Strong Field Research Articles

Detection of production relevant deviations in paint sprays

AbstractSpray painting is still a poorly manageable process due to the complex interaction of physical, chemical and environmental influences like turbulent air flows, strong electrostatic fields, complex viscosity of paints and paint booth conditions. Consequently, many important properties of the painted film, like thickness, color, surface structure and the efficiency of the process are not controllable in an adequate manner, despite the enormous economic ramifications of poor quality control in high volume applications, such as in the automotive industry. This study shows how novel, online spray monitoring can instantaneously generate characterizing quantities from the spray to detect harmful deviations in the process. In this study, several minute changes have been experimentally imposed on a paint system, such as changed paint viscosity or pigmentation, deviations in air flow and paint flow rates, and defective or used and worn equipment parts. It will be shown that all these deviations lead to features which allow a clear distinction from the intact and reference cases. Additionally, it is shown that most of the deviations, if not detected, would have led to quality issues of the paint coating.

Overall photosynthesis of hydrogen peroxide with redox-active catechol moiety by modulating charge behavior of polydopamine-coated engineered carbon nitride

Photocatalytic production of hydrogen peroxide (H2O2) offers an environment-friendly and sustainable route. However, low efficiency and undesirable by-products hinder its large-scale application. A heterostructure (PDA/SCN) by in situ polymerization dopamine on edge functionalized carbon nitride (SCN) has been designed to integrate photoredox and photocatalytic production of hydrogen peroxide with revisable transformation between catechol and o‑benzoquinone. Benefiting from the strong built-in electric field, efficient photoinduced charge separation is disclosed to facilitate the autoxidation of redox-active catechol moiety. In addition, functional groups (–NH2) on the heterostructure, as an interfacial H-bond modulation site, are conductive to optimize the O2 activation and subsequent formation of the key intermediate *OO. Moreover, a homemade gas-solid-liquid triphase flow cell using PDA/SCN photocatalyst with improving mass transfer process has been constructed, which shows a high H2O2 generation of 1.32 mM h–1 under visible light (λ ≥ 420 nm) without using any sacrificial reagent. This photocatalytic system provides a new guidance of efficient photocatalyst design for the synthesis of H2O2 without using any sacrificial reagent.

Electric Fields in Polymeric Systems.

Polymer-based electronic devices are limited by slow transport and recombination of newly separated charges. Built-in electric fields, which arise from compositional gradients, are known to improve charge separation, directional charge transport, and to reduce recombination. Yet, the optimization of these fields through the rational design of polymeric materials is not prevalent. Indeed, polymers are disordered and generate nonuniform electric fields that are hard to measure, and therefore, hard to optimize. Here, we review work focusing on the intentional optimization of electric fields in polymeric systems with applications to catalysis, energy conversion, and storage. This includes chemical tuning of constituent monomers, linkers, morphology, etc. that result in stronger molecular dipoles, polarizability or crystallinity. We also review techniques to characterize electric fields in polymers and emerging processing strategies based on electric fields. These studies demonstrate the benefits of optimizing electric fields in polymers. However, rational design is often restricted to the molecular scale, deriving new pendants on, or linkers between, monomers. This does not always translate in strong electric fields at the polymer level, because they strongly depend on the monomer orientation. A better control of the morphology and monomer-to-polymer scaling relationship is therefore crucial to enhance electric fields in polymeric materials.

Phase separation of planetary ices explains nondipolar magnetic fields of Uranus and Neptune

The Voyager spacecraft discovered that the ice giants Uranus and Neptune have nondipolar magnetic fields, defying expectations that a thick interior layer of planetary ices would generate strong dipolar fields. Stanley and Bloxham showed that nondipolar fields emerge if the magnetic field is only generated in a thin outer layer. However, the origin and composition of this dynamo active layer has so far remained elusive. Here, we show with ab initio computer simulations that a mixture of H2O, CH4, and NH3 will phase separate under the pressure-temperature condition in the interiors of Uranus and Neptune, forming a H2O-dominated fluid in the upper mantle and a CH4-NH3 mixture below. We further demonstrate that with increasing pressure, the CH4-NH3 mixture becomes increasingly hydrogen depleted as it assumes the state of a polymeric C-N-H fluid. Since the amount of hydrogen loss increases with pressure, we propose that the C-N-H fluid forms a stably stratified layer. The magnetic fields are primarily generated in an upper layer that is H2O-rich, homogeneous, convective, and electrically conducting. Under these assumptions, we construct ensembles of models for the interiors of Uranus and Neptune with the Concentric MacLaurin Spheroid method. We demonstrate that the phase separation of the solar-type H2O-CH4-NH3 mixture leads to models that match the observed gravity field and to layer thicknesses that are compatible with magnetic field measurements.

High-Performance and Environmentally-Friendly Bulk-Wave-Acoustofluidic Devices Driven by Lead-Free Piezoelectric Materials.

Bulk-wave-acoustofluidic devices provide strong acoustic fields and high device efficiency, thereby offering high-throughput capability when processing biological samples. Such devices are typically driven by lead zirconate titanate (PZT) transducers, which contain a high content of lead, inevitably resulting in environmental and biocompatibility issues. Replacing PZT with lead-free piezoelectric materials in various ultrasonic devices is considered challenging mainly due to the inferior piezoelectric properties lead-free materials possess compared to those of PZT. In this study, through both experiments and numerical simulations, it is demonstrated that the performance of the bulk-wave-acoustofluidic devices driven by (Bi,Na)TiO3-BaTiO3-(Bi,Na)(Mn,Nb)O3 (BNT-BT-BNMN) can match that of PZT-driven devices at low power and is superior at intermediate power. It is found that the low acoustic impedance and the weak transverse mode in BNT-BT-BNMN compensate for the inferior piezoelectric properties at low power. The fact that the BNT-BT-BNMN devices outperform at intermediate power is consistent with the superior performance of the Mn-doped BNT-based piezoelectric materials compared to PZT at high power. Perfect focusing on 5- -diameter polystyrene particles at a flow rate of up to 10 mL min-1 is achieved using the BNT-BT-BNMN device at input power of 1W.

Acoustic enhancement and weak signal detection based on quasibound states in the continuum

Acoustic signal detection is important in several fields of research. However, realizing weak-signal detection remains a challenge. Recently, the bound state in continuum (BIC) has attracted considerable attention because of its ultrahigh quality-factor (Q-factor) and strong field enhancement. In this study, we achieved two Fabry–Perot BICs (bonding and anti-bonding BICs) in a coupled-resonator system and a mirror-induced BIC in a single-resonator system. And the acoustic enhancement from quasi-BICs of the coupled-resonator system and single-resonator system was investigated in the simulation. Compared to the coupled-resonator system, the amplification performance of the single-resonator system was better and verified in the experiment. The experimental results agreed with the numerical results, and the maximum pressure magnification was approximately 28×. Furthermore, the single-resonator system enhanced the weak harmonic signal, weak periodic impulse signal, and weak modulated signal in the presence of strong background noise, making signal detection much easier. We believe that this work provides a new method to realize weak signal detection based on acoustic enhancement.

Study on the corona aging characteristics of KH570-modified nano-Al(OH)₃ cycloaliphatic epoxy resin in hygrothermal environments

Cycloaliphatic epoxy(CE) resin may experience insulation degradation and pose a threat to the safe operation of equipment when used in high-temperature and high-humidity environment. Therefore, to enhance the corona aging resistance of CE under harsh conditions, this study incorporated γ-methacryloxypropyltrimethoxysilane-modified (KH570) nano-Al(OH)₃ with varying content into the CE. The samples were subjected to corona aging tests under different hygrothermal conditions. The corona aging characteristics of CE in high-temperature and high-humidity environments were analyzed using scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), resistivity, and dielectric loss measurements before and after modification. The results indicate that as humidity increases, the unmodified samples develop pores and cracks on the surface, which leads to an increased water absorption rate and internal hydrolysis. However, with the increase in filler content, the water absorption channels on the sample surface decrease, effectively suppressing chemical moisture absorption and maintaining the stability of the internal chemical structure. Among the various filler contents, the effect was most pronounced at 3%wtCE. Under 65 % RH conditions, the volume/surface resistivity increased by 27.28 % and 26.9 %, respectively, the leakage current decreased by 64.85 %, while the dry and wet breakdown voltages increased by 9.3 kV and 6.85 kV, respectively, and the dielectric loss variation with humidity was reduced. Compared to the unmodified material, KH570-modified nano-Al(OH)₃ has significantly improved the insulation and aging resistance properties of the material under hot and humid corona aging conditions. This study provides a reference for improving the performance of epoxy resins under high temperature, high humidity, and strong electric field conditions.

Van der Waals NbOCl2 Nanodisks for Enhanced Second-Harmonic Generation.

Niobium oxide dichloride (NbOCl2), a van der Waals crystal, exhibits exceptional second-harmonic generation (SHG) with high conversion efficiency, making it a promising candidate for on-chip quantum light sources, photon modulators, and sensors. To increase its suitability for integrated photonic systems, it is crucial to explore strategies for further improving optical nonlinear conversion efficiency. In this article, dielectric metasurfaces are employed to enhance SHG from patterned NbOCl2 nanodisks. By precisely tuning their geometric parameters to achieve optical resonance near the excitation wavelength, a remarkable 25-fold enhancement in second-harmonic emission at 400 nm is achieved in nanodisks compared to the unpatterned thin film. The strong field enhancement within the NbOCl2 nanodisks at nanophotonic resonances contributes to the observed increase in SHG. This work offers an effective strategy for boosting SHG in van der Waals NbOCl2 thin films, paving the way for the development of efficient nonlinear optical components in integrated nanophotonics.

Trapping light in air with membrane metasurfaces for vibrational strong coupling

Optical metasurfaces can manipulate electromagnetic waves in unprecedented ways at ultra-thin engineered interfaces. Specifically, in the mid-infrared (mid-IR) region, metasurfaces have enabled numerous biochemical sensing, spectroscopy, and vibrational strong coupling (VSC) applications via enhanced light-matter interactions in resonant cavities. However, mid-IR metasurfaces are usually fabricated on solid supporting substrates, which degrade resonance quality factors (Q) and hinder efficient sample access to the near-field electromagnetic hotspots. Besides, typical IR-transparent substrate materials with low refractive indices, such as CaF2, NaCl, KBr, and ZnSe, are usually either water-soluble, expensive, or not compatible with low-cost mass manufacturing processes. Here, we present novel free-standing Si-membrane mid-IR metasurfaces with strong light-trapping capabilities in accessible air voids. We employ the Brillouin zone folding technique to excite tunable, high-Q quasi-bound states in the continuum (qBIC) resonances with our highest measured Q-factor of 722. Leveraging the strong field localizations in accessible air cavities, we demonstrate VSC with multiple quantities of PMMA molecules and the qBIC modes at various detuning frequencies. Our new approach of fabricating mid-IR metasurfaces into semiconductor membranes enables scalable manufacturing of mid-IR photonic devices and provides exciting opportunities for quantum-coherent light-matter interactions, biochemical sensing, and polaritonic chemistry.

Multiple Fano resonances in all-dielectric porous array structures

High Q metasurfaces play an important role in fields such as high-sensitivity sensing and nonlinear optics due to their strong localized electromagnetic field enhancement. Although ultra-high Q resonance has been developed in the field of optics, it is still a challenging task due to the loss of dielectric materials, design and fabrication of nanostructures. In this paper, we have designed an all-dielectric symmetric perforated array structure that supports multiple Fano resonances within the 0–1 THz range and realizes the anapole mode through this array perforation structure. By calculating the phase difference between different modes at the resonance frequencies, we explain the mechanism of the formation of resonance-coupled BIC. The Q-factors of the three modes have been calculated, where the highest Q-value can be up to 2703, it is excited by the MQ. Then, we analyzed the sensing performance and the highest sensitivity can reach 27,000 nm/RIU. Since the metasurface always maintains c_4v symmetry and mirror symmetry, all three resonances are polarization independent. The proposed metasurfaces can be applied to light-matter interactions, enhanced nonlinear response, and sensing.

High Quality-Factor All-Dielectric Metacavity for Label-Free Biosensing.

High sensitivity and high quality-factor are crucial for achieving outstanding sensing performance in photonic biosensors. However, strong optical field confinement and high light-biomolecule interactions on photonic surfaces are usually contradictory and challenging to satisfy simultaneously. Here, a distinctive configuration for addressing this issue is reported: embedding a nanophotonic metasurface inside a micro vertical cavity as a meta-channel (metacavity) biosensor. The analyte solution serves as the cavity medium, thereby maximizing the light-analyte interaction. Simulation validation is conducted to optimize the metacavity with high structural robustness and remarkable optical and sensing properties. Large-scale low-cost metacavity biosensors are realized by combining anodic aluminum oxide template technique and wafer bonding. Experimentally, the metacavity biosensor demonstrates a notable quality-factor (maximum 4140) and high bulk refractometric sensitivity (450nmRIU-1), resulting in an unprecedented figure-of-merit (1670 RIU-1). Moreover, the metacavity biosensor achieves high surface sensitivity, together with a detection-limit of 119 viral copies mL-1 for label-free severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus sensing, revealing remarkable performance in both bulk and surface sensing.

Experimental Realization of Subwavelength Spoof Plasmonic Bound States in the Continuum and Ultra‐Sensitive Detection

AbstractOptical bound states in the continuum (BICs) lies in side the continuum and coexists with extended waves, but it remains perfectly confined without any radiation. This unique property of BICs has led to numerous applications, such as highly surface‐sensitive and spectrally sharp resonances for photonic biosensors. However, it remains challenging to experimentally realize the BICs in a single‐particle system, especially for subwavelength structures. This study presents the existence of optical BICs in a subwavelength metallic microstructure, and quasi‐BICs are observed experimentally in a waveguide system with only a single optimized aluminum meta‐particle. This plasmonic BICs is resulting from the destructive interference of two localized surface plasmon modes. Benefiting from its strong localized field confinement and substrate‐free merit of BICs, the experimentally measured quality factor (Q‐factor) of this transmission dip reach to 273. Additionally, this meta‐particle is experimentally verified to show a good sensitivity for both solids and liquids through the spectral shift of the BICs caused transmission dip. This finding extends the optical BICs to a subwavelength scale and opens practical application opportunities for ultrasmall‐quantity detection of biochemical substances.

Ion‐Permeable Electrospun Scaffolds Enable Controlled In‐Vitro Electrostimulation Assay of Myoblasts

AbstractIn‐vitro models are fundamental for studying muscular cell contractility and for wide‐screening of therapeutic candidates targeting skeletal muscle diseases, owing to their scalability, reproducibility, and circumvention of ethical concerns. However, in‐vitro assays permitting reliable electrical stimulation of cell contractile activity still require technological development. Here, a novel approach to electrically stimulate differentiated muscular cell contractility is reported exploiting the ionic conductivity and mechanical flexibility of 3D nanofibrous scaffolds. The electrospun poly(L‐lactide‐co‐caprolactone) scaffold allowed for C2C12 murine myoblasts horizontal elongation and myotubes formation. Scaffold porosity enables high ionic conductivity and strong electric field generation, orthogonally oriented to the scaffold surface. Electrically induced cell contractility is determined with atomic force microscopy (AFM) enabling real‐time monitoring of scaffold vibrations in liquid environment. Differentiated cell actuation is found to be linearly correlated to current amplitude and number of current stimuli. Integrating the 3D nanofibrous scaffolds with real‐time AFM monitoring provides highly accurate in‐vitro assays for biomedical research. The induction of electric fields orthogonal to the scaffold surface allows for accurately mimicking the excitation‐contraction coupling mechanism observed in native skeletal muscle tissue. This work paves the way for the quantitative study of muscular cell dynamic behavior and physiology, further evaluating therapy effectiveness for muscular pathologies.

A Three‐Phase Omnidirectional Wireless Charger Based on Segmented Arc‐Shaped Coupler With High Anti‐Rotation Offset Feature for AUVs

ABSTRACTWhen the autonomous underwater vehicle (AUV) is charged by wireless charging technology (WCT), the coupler will be misalignment due to the impact of marine environment factors, which can lead to the weak stability of the system output. Besides, the electromagnetic field generated by the coaxial coil is concentrated in the center of the AUV hull, and the strong electromagnetic field may interfere with the normal operation of the power electronic equipment inside the AUVs. To address the above problems, this paper proposes a novel coupler with high anti‐offset and suppression of the central magnetic field of the AUVs. The coupler is composed of a three‐phase segmented arc‐shaped transmitter coils and a cylindrical receiver coil. The coupler can implement the suppression of the AUV central magnetic field and the promotion of anti‐rotation offset feature under the omnidirectional uniform magnetic field control method. To better adapt the proposed coupler and meet the battery charging requirements, a three‐phase wireless charging topology with a relay is designed, which can acquire the smooth transition between the two charging modes without constructing the wireless communication between two sides and detecting the state of charge (SOC). Finally, to verify the feasibility of the proposed scheme, a 1‐kW AUV wireless charging prototype is built. The experimental results indicate that the maximum output power fluctuation rate of the system is 1.1% in the case of the full‐angle rotation offset.

Interfacial [S─Cu─C] Bonds Induced π-d Electron Coupling Toward Modulating Charge Transfer for Efficient Solar Water Oxidation.

Regulating the interfacial electric field to achieve rapid charge transfer is crucial for superior photoelectrochemical water splitting. Herein, the ultra-thin hydrogen-substituted graphdiyne (HsGDY) is precisely assembled on the surface of CdS nanorod array (Cu-CdS-HsGDY) by an in situ polymerization strategy. The strong π-d electron coupling is aroused by the delocalized π electrons of HsGDY and the delocalized d electrons of CdS through the interfacial [S─Cu─C] bonds. The strong interfacial electric field can effectively promote the charge localization distribution and reduce the charge transfer resistance. The optimized Cu-CdS-HsGDY photoanode obtain a photocurrent density as high as 4.83 mA cm-2 at 1.23 V versus reversible hydrogen electrode in neutral electrolyte solution under AM 1.5G illumination, which is 6.8 times that of the pristine CdS. Moreover, the photoanode maintains an initial photocurrent density of 84% within 4 h without any assistance of sacrificial agents, which is a rather competitive performance of similar sulfide photoanodes. The mechanism of strong π-d electron coupling on interfacial charge transfer and surface reaction kinetics is investigated by transient spectroscopy measurements, density functional theory calculation, and finite element simulation analysis. This work provides new insights into designing a reasonable interface structure to regulate charge transfer for achieve efficient PEC water splitting.

ExaGRyPE: Numerical general relativity solvers based upon the hyperbolic PDEs solver engine ExaHyPE

ExaGRyPE describes a suite of solvers and solver ingredients for numerical relativity that are based upon ExaHyPE 2, the second generation of our Exascale Hyperbolic PDE Engine. Numerical relativity simulations are crucial in resolving astrophysical phenomena in strong gravitational fields and are fundamental in analyzing and understanding gravitational wave emissions. The presented generation of ExaGRyPE solves the Einstein field equations in the standard CCZ4 formulation under a 3+1 foliation and focuses on black hole space-times. It employs a block-structured Cartesian grid carrying a higher-order Finite Difference scheme with full support of adaptive mesh refinement (AMR), it facilitates massive parallelism combining message passing, domain decomposition and task parallelism, and it supports the injection of particles into the grid as static data probes or as moving tracers. We introduce the ExaGRyPE-specific building blocks within ExaHyPE 2, and discuss its software architecture and compute-n-feel.For this, we formalize the creation of any specific astrophysical simulation with ExaGRyPE as a sequence of lowering operations, where a few abstract logical tasks are successively broken down into finer and finer tasks until we obtain an abstraction level which can directly be mapped onto a C++ executable. The overall program logic is fully specified via a domain-specific Python interface, we automatically map this logic onto a more detailed set of numerical tasks, subsequently lower this representation onto technical tasks that the underlying ExaHyPE engine uses to parallelize the application, before eventually the technical tasks in turn are mapped onto small task graphs including the actual astrophysical PDE term evaluations, initial conditions, boundary conditions, and so forth. These can be injected manually by the user, or users might instruct the solver on the most abstract user interface level to use out-of-the-box ExaGRyPE implementations. We end up with a rigorous separation of concerns which shields ExaGRyPE users from technical details and hence simplifies the development of novel physical models. We present the simulations and data for the gauge wave, static single black holes and rotating binary black hole systems, demonstrating that the code base is mature and usable. However, we also uncover domain-specific numerical challenges that need further study by the community in future work.

Orientation-independent quantification of macromolecular proton fraction in tissues with suppression of residual dipolar coupling.

Quantitative magnetization transfer (MT) imaging enables noninvasive characterization of the macromolecular environment of tissues. However, recent work has highlighted that the quantification of MT parameters using saturation radiofrequency (RF) pulses exhibits orientation dependence in ordered tissue structures, potentially confounding its clinical applications. Notably, in tissues with ordered structures, such as articular cartilage and myelin, the residual dipolar coupling (RDC) effect can arise owing to incomplete averaging of dipolar-dipolar interactions of water protons. In this study, we demonstrated the confounding effect of RDC on quantitative MT imaging in ordered tissues can be suppressed by using an emerging technique known as macromolecular proton fraction mapping based on spin-lock (MPF-SL). The off-resonance spin-lock RF pulse in MPF-SL could be designed to generate a strong effective spin-lock field to suppress RDC without violating the specific absorption rate and hardware limitations in clinical scans. Furthermore, suppressing the water pool contribution in MPF-SL enabled the application of a strong effective spin-lock field without confounding effects from direct water saturation. Our findings were experimentally validated using human knee specimens and healthy human cartilage. The results demonstrated that MPF-SL exhibits lower sensitivity to tissue orientation compared with , , and saturation-pulse-based MT imaging. Consequently, MPF-SL could serve as a valuable orientation-independent technique for the quantification of MPF.

Viscous heating and instabilities in the partially ionized solar atmosphere

Abstract In weak magnetic fields (≲ 50 G), parallel and perpendicular viscosities, mainly from neutrals, may exceed magnetic diffusivities (Ohm, Hall, ambipolar) in the middle and upper chromosphere. Ion-driven gyroviscosity may dominate in the upper chromosphere and transition region. In strong fields (≳ 100 G), viscosities primarily exceed diffusivities in the upper chromosphere and transition region. Parallel and perpendicular viscosities, being similar in magnitude, dampen waves and potentially compete with ambipolar diffusion in plasma heating, potentially inhibiting Hall and ambipolar instabilities when equal. The perpendicular viscosity tensor has two components, ν1 and ν2, which differ slightly and show weak dependence on ion magnetization. Their differences, combined with shear, may destabilize waves, though magnetic diffusion introduces a cutoff for this instability. In configurations with a magnetic field B having vertical (bz = Bz/|B|) and azimuthal (by = By/|B|) components, and a wavevector k with radial ($\hat{k}_x=k_x/|{\bf k}|$) and vertical ($\hat{k}_z=k_z/|{\bf k}|$) components, parallel viscosity and Hall diffusion can generate the viscous-Hall instability. Gyroviscosity further destabilizes waves in the upper regions. These findings indicate that the solar atmosphere may experience various viscous instabilities, revealing complex interactions between viscosity, magnetic fields, and plasma dynamics across different atmospheric regions.

Additive and subtractive hybrid manufacturing assisted by femtosecond adaptive optics

Advanced micro–nano devices commonly require precise three-dimensional (3D) fabrication solutions for pre-designing and integrating 0D to 3D configurations. The additive–subtractive hybrid manufacturing strategy dominated by femtosecond laser direct writing has become an increasingly interesting technical route for material processing. In this study, a novel approach termed femtosecond adaptive optics-assisted hybrid manufacturing was proposed, which integrates subtractive (femtosecond laser ablation) and additive (two-photon polymerization) fabrication. In this hybrid manufacturing method, the introduction of adaptive optics offers parallel direct writing and wide-area material processing capabilities. To demonstrate the validity of the hybrid approach, on-chip surface plasmon polariton waveguides with strong sub-wavelength field confinement and enhanced functionality were successfully fabricated. In comparison with the terahertz-wave devices fabricated based on the focused ion beam technique, the functional tests in terahertz near-field microscopy show a rival performance fabricated with our hybrid approach. Besides, our cost-effective solution also dramatically reduces the fabricating time of excitation regions by a factor >16. Our work provides a new inspiration in integrated photonics.

An ultra-low loss balloon-type single stress-applying optical fiber refractive index sensor

In the field of refractive index (RI) sensing, macro-bending sensors have been widely studied for their advantages of low loss and easy fabrication. Here, an ultra-low loss balloon-type single stress-applying fiber (SSAF) sensor is demonstrated. The sensor is manufactured by splicing SSAF between two single-mode fibers (SMFs) in a balloon shape. The sensing of different RI solutions is realized based on the strong evanescent field characteristics generated by the SSAF with a stress-sensitive zone during bending. Compared with other macro-bending sensors, the RI sensitivity of the proposed sensor with a bend diameter of 0.95 cm has been doubled, reaching up to 387.09 nm/RIU in the range of 1.3308–1.3628, with a resolution of 0.0013 and a loss of 2.22 dB. The sensor has a compact structure, low processing difficulty, strong reproducibility, and low loss, which provides a new way for the development prospects of biomedical science, environmental monitoring, food safety, etc.