Unique Fiber Research Articles

ELECTROWRITING (CELL-LADEN) NATURAL-DERIVED POLYMER FIBRES

Orthopaedic soft tissues, such as tendons, ligaments, and articular cartilage, rely on their unique collagen fiber architectures for proper functionality. When these structures are disrupted in disease or fail to regenerate in engineered tissues, the tissues transform into dysfunctional fibrous tissues. Unfortunately, collagen synthesis in regenerating tissues is often slow, and in some cases, collagen fibers do not regenerate naturally after injury, limiting repair options. One of the research focuses of my team is to develop functional fiber replacements that can promote in vivo repair of musculoskeletal tissues throughout the body. In this presentation, I will discuss our recent advancements in electrowriting 3D printing of natural polymers for creating functional fiber replacements. This manufacturing process utilizes electrical signals to control the flow of polymeric materials through an extrusion nozzle, enabling precise deposition of polymeric fibers with sizes that cannot be achieved using conventional extrusion printing methods. Furthermore, it allows for the formation of fiber organizations that surpass the capabilities of conventional electrospinning processes. During the presentation, I will showcase examples of electrowritten microfiber scaffolds using various naturally-derived polymers, such as gelatin (a denatured form of collagen) and silk fibroin. I will discuss the functional properties of silk-based scaffolds and highlight how they exhibit restored β-sheet and α-helix structures [1]. This restoration results in an elastic response of up to 20% deformation and the ability to withstand cyclic loading without plastic deformation. Additionally, I will present our latest results on the compatibility of this technique with patterning cell-laden fiber structures [2]. This novel biofabrication process allows for the printing of biomimetic microscale architectures with high cell viability, and offers a promising approach to understanding how shear and elongation forces influence cell development of hierarchical (collagen) fibers.Acknowledgements: The author would like to thank the Reprint project (OCENW.XS5.161) and the program “Materials Driven Regeneration” (024.003.013) by the Netherlands Organization for Scientific Research for the financial support.

Ultralight aerogels via supramolecular polymerization of a new chiral perfluoropyridine-based sulfonimidamide organogelator.

Chiral and enantiopure perfluorinated sulfonimidamides act as low-molecular weight gelators at low critical gelation concentration (<1 mg mL-1) via supramolecular polymerization in nonpolar organic solvents and more heterogenic mixtures, such as biodiesel and oil. Freeze-drying of the organogel leads to ultralight aerogel with extremely low density (1 mg mL-1). The gelation is driven by hydrogen bonding resulting in a helical molecular ordering and unique fibre assemblies as confirmed by scanning electron microscopy, CD spectroscopy, and computational modeling of the supramolecular structure.

3D Fiber Network Enhanced Composite Polymer Electrolytes for All-Solid-State Sodium Batteries

All-solid-state sodium batteries (ASSBs) coupled with solid polymer electrolytes (SPEs) are considered a promising candidate for next generation energy-storage systems due to high energy-density, low-cost, and high-safety. However, the insufficient ionic conductivity and poor interfacial stability with Na metal anode of SPEs severely hinder their commercial applications. To tackle these issues, we designed a type of inorganic/polymer composite polymer electrolytes by dispersing the unique anion-trapping 3D fiber network with abundant Lewis-acid sites in the polymer matrix to realize ultra-stable ASSBs. The rich Lewis-acid sites exposed on the 3D fiber surface can grab anions to promote the dissociation of Na salts, thus significantly improve Na+ selective migrating ability. Meanwhile, the continuous channel formed between 3D fiber network and polymer matrix provides a fast Na+ transport path, further leading to high ionic conductivity. Importantly, the Na+ transference number can also be enhanced due to the anion-trapping effect, which will effectively limit anion migration, thus regulating Na+ concentration distribution for constructing stable electrolyte/Na anode interface. Based on such advantages, the resulting composite polymer electrolyte will simultaneously exhibit high ionic conductivity, considerable Na+ transference number, as well as enhanced interfacial stability toward Na metal anode. Consequently, the electrochemical properties, including discharge capacity, cycling stability, rate capability, and safety of all-solid state sodium batteries using these 3D fiber network enhanced composite polymer electrolytes will be remarkably improved. We believe that such a composite electrolyte design could provide an effective strategy for the construction of high safe and high energy-density all-solid-state rechargeable batteries. Figure 1

Waste for Waste: Interface-Intensified Durable Superhydrophilic-Superoleophobic Collagen Fiber Membrane for Efficient Separation of Cationic Surfactant-Stabilized Oil-in-Water Emulsions.

Cationic surfactant-stabilized oil-in-water emulsions pose a significant challenge in separation due to the presence of surfactants. Herein, we develop a collagen-fiber-based CFM-PMDA-TiO2 membrane with unique infiltration properties capable of efficiently separating cationic surfactant-stabilized oil-in-water emulsions by exploiting the charge-demulsification effect. The membrane exhibits superhydrophilic and submerged superoleophobic properties, making it highly suitable for separating a wide range of commercially available cationic surfactant-stabilized oil-in-water microemulsions and nanoemulsions, which demonstrates an exceptional separation efficiency as high as 99.86% and an impressive flux of up to 1436.40 L m-2 h-1. Furthermore, even after a strong subjecting of the membrane to sandpaper abrasion and a full 15 time use, the separation efficacy of oil-in-water emulsions is retained, highlighting the durability, reusability, and economic viability. We propose that these features are enabled by the electrostatic interactions triggered from pyromellitic dianhydride (PMDA) and superhydrophilic-superoleophobic membrane intensified by the TiO2 on the unique collagen fiber membrane. Outcomes emphasize the versatility and potential of our membrane in addressing emulsified oily wastewater hurdles.

Enhancing polarization maintenance and spectral filtering in negative curvature hollow-core fibers

A new design of polarization-maintaining and spectral filtering negative curvature hollow-core fiber tailored for the telecommunication bands in the near-infrared region is presented. The optical fiber, consisting of a six-tube silica structure, incorporates vertically nested tubes anchored radially by a pole structure. By contrast, standard nested tubes in the horizontal direction form the asymmetric fiber structure, which encounters birefringence. This unique fiber design not only preserves the polarization states of light but also exhibits frequency selective transmission exclusively in the vertical direction due to the pole structure. Through fiber design optimization, a transmission loss below 0.1 dB/km for spectrally filtered wavelengths is achieved, with birefringence on the order of 10−5 within the wavelength range of 1.45 µm to 1.60 µm. These results demonstrate significant improvements in terms of birefringence, distinct loss separation between horizontally and vertically polarized states, and a reduced number of spectrally filtered wavelengths compared to previously reported findings. The proposed fiber design holds untapped potential for applications requiring selective transmissions with specific polarization.

Enhancing properties and sustainability: Surface modified Cymbopogon flexuosus stem fiber for green composite materials

AbstractThe lignocellulosic fiber has distinct capacities and properties from diverse perspectives. As there is a crucial need for the development of green products, many industries are racing to identify potential fibers for their products. This work focuses first on the property enhancement using chemical modification techniques for Cymbopogon flexuosus stem fiber (CFS), which is extracted from the waste residue of an oil industry. The chemically treated fibers resulted in higher cellulose (77.35%) and lower hemicellulose‐lignin contents (8.36% and 14.5%), which favors composite manufacturing. Morphological analysis on the fiber surface through scanning electron microscope (SEM) and atomic force microscope (AFM) evidenced the surface was rough, and a single fiber tensile test reveals an average tensile strength of 635 ± 4.5 MPa. Further x‐ray diffraction examination verified the existence of semi‐crystalline cellulose with a size of 14.32 nm and a higher crystallinity index of 55.17%. Secondly, to explore fiber prospective qualities against the commercially available bio‐composite, epoxy resin‐based composites were prepared by varying the weight and length of fiber reinforced. The surface‐modified CFS epoxy composite has the highest tensile strength (77.71 MPa), tensile modulus (5.26 Gpa), flexural strength (87.4 MPa), flexural modulus (1.85 GPa), hardness (64 HRRW), and impact strength (9.31 J/cm2). The thermogravimetric analyses were evaluated to assess their weight loss under heat influence. Tensile fractography was also investigated to establish the structure–property relationship between the composite and fiber. Thus, unique fiber was identified as an ecologically benign and economically viable raw material to build lightweight green materials for industrial applications.Highlights Studies explores the potential of CFSF, which is typically an industrial waste. Chemical modification reveals the enhancement of properties. Identifies optimum parameters that enhance composite properties. This aligns with the broader trend of sustainable and green manufacturing.

Treatment of Stainless Steel Rinse Waters Using Non-Dispersive Extraction and Strip Dispersion Membrane Technology.

The extraction of Fe(III), Cr(III), and Ni(II) from stainless steel rinse water using non-dispersive extraction and strip dispersion membrane technology was carried out in a microporous hydrophobic hollow-fibre module contactor. The fibres were of polypropylene, whereas the organic extractant DP8R (bis(2-ethylhexyl) phosphoric acid) diluted in ExxsolD100 was used as the carrier phase. The rinse water containing the three elements was passed through the tube side, and the pseudo-emulsion formed by the organic phase of DP8R in Exxol D100 and an acidic strip solution were passed through the shell side in a counter-current operation; thus, a unique hollow fibre module was used for extraction and stripping. In non-dispersive extraction and strip dispersion technology, the stripping solution was dispersed into the organic membrane solution in a vessel with an adequate mixing device (impeller) designed to form strip dispersion. This pseudo-emulsion was circulated from the vessel to the membrane module to provide a constant supply of the organic phase to the membrane pores. Different hydrodynamic and chemical variables, such as variation in feed and pseudo-emulsion flow rates, strip phase composition, feed phase pH, and extractant concentration in the organic phase, were investigated. Mass transfer coefficients were estimated from the experimental data. It was possible to separate and concentrate the metals present in the rinse water using the non-dispersive extraction and strip dispersion technique.

Variations in the Vascular Bundle and Fiber Structure during the Stem Development of Rattan (Calamus caesius Blume)

Calamus caesius is one of the most well-known commercial climbing palm species across the world. A comprehensive understanding of the growth-dependent variation in microstructure and polymer distribution can provide fundamental information to guide its end-use applications. In this study, we investigated the age-wise characteristics of rattan stems and the ultrastructure of fibers using electron microscopy, light microscopy, and FTIR. The results showed that the frequency of vascular bundles with a diameter of 0.55∼0.62 mm in C. caesius was 3.49∼3.97 pieces/mm2. The diameter and length of the metaxylem vessel were 0.32∼0.34 mm and 2.86∼3.00 mm, respectively. Cellulose, lignin, xylan, and HCA are mainly concentrated in the fiber sheath of vascular bundles. The distribution of major polymers in positions other than the top was relatively stable. The tissue proportion of parenchyma, xylem, and phloem did not differ significantly at different positions. The proportion of fibers from 22.27%∼25.33% showed significant differences. The fiber length was 1.43∼1.76 mm, and the diameter was 10.78∼12.63 μm. During the growth process of the rattan stem, the secondary wall of fiber cells continued to accumulate inward towards the cell cavity from 2 to 6 layers. The unique fiber properties and stable vascular bundle composition of C. caesius may have potential in fields such as composite materials or renewable energy.

Flax fiber-chitosan biocomposites with tailored structure and switchable physicochemical properties

A facile and sustainable synthesis of unique flax fiber composites (FFCs) is reported, where raw flax fiber (FFR) was immobilized with variable chitosan content. FFCs were structurally characterized via TGA, XRD, SEM analysis, and spectroscopy (IR, NMR, and Raman mapping). Physicochemical characterization of FFCs enabled estimation of the point-of-zero-charge (PZC), solvent swelling at variable pH. Dye adsorption with Rose Bengal (RB) and Methylene Blue (MB) afforded characterization of the surface chemistry of the materials. This contribution study is a first reported example that highlights the unique structure-property relationships of FFC materials and the role of electrostatic interactions between the pristine fiber substrate and chitosan. FFCs with incremental chitosan content display the following trends: (i) greater solvent swelling at variable pH (350 % for FFCs and ca. 100 % for FFR and commercial absorbents), (ii) two-fold enhanced adsorption of RB (FFC 0.5 to FFC 2.0) and (iii) 1.5-fold decreased adsorption of MB (FFC 2.0 to FFC 0.5). The unique “switchable” sorption properties of the FFCs toward solvent and dyes was revealed upon facile and noncovalent immobilization of chitosan onto FFR. The sustainable composites reported herein offer a potential adsorption-based technology suitable for filter-based applications in “smart textiles” to biomedical sorbents for wound healing.

High power pulse delivery over a short distance through an all-solid anti-resonant microstructured optical fiber at [formula omitted] wavelength

We propose an all-solid silica-based, large mode area (LMA) anti-resonant microstructured optical fiber through which optical pulses of high-power can be delivered at the near mid-infrared wavelength range. Anti-resonant guidance of light has been achieved in the silica-based microstructured geometry by embedding 15 high-index solid cylinders in a low-index background matrix that essentially creates a node-less negative curvature cladding region surrounding the low-index core. The fiber geometry has been optimized in such a way that a large mode area of ∼2000μm2 is achieved for the fundamental mode with a loss in the order of 0.04 dB/m at 2μm wavelength. Moreover, the higher-order modes are at least one order of magnitude lossy than the fundamental mode at the operating wavelength. The optimized fiber structure has exhibited that a pulse of peak power as high as 1 kW and width of 2.2 ps can be sustained without any alteration in shape and degradation of power when the pulse is delivered through the fundamental mode over the proposed fiber length of 25 m. Hence, this proposed unique silica-based all-solid anti-resonant fiber structure is suitable for short-distance delivery of high-power pulses at 2μm wavelength with effective single mode separation.

Hetero-structured composite cathodes by electrospinning with high CO2-poisoning tolerance for solid oxide fuel cells

The sluggish oxygen reduction reaction (ORR) kinetics significantly hinder the development of intermediate temperature solid oxide fuel cells (IT-SOFC). Herein, a heterostructure composite fibers cathode composed of Ba0.9La0.1Co0.7Fe0.2Nb0.1O3-δ and Sm0.2Ce0.8O2-δ (BLCFN-SDC fibers) has been co-synthesized by electrospinning method, which exhibited excellent electrochemical activity, CO2 tolerance and long-term stability. The polarization resistance (Rp) of BLCFN-SDC fibers cathode at 700 °C is only 0.050 Ω cm2, much lower than those of single-phase BLCFN fibers (0.069 Ω cm2) and BLCFN powders (0.073 Ω cm2). Such improvement can be attributed to the extended three-phase boundary (TPB) and more exposed oxygen reduction reaction (ORR) active sites. Besides, the unique fibers structure provides continuous charge transport paths, which improve its conductivity. Furthermore, BLCFN-SDC fibers exhibits excellent CO2 tolerance in high concentration CO2 atmosphere, benefited from the low CO2 adsorption characteristics and stability of SDC. The results suggest that such heterostructure fibers cathode with excellent ORR activity and CO2 durability might provide a novel method to design efficient catalysts for SOFCs and other energy conversion devices.

Damage evolution model and failure mechanism of continuous carbon fiber-reinforced thermoplastic resin matrix composite materials

As a new composite material with high strength, toughness, and heat resistance, the continuous fiber-reinforced polyaryl ether sulfone ketone (PPESK) thermoplastic resin matrix composite (CFRP) has a wide temperature range, which is attributed to the complex temperature sensitivity of the matrix. The failure evolution characteristics under different conditions are not clear yet, which significantly limits its development and application to high-precision equipment. In this work, in order to deeply explore the full three-dimensional (3D) multi-scale multi-physics damage evolution mechanism of the CFRP over a wide temperature range, macroscale cross-temperature stretching/bending experiments, computer tomography (CT) scanning, and microscale scanning electron microscopy (SEM) are performed to effectively capture the overall damage morphology and local fiber/matrix damage failure characteristics of the material. The results show that the reinforcement with continuous fibers increases the tensile strength of the CFRP by 14–45 times and its bending strength by 2–6 times compared to those of the PPESK matrix in the cross-temperature domain. Moreover, the main failure mechanism of the CFRP in the cross-temperature domain is matrix crushing and fiber fracture at room temperature and fiber fretting slip and matrix viscous flow at high temperatures. This further explains the deformation mechanism of the CFRP, which can maintain its stability at high temperatures (low elongation at break: 1%–1.2%). The unique trans-temperature regional energy evolution and continuous fiber reinforcement of the material matrix resin PPESK lay the synergic stability of the high temperature performance and damage morphology of the CFRP. In particular, a cell model is constructed to further reveal the damage evolution characteristics of the matrix, fiber, and interface of the CFRP at the micro-scale. Combined with the failure mode theory and the performance degradation mechanism of composite materials, the temperature influence factor is introduced to formulate a multi-scale full 3D temperature-dependent damage evolution constitutive model of the CFRP over a wide temperature range. The constitutive model of the CFRP is incorporated in finite element software, and the simulation results are compared with the experimental ones for validation. The results show that the model developed in this work can effectively characterize the complex mechanical damage morphology and progressive failure characteristics of the CFRP over a wide temperature range.

A unique fiber laser processing of Z-A composite under dry, gas, liquid, and solid environments: A competitive ablation efficiency followed by surface analysis

Compared to monolithic ceramics, the Z-A composite exhibits distinct behavior when stressed. It serves to impede the propagation of the crack's endpoint and retains its structural integrity. This intriguing quality makes it a choice for any high-stress supportive application that necessitates robustness, particularly in the medical industry. However, the laser processing of Z-A is quite sophisticated than monolithic ceramic due to its different thermal properties and varying energy absorption rates that are contingent upon the reinforcing material and matrix. The current investigation outlines a unique approach called FLSDM (fiber laser step-down milling) to create the squircle pattern on Z-A (uniquely by laser) for possible implications as a bone scaffold. The present work has also paid close attention to the effectiveness of laser processing factors (LPFs) that might affect the efficacy of ablation under the disparate states of environments like dry, liquid, gas, and solid. Moreover, this article asserts experimental inquisitions for an extensive comparative study on a short-pulse laser ablation efficiency and laser-treated surface (LTS) analysis under disparate environments. The study examines various aspects such as laser-induced surface morphology, crack behavior, crystal structure, bonding pattern, and phase transformation. The current FLSDM methodology exhibits its suitability by offering a possibility for the adoptable configuration on the Z-A to meet scaffold requirements.

Highly nonlinear tellurite photonic crystal fiber for supercontinuum generation: Design and quantitative performance analysis

This research study proposes a unique photonic crystal fiber (PCF) consisting of a solid core and a hexa-spiral shape, using tellurite as the background material. The proposed PCF exhibits numerous significant optical guiding properties, such as nonlinearity, dispersion, effective index, effective mode area, etc. Simulated findings from COMSOL Multiphysics v5.5 confirm that the PCF can achieve high nonlinearity and zero-dispersion at 1650 nm. The base material is tellurite, which has a significant nonlinear refractive index (RI) of 5.11 × 10−19 m2 W−1. The resultant wave has a bandwidth of 562.65 nm when pumped at a wavelength of 1650 nm. Additionally, a continuum can be produced by pumping at 1500 and 1550 nm. The designed PCF can generate a broad spectrum of supercontinuum with a pulse duration of 200 fs and 10 kW input power. Here is also performed measurements and inspections on the impact of higher-order Taylor series dispersion coefficients, pulse width, input power, etc. The proposed PCF has many potential applications, including nonlinear optics, high dispersion characteristics, infinitely single-mode fibers, high wattage beam transmission, particle trapping, and sensing. To address these applications, here is used COMSOL Multiphysics to generate data, such as propagation constants, attenuations, effective area, and fields, which were used by Optisystem. To the best of our knowledge, this is the first investigation to verify the performance of our designed PCF in Optisystem, for modeling signal transmission for supercontinuum generation and Raman shift.

In-situ precipitation of ultrafine Mg2Ni particles in Mg-Ni-Ag metal fibers and their hydrogen storage properties

The intermetallic compound Mg2Ni shows improved hydrogen de-/absorption kinetics and a lower desorption temperature compared to pure Mg. However, the coarse Mg2Ni phase and its limited hydrogenation capacity restrict the application of the Mg2Ni alloy. In this study, an attempt was made to prepare Mg-Ni alloy fibers with a higher Mg content and a well-distributed Mg2Ni catalytic phase using the melt extraction (ME) method, and a unique metallic glass fiber was formed. With pre-annealing at 350 °C in a vacuum, uniformly dispersed Mg2Ni nanoparticles are in-situ formed, the phase transition is revealed to be metallic glass → Mg6Ni → Mg2Ni + Mg. About 1.5 wt% of hydrogen can be absorbed by the Mg-Ni fibers at 50 °C, and it is completely released in 8.8 min at 225 °C. Both the JMA and Kissinger models were utilized to accurately characterize the dehydrogenation activation energy, and the values of 90.4 and 95.8 kJ/mol were obtained, respectively. The hydrogen desorption process involves two distinct processes, the decomposition of Mg2NiH4 nanoparticles and MgH2 hydride in sequence, with dehydrogenation enthalpy changes of 64.5 and 78.2 kJ/mol, respectively. After hydrogen absorption and desorption cycles, a loose structure forms around the Mg2Ni nanoparticles. This structure serves as an efficient nucleation site for hydrides and provides diffusion paths for H atoms.

Advancements in Performance Optimization of Electrospun Polyethylene Oxide-Based Solid-State Electrolytes for Lithium-Ion Batteries.

Polyethylene oxide (PEO)-based solid-state electrolytes for lithium-ion batteries have garnered significant interest due to their enhanced potential window, high energy density, and improved safety features. However, the issues such as low ionic conductivity at ambient temperature, substantial ionic conductivity fluctuations with temperature changes, and inadequate electrolyte interfacial compatibility hinder their widespread applications. Electrospinning is a popular approach for fabricating solid-state electrolytes owing to its superior advantages of adjustable component constitution and the unique internal fiber structure of the resultant electrolytes. Thus, this technique has been extensively adopted in related studies. This review provides an overview of recent advancements in optimizing the performance of PEO solid-state electrolytes via electrospinning technology. Initially, the impacts of different lithium salts and their concentrations on the performance of electrospun PEO-based solid-state electrolytes were compared. Subsequently, research pertaining to the effects of various additives on these electrolytes was reviewed. Furthermore, investigations concerning the enhancement of electrospun solid-state electrolytes via modifications of PEO molecular chains are herein detailed, and lastly, the prevalent challenges and future directions of PEO-based solid-state electrolytes for lithium-ion batteries are summarized.

Fabric‐Based Smart Metasurface

AbstractFabric presents several advantages including excellent flexibility, lightweight, bend resilience, breathable properties, and significant price advantage compared to commercial low‐loss boards, providing a natural advantage for the preparation of flexible electromagnetic (EM) devices and wearable systems. A key challenge when using fabric as the substrate for active devices lies in the contradiction between the poor high‐temperature resistance of fabric materials and the welding requirements for semiconductor components, leading to a significant gap between flexible and traditional RF technology. Benefiting from the unique fiber structure of fabric materials, a conjecture is creatively proposed for integrating lumped components onto fabric substrates through the sewing method and successfully verifying its validity and stability. As an application, a fabric‐based smart metasurface (FSM) is designed and realized for potential portable EM protection applications. The proposed FSM has the advantage of good flexibility, low cost, and a high strength‐to‐weight ratio. By carefully designing the structure of the metasurface and also the sensing module, large‐angle stable EM performance is achieved, and the FSM can function well even under highly distorted conditions. The proposed method and product inspire promising application aspects in wearable electronics, portable EM protection, and related flexible RF technologies.

Investigation of the Tensile Properties in Continuous Glass Fiber–Reinforced Thermoplastic Composite Developed Using Fused Filament Fabrication

Abstract Continuous fiber–reinforced thermoplastic composites are gaining acceptance in the manufacturing sector. However, the production constraints of intricate designs, the difficulty of using unique fiber alignment, and the expensive moldings make their usage inadequate. This investigation attempts to produce composites using continuous glass fiber as filler material and three distinct polymers, acrylonitrile butadiene styrene, polylactic acid, and polyethylene terephthalate glycol, utilizing an indigenously built nozzle attachment with the fused filament fabrication (FFF) process. Furthermore, scanning electron microscopy (SEM) images were used to elucidate the interface performance. The experimental results showed that the tensile strength of glass fiber–reinforced composites was 218 to 241 % greater than that of just thermoplastic specimens when the printing raster direction was 0° and 35 to 45 % lower when the printing raster orientation was 90°. Furthermore, SEM findings revealed that the tensile stress was very low and had bad interface behavior when the printing raster orientation was 90°. FFF has more adaptability for fiber reinforcement because of its meticulous orientation and good dispersal capabilities for the additively manufactured part, which may be directly used as the final product. The fiber content and its interfacing with base material are critical technical specifications for the composites.

Simulation of Trenched Coreless Silica Fiber Sensor for Refractive Index Measurement

Coreless silica fiber has garnered a lot of attention in the field of sensors. Nevertheless, the limitation of conventional and unique coreless silica fiber sensors such as complex simulation, and high fragility of its physical structure needs to be considered. This work presents a simulation of a new coreless silica fiber design in a form of a trenched coreless silica fiber sensor to overcome these limitations. To optimize the sensor’s design, the trench depth was changed in the range of 0 μm to 50 µm at a fixed trench width of 50 μm. The change in analyte refractive index ranging from 1.3000 RIU to 1.4000 RIU was performed to evaluate the simulated sensing performance which showed that the increase in trench depth improved the sensor’s sensitivity with 50 μm being the trench depth at which the highest sensitivity was recorded. Later, the results obtained was compared to the closest in term of design which is the standard coreless fiber. Overall, the trenched coreless silica fiber design provided better sensitivity and is highly capable as of has a new refractive index sensor with an estimated sensitivity of up to 6.62726x10-7, higher than the simulated standard coreless fiber sensor with that of 2.22053x10-7.

Auto-Lectin Dotcoding by Two Octopuses: Rapid Analysis of Fluorescence-Labeled Glycoproteins by an 8-channel Fully-Automatic Bead Array Scanner with a Rolling-Circle Detector.

Protein glycosylation is a crucial factor that must be evaluated in biological pharmaceuticals. The glycoform profile of a protein can vary depending on the conditions of the cultivation, purification process, and the selection of a host cell. Lectin microarrays are reliable bioanalytical methods used in the early phases of bioprocesses for the detection of glycosylation. The concept of a fully automated glycan detection with a bead array has been previously reported; however, no simple system has been constructed on fluorescence-based detection using a microarray. Here, we present a fully automated detection system equipped with a novel fluorescence detector for a 13-lectin bead array with a single tip. The lattice-like arrangement of a set of fibers proximate to the tip of the light emitting diode and photomultiplier tube detector minimized the noise caused by the reflection of incident light on the plastic capillary tip and bead. A unique rolling-circle fiber unit with quadruple lattices stacked in two layers realizes the 8-parallel automeasurement with a drastic reduction in scanning time and machine size. The 8-glycan profiles obtained automatically within 25 min were identical with those obtained with the conventional lectin microarray after overnight incubation. The signals obtained were represented as lectin dotcodes. Therefore, autolectin dotcoding assisted by the twin 8 legs named as "detection and irradiation octopuses" may be a rapid glyco-evaluation system during the production and development of biopharmaceuticals.