2 nanoparticles, the obtained spiral composite fiber featured a highly sensitive photoelectric response to its tiny deformation, implying a great potential for liquid micro-vibration detection. This study provides a new strategy to fabricate controllably spiral graphene-based fibers with high properties.

Uniaxial performance of circular hybrid fibre-reinforced lightweight aggregate concrete columns

To investigate the compressive performance of fibre-reinforced concrete columns, 20 circular columns with a consistent size of Φ250 × 750 mm were tested, considering different concrete types, steel spiral spacing, fibre types, and volumetric fibre fractions. Polypropylene fibres prevented the initial cracking and premature spalling of the cover more obviously than carbon fibres. The compressive strength of spirally confined lightweight aggregate concrete (LWAC) was improved to 1.45 times the unconfined strength, and the fibre-reinforced LWAC exhibited a greater enhancement in the compressive strength provided by the confining pressure than the plain LWAC. The incorporation of both single carbon fibres and hybrid carbon–polypropylene fibres enhanced the ductility of LWAC columns, while the polypropylene fibres exhibited an insignificant influence on the compressive properties of LWAC. Identical volumetric fractions of the two fibres contributed more significantly to the ductility of LWAC. Concerning the improved peak strain and residual strength, a confinement model of fibre-reinforced LWAC that accounted for the superposition of individual confinement effects, including lateral reinforcement and fibres, was proposed and compared with the experimental results. The predictions exhibited better agreement with the experimental curves than the existing typical models.

Bioinspired 3D helical fibers toughened thermosetting composites

Thanks to the special helical structure, natural composites such as shell, wood, and bone have remarkable toughness, strength and damage tolerance. Herein, a bioinspired spiral nylon monofilament/epoxy composite is developed, which is a representative example of helical fiber/thermosetting composites. The relationship between toughness and strength of composites was studied by controlling parameters of the helical fibers. As a result, the impact resistance is regularly increased by the increase of pitch and the decrease of helix fiber angle. With a single-layer addition, the impact toughness of composites is increased by 150% without decreasing the mechanical strength and that is increased by 450% in the case of three-layer addition. The proposed toughening mechanism was verified by finite element analysis and dynamic mechanical analysis, which including 3D stress dispersion, the interlocking fibrous building interface, and energy absorption capacity of viscoelastic spring polymer. Furthermore, the toughness and strength of the composites is improved by 310% in single layer via surface modification of spiral fibers. The introduction of the three-dimensional spiral structure into the composite is demonstrated to be a unique strategy to overcome the trade-off between toughness and strength of high-performance composite materials.

Numerical investigation of spiral photonic crystal fiber (S-PCF) with supporting high order OAM modes propagation for space division multiplexing applications

This article proposes a spiral designed photonic crystal fiber (S-PCF) that supports 14 orbital angular momentum (OAM) modes for signal transmission and possess very low nonlinear coefficient and flat dispersion and it could assess for space division multiplexing applications. The core material of the proposed fiber is silicon because it shows excellent transmittance, low thermal response, chemically inert etc. The dispersion variations of 20–110 ps nm−1 km−1 for all OAM-modes are exhibited at 1.00 μm wavelength. In addition, overall dispersion distinction among all modes is under 10 ps nm−1 km−1. Besides, $$TM_{0,1}$$ and $$TE_{0,1}$$ modes are better in dispersion for its flat and low dispersion. Moreover, the nonlinear coefficient is very low that is 2.10 W−1 km−1 for $$EH_{5,1}$$ at 2.50 µm wavelength and the investigated confinement loss is always below than $$10^{ - 5}$$ dB m−1. In addition these basic optical parameters, few other properties such as numerical aperture and the effective-area are also computed. Considering all noble features, this proposed S-PCF is encouraging to be utilized in extra-capacity, large bandwidth and high-volume for optical fiber communication systems.

Bio-Inspired Lotus-Fiber-like Spiral Hydrogel Bacterial Cellulose Fibers.

Hydrogel materials with high water content and good biocompatibility are drawing more and more attention now, especially for biomedical use. However, it still remains a challenge to construct hydrogel fibers with enough strength and toughness for practical applications. Herein, we report a bio-inspired lotus-fiber-mimetic spiral structure hydrogel bacterial cellulose fiber with high strength, high toughness, high stretchability, and energy dissipation, named biomimetic hydrogel fiber (BHF). The spiral-like structure endows BHF with excellent stretchability through plastic deformation and local failure, assisted by the breaking-reforming nature of the hydrogen bonding network among cellulose nanofibers. With the high strength, high stretchability, high energy dissipation, high hydrophilicity, porous structure, and excellent biocompatibility, BHF is a promising hydrogel fiber for biomedicine. The outstanding stretchability and energy dissipation of BHF allow it to absorb energy from the tissue deformation around a wound and effectively protect the wound from rupture, which makes BHF an ideal surgical suture.

A Dual Guided Modes Regions Spiral Winding Optical Fiber Supporting 24 OAM Diffraction Patterns and 4 LP Modes

A Dual Guided Modes Regions Spiral Winding Optical Fiber Supporting 24 OAM Diffraction Patterns and 4 LP Modes

Possibility of Using the Spiral Single Mode Optical Fiber for Dispersion Compensation

This research show the possibility of using the Anisotropy of spiral single mode optical fiber for compensation the main three types (material,waveguide,and polarized) of dispersion.it is also study the effect of energies mutual transformation of optical pulsed signals that carried by orthogonal waves (HEe11) and (HEo11) on the generation the chromatic and polarized dispersions and inter symbol distortions of signals.an example of polarized modal dispersion compensation is gives.

Altered expression of genes regulating inflammation and synaptogenesis during regrowth of afferent neurons to cochlear hair cells.

The spiral ganglion neurons constitute the primary connection between auditory hair cells and the brain. The spiral ganglion afferent fibers and their synapse with hair cells do not regenerate to any significant degree in adult mammalian ears after damage. We have investigated gene expression changes after kainate-induced disruption of the synapses in a neonatal cochlear explant model in which peripheral fibers and the afferent synapse do regenerate. We compared gene expression early after damage, during regeneration of the fibers and synapses, and after completion of in vitro regeneration. These analyses revealed a total of 2.5% differentially regulated transcripts (588 out of 24,000) based on a threshold of p<0.005. Inflammatory response genes as well as genes involved in regeneration of neural circuits were upregulated in the spiral ganglion neurons and organ of Corti, where the hair cells reside. Prominent genes upregulated at several time points included genes with roles in neurogenesis (Elavl4 and Sox21), neural outgrowth (Ntrk3 and Ppp1r1c), axonal guidance (Rgmb and Sema7a), synaptogenesis (Nlgn2 and Psd2), and synaptic vesicular function (Syt8 and Syn1). Immunohistochemical and in situ hybridization analysis of genes that had not previously been described in the cochlea confirmed their cochlear expression. The time course of expression of these genes suggests that kainate treatment resulted in a two-phase response in spiral ganglion neurons: an acute response consistent with inflammation, followed by an upregulation of neural regeneration genes. Identification of the genes activated during regeneration of these fibers suggests candidates that could be targeted to enhance regeneration in adult ears.

Smart T-Shirt Based on Wireless Communication Spiral Fiber Sensor Array for Real-Time Breath Monitoring: Validation of the Technology

In this paper, we present the design and the validation of a new smart textile developed for real time monitoring of human breath. The smart textile is a wearable stretching T-shirt featuring an array of six contactless and non-invasive sensors placed on human’s thoraco-abdominal walls. The wireless sensors communicate quasi-simultaneously the data to a detection base station through Bluetooth protocol. The sensor is composed of a spiral shaped multi-material fiber antenna with a central frequency at 2.4 GHz connected to a compact Bluetooth transmitter. The sensors are integrated on the stretchable T-shirt without compromising the user’s comfort. The sensing mechanism of the system is based on the shift of the central frequency of the spiral fiber antenna induced by the deformation of the thorax and the abdomen during the breath. As a consequence, the breathing pattern is obtained through the received signal strength indicator recorded by a portable detection base station. With the sensor array integrated into a T-shirt, we demonstrate the feasibility assessment for monitoring breathing of seven volunteers in seating and standing positions. Using an array of sensors strategically placed on the T-shirt provides a more reliable approach to detect interpretable breathing patterns by sensing the movement of the abdomen and the thorax at the same time. Using a commercial spirometer as a standard reference, we assessed the validity of breathing parameters (ie; expiration and inspiration times, breathing period, and breathing rate) measured with the T-shirt. Based on Bland-Altman statistical analysis, a good agreement between textile-based sensors and the standard reference was obtained. We were able to show that the smart T-shirt could detect breathing patterns and pauses in breathing, which could be very useful to monitor sleep apnea and clinical monitoring of patients.

Ultrasensitive temperature sensor based on a urethane acrylate-coated off-axis spiral long period fiber grating

We propose and experimentally demonstrate an ultra-high sensitivity fiber-optic sensor to measure temperature changes in order to establish a high-precision temperature model in the bio-fermentation process. The proposed sensor based on off-axis spiral long-period fiber grating (OAS-LPFG) is fabricated in a single mode fiber (SMF) by arc discharge technology. This kind of grating is distinguished in the refractive index (RI) modulation, geometry changes, and shear stress of a spiral structure. Because the RI of the urethane acrylate is close to that of the SMF cladding and has a high thermo-optic coefficient, the resonant wavelength of the OAS-LPFG dip has a high sensitivity to the temperature measurement. The response of the OAS-LPFG to environmental RI is analyzed by full vector complex coupling mode theory. In the experiment, the temperature sensitivity of the proposed sensor can be reached ∼-108.69 nm/°C over a range of 25.0 °C to 25.5 °C. Compared with other all-fiber-based temperature sensors, the sensor has higher sensitivity.

MMP-14 (MT1-MMP) Is a Biomarker of Surgical Outcome and a Potential Mediator of Hearing Loss in Patients With Vestibular Schwannomas

Improved biomarkers are needed for vestibular schwannoma (VS), the most common tumor of the cerebellopontine angle, as existing clinical biomarkers have poor predictive value. Factors such as tumor size or growth rate do not shed light on the pathophysiology of associated sensorineural hearing loss (SNHL) and suffer from low specificity and sensitivity, whereas histological markers only sample a fraction of the tumor and are difficult to ascertain before tumor treatment or surgical intervention. Proteases play diverse and critical roles in tumorigenesis and could be leveraged as a new class of VS biomarkers. Using a combination of in silico, in vitro, and ex vivo approaches, we identified matrixmetalloprotease 14 (MMP-14; also known as MT1-MMP), from a panel of candidate proteases that were differentially expressed through the largest meta-analysis of human VS transcriptomes. The abundance and proteolytic activity of MMP-14 in the plasma and tumor secretions from VS patients correlated with clinical parameters and the degree of SNHL. Further, MMP-14 plasma levels correlated with surgical outcomes such as the extent of resection. Finally, the application of MMP-14 at physiologic concentrations to cochlear explant cultures led to damage to spiral ganglion neuronal fibers and synapses, thereby providing mechanistic insight into VS-associated SNHL. Taken together, MMP-14 represents a novel molecular biomarker that merits further validation in both diagnostic and prognostic applications for VS.

Structural performance of optimised spirally deformed steel fibre

The capability of steel fibres in stress transferring across the cracked sections (bridging effect) could be employed to enhance the concrete role (especially in tension zones) in the overall load bearing capacity of Reinforced Concrete (RC) members. However, the structural applications of Fibre Reinforced Concrete (FRC) is limited mainly due to the poor performance of existing fibres on the market (softening response). The continuous pullout load decay, i.e. softening response, cannot result in a major contribution of fibres to the ultimate load bearing capacity of RC members. In this paper, the structural contribution of an optimised spirally deformed steel fibre engineered by the authors possessing hardening response in normal concrete is examined experimentally. To this end, a structural testing programme consists of two sets of RC beams, i.e. shear-critical and flexure-critical, is designed such that the shear and flexural contribution of the spiral fibre can be assessed individually. Various experiment parameters are considered in the testing programme. The test results reveal that such a fibre could be employed as partial/full replacement for conventional reinforcement in RC beams. A shear design equation for RC beams incorporating the new fibre is also proposed.