Emergent geometric order characterizes social insect nests, exemplified by paper wasps, which collectively build arrays of hexagonal cells to optimize space and mechanical stability. These arrays contain topological defects in the form of nonhexagonal cells, which disrupt the order of the nest. A disclination like a single pentagon or heptagon modifies angular geometry and introduces curvature, whereas adjacent pentagon-heptagon pairs form dislocations that retain planarity by offsetting angular mismatch at the cost of translational order. Unlike the malleable wax of honeybee combs, the rigid materials like plant fibers used by wasps limit structural remodeling, making such defect management more challenging. Here, we show the migration of dislocations through a sequence of discrete steps involving splitting into different types of disclinations. Defects propagate via local rearrangements of walls and vertices, analogous to star-triangle transformations and node release events that conserve topological charge, as confirmed by Burgers circuits. The shift was likely intended to promote hexagonal cell formation, with a secondary aim of driving the defect to the boundary. This was not achieved because subsequent nest growth displaced the boundary farther away from the defect region. Our results suggest that wasps achieve global architectural coherence through local geometric transformations that preserve topology, enabling decentralized construction under material constraints.

We show that the orbital angular momentum (OAM) of electrons is dynamically induced by circularly polarized phonons. The induced OAM originates from the adiabatic evolution in which electrons acquire Berry phase formulated in terms of the Berry curvature encoded in phonon displacement space. By introducing a tight-binding model with p orbitals on a honeycomb lattice, we show a microscopic picture that ionic rotations modulate orbital overlaps of electrons, and calculate the generated OAM, whose sign depends on phonon chirality. We then construct an effective model for valley phonons with different phonon pseudoangular momenta and identity their distinct intervalley-scattering channels. Our model obeys the selection rule between phonons and electrons with the orbital degree of freedom. Extending this framework to d-orbital electrons, our model is applied to describe the induced OAM in monolayer transition metal dichalcogenides. Our results reveal a direct orbital generation mechanism that emerges even in materials with weak spin-orbital coupling, opening a new promising way for orbitronics applications.

Curved waveguide displays could avoid the thickness and weight penalties incurred when planar waveguides are embedded in ophthalmic lenses. However, to our knowledge, no exact design framework has previously been available for spherical waveguides with two-dimensional pupil expansion. We introduce closed mode families for planar, cylindrical, and spherical waveguides based on exact jump maps. These modes make overlapping guided-beam generations single-valued and turn incoupler and expander gratings into analytical translations in mode space. Residual aberrations arise only during image extraction at the outcoupler. For moderate spherical curvatures below 3 dpt, corresponding to radii above 175 mm, non-sequential ray tracing yields angular errors below 1 arcmin for monochromatic imaging to an 8 mm pupil over a 22° diagonal field, comparable to visual acuity. The framework therefore establishes a route toward thin, prescription-compatible, truly glasses-like augmented-reality displays.

This paper presents a Mach-Zehnder interferometer (MZI)-based vector bending sensor employing a four-core fiber and experimentally demonstrates its sensing performance. The sensor is fabricated by fusion splicing 1 mm long multimode fiber (MMF) segments to both ends of the four-core fiber, forming an interferometric structure with a well-defined resonance dip for curvature measurement. Due to the asymmetric arrangement of the fiber cores, the effective refractive index distribution changes with the bending orientation, thereby enabling vector bending sensing. Experimental results demonstrate that, within the curvature range of 0.497-0.642m-1, the maximum bending sensitivities along the two principal sensing axes reach 91.342 and 78.716nm/m-1, respectively, while the corresponding minimum sensitivities are 19.290 and 21.218nm/m-1. The sensor exhibits minimum sensitivity when the bending direction is perpendicular to the core-array axis and maximum sensitivity when it is parallel to the core-array axis. As the bending orientation varies from 0° to 360°, the sensitivity exhibits a periodic angular response. In addition, the temperature sensitivity of the sensor is measured to be 0.077 nm/°C. The proposed sensor features a simple fabrication process, good directional discrimination capability, and good repeatability, making it a promising candidate for vector bending sensing applications.

Whiplash injuries due to rear impact vehicle collisions remain a significant global concern, with females facing a disproportionately higher risk of permanent medical impairment compared to males. Current rear impact testing predominantly uses 50th percentile male dummies, such as the BioRID II, which are not representative of the female population. A 50th percentile male dummy roughly corresponds to a 90th-95th percentile female in stature and mass, which appear to render whiplash protection systems less effective for women. In preparation for future investigation of car models with known differences in whiplash injury risk between female and male occupants, the development of an upgraded average size female BioRID prototype, denoted P50F_V2, was initiated to further improve the first female BioRID prototype. The aim was to better represent female properties by reducing upper torso stiffness and improving spinal curvature, as well as simplifying the H-point position measurement and refining the external contours of the head, hands and feet. The dynamic response of the upgraded prototype was evaluated with regard to rear impact sled tests, comprising female volunteers close to the 50th percentile female size. Overall, the dynamic response of the upgraded prototype showed improvements, in particular, the T1 rearward angular displacement better matched the female volunteer response corridors. Although the biofidelity of the upgraded prototype leaves room for further improvement, it is deemed sufficient to provide an understanding of the differences in dynamic response between female and male occupants in rear impacts. Overall, the upgraded BioRID P50F, used as a complement to the BioRID II, is a significant step towards sex-inclusive crash testing.

High-strength aluminum tubular extrusions are being increasingly used in lightweight automotive structures; however, the significant springback caused by elastic recovery after bending compromises geometric accuracy. In roll-based bending processes, springback behavior is affected by multiple process parameters, which necessitates a systematic investigation and a simulation-based springback compensation approach. In this study, the springback behavior of high-strength aluminum tubular extrusions subjected to roll-based bending was investigated via finite-element analysis. The effects of feeding displacement, roller rotational speed, and internal mandrel application on springback were comparatively evaluated. Springback was quantitatively assessed based on the displacement and angular deviation after unloading, and the influence of each process parameter was analyzed. Based on the results, variations in roller rotational speed had a negligible effect on springback, whereas feeding displacement was identified as the dominant governing factor under all investigated conditions. Although internal mandrel application reduced stress levels and mitigated wrinkle formation, the overall springback tendency remained dependent on feeding displacement. Based on these findings, a simulation-based stroke compensation approach was proposed, and a compensation window satisfying the target curvature radius of R = 150 mm was numerically identified under the investigated finite-element conditions.

Background/Objectives: Breast cancer surgery can induce postural adaptations that influence spinal alignment. Although previous studies have predominantly addressed coronal deformities such as scoliosis, changes in sagittal alignment, particularly thoracic kyphosis, remain poorly characterized. An increased kyphotic angle has been associated with impaired physical function, emphasizing the importance of assessing sagittal spinal changes after surgery. Although thoracic kyphosis is traditionally measured on standing radiographs, it can also be evaluated using supine chest computed tomography (CT), routinely obtained during postoperative follow-up. This study investigated the impact of breast cancer surgery on thoracic kyphotic angle and assessed the correlation between kyphotic angles measured on supine CT and standing X-rays. Methods: This retrospective study included 185 breast cancer patients who underwent multiple chest CT and whole-spine X-rays. The thoracic kyphotic angle was defined as the Cobb angle from T4 to T12 on sagittal images. Changes in kyphotic angle among the three surgical groups were analyzed using linear mixed-effects models adjusted for age, chemotherapy, radiotherapy, and endocrine treatment. The correlation between supine CT and standing X-ray was analyzed using Pearson's coefficient. Results: The mean follow-up interval was 42.6 ± 6.3 months. The mean angular change was minimal (0.6 ± 2.8°), and no significant effects of time, surgical group, or their interaction were observed. Kyphotic angles measured on standing X-rays strongly correlated with those obtained from supine CT (r = 0.799, p < 0.001), with standing values approximately 7.4° higher. Conclusions: Breast cancer surgery did not significantly alter the thoracic kyphotic angle. Supine CT provides a reliable and practical alternative for the assessment of postoperative kyphosis during follow-up.

The assembly of viral capsids emerges from local interactions between protein building blocks that collectively generate highly ordered shells with defined geometry and robust mechanical properties. However, a quantitative link between atomistic interactions and the macroscopic elastic parameters that determine capsid shape and rigidity has remained elusive. Here, we present an atomistic framework that bridges molecular interactions and continuum-scale mechanics in human papillomavirus type 16 (HPV-16). Using all-atom molecular dynamics simulations with umbrella sampling, we evaluate the potential of mean force governing angular deviations between neighboring L1 pentamers and extract both the preferred interaction angle and the associated bending modulus. We find a clear decoupling between spontaneous curvature of the capsid and bending rigidity. While the optimal interaction angle remains almost invariant across changes in pH and ionic strength, the bending modulus, which is an order of magnitude larger than any previous estimates, is strongly modulated by the electrostatic environment: protonation enhances angular stiffness at low ionic strength, whereas electrostatic screening suppresses this effect at higher salt concentrations. Our results identify inter-capsomer rigidity as a key determinant of capsid size and shape and provide a quantitative framework for linking specific protein-protein interactions to the emergent mechanical properties of self-assembled viral capsids.

We have used variational states to analyze the effects of band geometry on the two-dimensional Wigner crystal with one and two electrons per unit cell. At sufficiently low electron densities, we find that increasing Berry curvature drives a transition into a crystalline state composed of spin-triplet pairs carrying relative orbital angular momentum m=-1. The essential features of this transition are captured by an effective two-electron quantum dot problem in the presence of Berry curvature. Our results point to a purely electronic, strong-coupling mechanism for local spin-triplet pairing in correlated two-dimensional electron systems with quantum geometry.

Load capacity and speed are 2 essential dimensions in the practical application of miniature robots. In recent years, numerous miniature robots with large load capacity or high speed have been developed. However, it is still a challenge to achieve high speed under large load. Inspired by mythological creatures such as dragon, qilin, and chimera that integrate the characteristics of different animals, an insect-scale tripedal piezoelectric robot incorporating multiple biomimetic features is proposed. By emulating the terrestrial flapping of fish tail, a single driving leg with 2 orthogonal bending vibrations is designed to achieve rapid and flexible motion. The tethered robot is 38 mm in length and weighs 8.6 g, exhibiting a maximum forward speed of 313.49 mm/s (8.25 body length per second), a maximum angular speed of 11.54 rad/s, and a minimum curvature radius of 12.64 mm. By emulating the functional roles of the forelimbs and hindlimbs in otariids galloping, a support scheme combining 2 passive wheels with a driving leg is proposed to realize high speed under large load. The forward speed achieves more than 300 mm/s under 200 g (23.26 times self-weight). Moreover, an untethered robot is fabricated. It exhibits a cost of transport of only 1.91 and can operate continuously for 70 min. The untethered robot demonstrates marked potential for operation in narrow spaces, owing to its small size, superior load characteristics, and high flexibility. We believe that this design method of integrating multiple bionic features can offer a new perspective for enhancing the performance of miniature robots.

We study phonon-mediated pairings in a single-flavor metal with a tunable Berry curvature. In the absence of Berry curvature, we discover an unexpected possibility: p-wave superconductivity emerging purely from the retardation effect, while the static Bardeen-Cooper-Schrieffer (BCS) approximation fails to predict its existence. The gap function exhibits sign-change behavior in frequency (owing to the dynamical structure of the phonon-mediated interaction in the p-wave channel), and T_{c} obeys a BCS-like scaling. We further show that the Berry curvature stabilizes the chiral p-wave superconductivity and can induce transitions to higher-angular-momentum pairings. Our results establish that the phonon-mediated mechanism is a viable pairing candidate in single-flavor systems, such as the quarter-metal superconductivity observed in rhombohedral graphene multilayers.

This research article presents a detailed analysis of nonlinear thermal radiation effects in the bioconvective flow of a micropolar nanofluid containing gyrotactic microorganisms over an oscillating curved surface. The formulation accounts for microstructural fluid behavior, Brownian motion, thermophoresis, and microorganism-induced bioconvection, providing a comprehensive framework for understanding transport phenomena in complex fluids. The governing partial differential equations are formulated using a curvilinear coordinate system to accurately capture the influence of surface curvature and oscillation. Nonlinear thermal radiation is incorporated into the energy equation to model realistic radiative heat transfer in high-temperature environments. The coupled system of equations governing momentum, angular momentum, energy, nanoparticle concentration, and microorganism density is reduced to a set of nonlinear ordinary differential equations via similarity transformations. The Homotopy Analysis Method (HAM) is employed to derive analytical solutions, offering adjustable convergence control and high accuracy. Graphical analysis reveals that the microorganism concentration profile decreases with increasing values of the Peclet number, microorganism difference parameter, bioconvection Lewis number, and curvature parameter. Conversely, the local motile density number increases with all the aforementioned parameters. From the tabulated data, it is noticed that the local Nusselt Number magnitude inclines up to 8% with developing values of the dimensionless ratio parameter, while for the Brownian parameter, the y Nusselt number magnitude drops bapproximately 0.05%. The magnitude of the local Motile density number grows up to 1.2% and 5.7% against the microorganism difference parameter and Peclet number, respectively. These findings enhance the understanding of microscale fluid dynamics and have promising applications in bio-microsystems, thermal regulation, and nanotechnology-based fluid processing.

Effects of small-magnitude, long-lasting external electric fields on the mechanical bending response of biological polymers such as microtubule are analyzed. We used coarse-grained Brownian dynamics simulations to model polymers as bead-spring with variable lengths and adjustable bending stiffness that are subject to external forces applied uniformly across the polymer or to the last monomer. Simulations show that, especially when applied over long periods of time, forces as low as 0.001 k B T / σ $$ {k}_BT/\sigma $$ (σ $$ \sigma $$ is the length scale of a monomer) can cause detectable curvature variations in polymers. This small force, equivalent to 3 V / cm $$ 3\kern0.33em \mathrm{V}/\mathrm{cm} $$ for microtubules and 6 V / cm $$ 6\kern0.43em \mathrm{V}/\mathrm{cm} $$ for actin filaments, when applied to microtubules of lengths 400 and 1600 nm and to actin filaments of length 600 nm for the respective durations of 75, 4.8, and 34 μs, produces significant effects on the polymers. Furthermore a force of 0.01 k B T / σ $$ {k}_BT/\sigma $$ ≃ $$ \simeq $$ 6 KV / cm $$ 6\kern0.35em \mathrm{KV}/\mathrm{cm} $$ for a 50-nm-long amyloid fibril requires a pulse duration of 600 μs to produce a significant change. Bending results are also influenced by the directionality of force application; perpendicular forces result in more angular deformation than parallel forces. A critical duration of force exposure required to induce structural changes was defined by the nonlinear dependence of polymer response on force magnitude and stiffness, as revealed by first passage time analysis. These results provide mechanistic insights into the effects of pulsed or variable electric fields on cytoskeletal deformation by quantifying the effective action time of PEFs in biophysical interventions like electroporation and tumor treating fields.

Scalable manufacturing of three-dimensional (3D) micro-/nano-architectures with nanometric precision remains a pivotal challenge in photonics. Here, we introduce a parallel broad-beam ion beam etching (IBE) technique that decouples this fundamental trade-off, enabling the simultaneous and uniform transformation of two-dimensional (2D) patterns into well-defined 3D geometries across entire 4-inch wafers. The IBE platform achieves angular uniformity exceeding 97% and reduces fabrication time by over two orders of magnitude compared to serial focused-ion-beam (FIB) methods. Leveraging this approach, we fabricate two distinct functional devices: a chiral 3D bending metasurface with a giant experimental circular dichroism of 0.8 in the mid-infrared, and a collectively buckled plasmonic grating whose resonance is dynamically tunable over 150 nm in the visible spectrum via curvature control. This technology uniquely combines nanoscale precision with wafer-scale throughput, enabling the construction of 3D metasurfaces via meta-atom assembly and the global modulation of optical responses. Our work establishes a versatile platform that bridges the gap between design complexity and scalable manufacturing for next-generation 3D integrated photonics.