Alzheimer's disease (AD) is a leading cause of death among the elderly, with no existing treatment. The development of therapies is further hindered by a limited understanding of the molecular pathogenesis and the absence of reliable early-detection biomarkers. Neuroimaging and lipidomic studies reveal structural and biochemical alterations in both gray and white matter in AD patients, including disruptions in membrane organization and neuronal signaling pathways. In the present work, we employed lipidomics-guided modeling of membranes in gray and white matter regions under healthy and diseased (AD) conditions, and used all-atom molecular dynamics (MD) simulations to examine how AD-associated alterations in lipid composition influence the structure, spatial organization, and micro-heterogeneity of neuronal plasma membranes. The data suggest that Alzheimer's disease-associated lipid alterations in gray matter (GM) and white matter (WM) impact membrane thickness and microdomain distribution, highlighting the critical role of lipid composition in maintaining neuronal membrane homeostasis and function. Higher-order cholesterol-ceramide-sphingomyelin-enriched domains are more abundant in the neuronal membranes of the GM region under diseased conditions. Under AD-mimicking conditions, lipidomic analyses demonstrate that neuronal membranes in GM experience more substantial compositional and structural remodeling than those in WM. Our results show significant changes in membrane microdomain distribution across the lipid bilayers, and, interestingly, these changes are more pronounced in the gray matter than in the white matter. This study establishes a framework for modeling the tissue-specific lipidomics data to understand how disease-driven compositional changes affect the structure, organization, and dynamics of biological membranes.
The size dependence of contact angles for small droplets on solid substrates is typically attributed to line tension. While previous studies have shown that the apparent line tension on rigid substrates is wettability-dependent, the influence of substrate stiffness on line tension for soft, deformable substrates remains elusive. Here, we experimentally demonstrate that the apparent line tension on soft substrates exhibits a clear dependence on substrate stiffness. Using atomic force microscopy to image ionic liquid nanodroplets on polydimethylsiloxane substrates with varying cross-linking densities, we find that the contact angles depend on both the droplet contact radius and the substrate stiffness. Analysis based on the modified Young's equation for soft substrates yields negative apparent line tensions ranging from -5.9 × 10-11 to -3.5 × 10-10 J m-1, in good agreement with theoretical predictions and previous experimental results on rigid substrates. Notably, the absolute value of the apparent line tension decreases on softer substrates, revealing a direct coupling between substrate elasticity and the thermodynamic excess free energy in the three-phase confluence region.
Binary mixtures developed as thresholdless antiferroelectric (TLAF) materials, MC881-MC815 and MC881-MC452, are studied using optical rotatory power (ORP), resonant soft x-ray scattering (RSoXS), and dynamic light scattering (DLS). A single subphase is confirmed to exist in both mixtures by ORP, stably over a wide temperature range (around 80^{∘}C below RT) but in a narrow concentration range (1-3 wt.%), with curved boundaries; between SmC_{A}^{*} and the subphase, the ratio of synclinic and anticlinic orderings changes continuously. The antiferroelectric four-layer superlattice structure of the subphase is now firmly established by RSoXS using free-standing films, although a two-layer SmC_{A}^{*} structure is observed in silicon nitride membrane cells often used in RSoXS, highlighting the influence of surface conditions. The TLAF properties of the subphase are confirmed in homogeneously aligned cells by observing apparent tilt angles induced by an applied electric field. The relaxation times responsible for the TLAF properties are studied by DLS, indicating the smooth flip-flopping of a group of molecules in a single layer, which must also be responsible for the continuous change among SmC_{A}^{*}, the subphase, and SmC^{*}. Each smectic layer appears to play an important role as a mesoscopic entity.
We report the mechanism underlying two-step yielding in repulsive colloidal microgel glasses under shear deformation. Strain sweep and start-up flow experiments demonstrate the existence of two-step yielding, which was further investigated by creep-recovery, and Lissajous-Bowditch curves to probe intra-cycle nonlinearities. By increasing the microgel volume fraction, we track the transition from entropic to jammed glass regimes and examine the distinct roles of particle softness and crosslinking heterogeneity in yielding behaviour. Soft core-shell particles exhibit two-step yielding in the jammed glass regime at a frequency of ω = 1 rad s-1. We compare the results for three types of particles: soft core-shell; stiff core-shell; and homogeneously crosslinked. We find that stiff core-shell and homogeneous particles do not exhibit two-step yielding under any experimental conditions. These findings demonstrate that softness combined with a core-shell particle structure is necessary to support two-step yielding. Intra-cycle nonlinearities reveal that strain stiffening develops between the first and second yield points, arising from resistance to macroscopic flow at and beyond the first G″ peak. This resistance to cage breaking originates from the strong interlocking of interpenetrated polymer chains that occurs during microgel deformation and compression in the jammed state. Macroscopic flow begins at the second yield point, where particles escape their cages by breaking the interlocking structure, leading to the G'-G″ crossover.
Artificial intelligence is rapidly permeating modern technology, but its growth is increasingly constrained by the costs of delivering power and removing heat. Neural computation offers a striking counterpoint, for it achieves sophisticated information processing at exceptionally low energy by exploiting ionic flows and adaptive conductance. Inspired by the Hodgkin-Huxley view that function emerges from ion-transport dynamics, recent work has begun to implement memory and learning directly in fluids, where ions simultaneously carry signals and encode the internal device state. This Review charts the emerging landscape of fluidic ionic memristors, from soft, bioinspired materials to manufacturable solid-state nanofluidic architectures. In lipid bilayers, droplet networks, tissues and ionic polymers, electrical activity is intrinsically coupled to chemistry and mechanics, enabling plasticity across multiple timescales. In rigid nanopores, nanochannels and angstrom-scale slits, the softness is transferred from the scaffold to the ionic degrees of freedom, where electric double-layer dynamics, concentration polarization and confinement-driven effects produce history-dependent transport in robust inorganic frameworks. Hybrid approaches integrate gels, brushes, particles, or biomolecules within microfabricated structures to combine stability with rich analogue dynamics. We conclude by outlining the key requirements for translation from reproducibility to scalable integration towards ionic intelligence technologies.
Optical tweezers are widely used in single-molecule biophysics, cell biomechanics and soft matter physics, but require a human operator, limiting throughput and repeatability. Here we present a smart optical tweezers platform, named SmartTrap, capable of performing complex experiments autonomously by integrating real-time three-dimensional particle tracking, custom electronics and a microfluidics system. Through a series of experiments, we demonstrate it can operate continuously, acquiring high-precision data over extended periods of time. By bridging the gap between manual experimentation and autonomous operation, SmartTrap establishes a robust and open-source framework for the next generation of optical tweezers research, capable of performing large-scale studies in single-molecule biophysics, cell mechanics and colloidal science with minimal experimental overhead and operator bias.
Circularly polarized light is essential for applications in optical communication, quantum computing, display systems, and chiral material characterization, among others. Yet, the inherently weak chiroptical response of most materials remains a fundamental limitation. Chiral nanophotonics overcomes this challenge by strongly enhancing light-matter interactions through resonant subwavelength nanostructures. Among these, emitters coupled to chiral bound states in the continuum (BICs) have shown excellent performance. However, the majority of chiral BIC architectures depend on costly nanofabrication processes, which significantly limit their scalability. Here, soft nanoimprinting lithography is used to produce chiral nanostructures that enable chiral lasing from an organic dye embedded in the patterned resist. Nearly fully circularly polarized lasing emission (97%) arises from coupling the dye photoluminescence to supported BIC resonances, as revealed by angular dispersion measurements and corroborated by Fourier microscopy and FDTD simulations. These results confirm coupling between orthogonally polarized TE and TM modes causing the BIC. Our work establishes a scalable route toward highly chiral light sources, advancing practical nanophotonic platforms for quantum and optical technologies.
Soft electroactive polymer materials are of great interest for soft robotics and biomedical applications because of their large deformability and fast response. Plasticized poly(vinyl chloride) (PVC) gels, particularly PVC/dibutyl adipate (PVC/DBA) gels, exhibit significant bending deformation under relatively low electric fields. In this study, we enhanced the electromechanical response of PVC/DBA gels by adding salts with controlled ion sizes, including ionic liquids and lithium salts. Rheological measurements revealed a critical gelation concentration (PVC weight fraction) of w = 0.013 and a fractal dimension of 1.88. At a fixed PVC concentration (w = 0.143) corresponding to a post-gel state, salt addition (5.4 × 10-6 mol g-1) increased electrical conductivity by approximately fivefold without significantly affecting elasticity. All gels showed anode-directed bending under an DC electric field, with deformation magnitudes more than five times larger than those of salt-free gels. The most pronounced bending was observed for gels containing a small anion, bis(fluor sulfonyl)imide, and a large cation, 1-ethyl-3-methylimidazolium, which is attributed to asymmetric effective charge densities formed in the electric double layer at the electrodes. These results demonstrate that the ion size control of added salts is an effective strategy for enhancing the electromechanical performance of PVC/DBA gels under low electric fields.
Hydrogel-based flexible sensors are attractive for wearable electronics because of their softness, conformability, and tissue-like mechanics. Nevertheless, integrating high toughness, robust adhesion, self-healing ability, anti-freezing capability, and reliable strain sensitivity into a single hydrogel remains challenging. Here, we report a multifunctional conductive hydrogel in which ionic liquid-functionalized microspheres (MS) are introduced into an oxidized xanthan gum/chitosan (OXG/CS) matrix to serve as reinforcing nodes, dynamic physical crosslinking sites, and sacrificial energy-dissipation units. The microspheres interact strongly with the surrounding polymer chains through hydrogen bonding and electrostatic interactions, while the OXG/CS network provides reversible imine bonds. This hybrid dynamic network markedly improves the mechanical performance of the hydrogel, yielding an elongation at break of more than 970%, a toughness of 320 kJ m-3, and strong interfacial adhesion, while retaining excellent self-healing behavior. The incorporation of ionic species also endows the hydrogel with high conductivity (4.1 S m-1) and excellent anti-freezing performance. As a strain sensor, the hydrogel exhibits high sensitivity, with a gauge factor of 6.70 in the 100-600% strain range and can reliably detect subtle physiological signals such as pulse waves and vocal-cord vibrations. These results demonstrate that ionic microsphere reinforcement is an effective strategy for constructing multifunctional hydrogel sensors for use in complex environments.
Active adaptive matter has attracted considerable interest due to its rich, largely unexplained dynamics and its relevance to a wide range of synthetic and biological materials. An important subclass of such systems consists of active particles that can remodel the network in which they move. Here, we introduce a minimal yet versatile model of active particles moving on an adjustable network. In this model, particles undergo discrete run-and-tumble motion along the links of a triangular lattice and leave behind a trail of temporarily blocked links. These closed links cannot be traversed by other particles and reopen only after a characteristic healing time. The resulting trail-mediated blocking mechanism is fundamentally distinct from more familiar interactions such as excluded-volume effects. In the high-persistence limit, we find a qualitative contrast between the two mechanisms: while steric blocking leads to reduced diffusivity with increasing persistence, trail-induced blocking causes diffusivity to increase monotonically. We characterize this fundamental difference and the unexpected transport properties that arise when both blocking mechanisms are present, and discuss potential applications.
Ionogels are promising for flexible electronics, but their use in triboelectric nanogenerators (TENGs) has been limited by weak mechanical performance and poor interfacial control. Here, we report a molecularly engineered ionogel (VP-IL) with a "rigid-flexible combined skeleton," featuring bicontinuous phase separation via multiple supramolecular interactions. Created by copolymerizing rigid 1-vinylimidazole (1-VIM) and flexible 2-phenoxyethyl acrylate (PhEA) with ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide([EMIM][TFSI]) as dynamic crosslinker and phase-separation driver, the VP-IL ionogel exhibits a well-defined bicontinuous phase separation orchestrated through strong cation-π anchoring of [EMIM]+ onto PhEA benzene rings. The synergistic interplay of this interaction with hydrogen bonds and π-π stacking results in efficient energy dissipation and strain-hardening in VP-IL. Solid-state NMR reveals the slow segmental motion activated by ionic liquids, thereby endowing the material with strong mechanical properties and charge transport capabilities. This dynamic network allows modulus switching over three orders of magnitude and rapid shape memory, supporting UV-curable 3D printing. An intelligent TENG with a reconfigurable friction interface was developed by this material, whose output charge can be regulated on demand through micro-patterning. This work offers a new material platform for the design of a new generation of adaptive soft robots and wearable self-powered systems.
Approaches in tissue engineering, organoid culture, and organs-on-chip have propelled the development of increasingly sophisticated in vitro models of human tissues. However, as they are formed from natural cells, it is challenging to control their molecular composition and biophysical properties, increasing variability and limiting their robustness. To overcome these limitations, we introduce a self-assembly strategy for synthetic cells that enables the formation of millimeter-sized synthetic constructs based on single synthetic cells. Specifically, we functionalize the lipid membrane of synthetic cells with cholesterol-tagged single-stranded DNA aptamers, which drive programmable intercellular adhesion through sequence-specific hybridization. This allows individual synthetic cells to interconnect into higher order 3D constructs. By varying aptamer complementarity, internal architecture with spatially distinct functional zones and tuneable mechanical properties can be encoded. Most importantly, the DNA-driven self-assembly operates directly in cell culture medium, is compatible with high-throughput microwell formats enabling scalable screening workflows and is reversible by DNA displacement. To demonstrate the biological functionality of these synthetic tissues, we incorporate T cell-stimulatory antibodies into spatially segregated tissue regions. This design mimics lymph node organization and supports infiltration of natural primary human T cells, which subsequently expand within the synthetic tissue. Together, these results establish a route to tissue-scale matrices built from synthetic cell collectives and represent a critical step toward functionally integrating living and non-living matter.
Alzheimer's disease (AD) is a complex neurodegenerative disorder mediated by multiple pathological factors, including amyloid-β (Aβ) plaque deposition and oxidative stress. Herein, we report a new class of sequentially activated dual-lock-responsive fluorescent probes, D-BDY and T-BDY, which were designed by integrating pyrrole-based electron-donating units and molecular rotors into the BODIPY scaffold. This strategic design enabled photoinduced electron transfer (PET) and twisted intermolecular charge transfer (TICT) modulated fluorescence responses to both Aβ1-42 aggregates and hypochlorite (ClO-). The probes exhibited remarkable fluorescence enhancement (50-100-fold) when exposed to a mixed solution containing both ClO- and Aβ1-42 aggregates. Confocal imaging and staining of Aβ-containing brain slices revealed that the probes preferentially bind to the dense β-sheet-rich cores of plaques, and their colocalization with thioflavin-T (ThT) was further enhanced following ClO- activation. Furthermore, in vivo imaging in an APP/PS1 transgenic AD mouse model demonstrated that D-BDY successfully crossed the blood-brain barrier (BBB), enabling real-time monitoring of Aβ1-42 plaques and the oxidative microenvironment. The observed fluorescence intensity exhibited a strong correlation with pathological severity and was significantly attenuated upon antioxidant treatment. These results established D-BDY as a promising single-molecule dual-locked fluorescent probe capable of sensitively visualizing Aβ1-42 aggregation and ClO--related oxidative stress in vivo, offering a valuable tool for AD diagnosis and pathological progression monitoring.
Chiral active Brownian particles (CABPs) are self-propelled agents with intrinsic rotational dynamics, giving rise to circular trajectories commonly observed in biological and synthetic microswimmers. Understanding how CABPs explore confined environments and locate targets is crucial for characterizing transport, search efficiency, and reaction processes in physical and biological systems. We study the escape dynamics of CABPs from one- and two-dimensional confined domains. In one dimension, we consider intervals with either two absorbing boundaries or a reflecting boundary on one side and an absorbing boundary on the other, and derive closed-form asymptotic solutions in the high-chirality regime, revealing the quantitative scaling of the mean first passage time (MFPT) as a function of particle rotation speed (chirality). In two dimensions, we analyze escape from a disk containing one absorbing arc or two symmetric absorbing arcs. By numerically solving the governing partial differential equations, we compute the MFPT for CABPs to escape the domains as a function of the particle's initial orientation, self-propulsion speed, angular velocity, and domain geometry. Our results show that, depending on the parameters and geometry, the MFPT can exhibit non-monotonic behavior as a function of chirality. A minimal escape time exists at an intermediate value of chirality, where the rotational time scale balances the active swimming time scale, redirecting a particle towards the exit which would otherwise be blocked due to unfavorable initial orientation. Our work offers a comprehensive characterization of CABP escape dynamics in canonical confinements and identifies chirality as a key control parameter for transport and search in confined physical and biological systems.
The physical properties of van der Waals materials are highly dependent on their stacking sequences. However, constructing layered materials with specific compositions and desired stackings is challenging. Here we show that a solvent-directed strategy enables targeted stacking in van der Waals metal-organic frameworks, an emerging class of van der Waals materials. By leveraging the tunable metastable states of conjugated ligands through various solvents, and stabilizing these states via metal-ligand coordination, we enable the inheritance of stacking patterns from ligands to van der Waals metal-organic frameworks. Notably, this strategy enables the controlled manipulation of stacking sequences and divergent charge transport regimes in two-dimensional and three-dimensional van der Waals metal-organic framework single crystals, yielding an electrical conductivity of 1,792 S cm-1. These results provide a versatile approach for designing layered materials with programmable stackings and tailored electronic properties.
Amphiphilic block copolymers, such as pluronic triblock copolymers, are widely employed to engineer stimuli-responsive hydrogels for applications ranging from biomedicine to energy and food industries. In this study, we investigated how the self-assembly temperature of pluronic P123, P104, and F127 affects the crosslinking behavior and the temperature-dependent volume changes of the resulting hydrogels. Each pluronic bearing hydroxyl end-group was functionalized with methacrylic moieties to enable chemical photo-crosslinking and hydrogel formation. Before crosslinking, the impact of chain-end functionalization on micellar organization was evaluated using rheological measurements to map changes in the phase diagrams of the micellar solutions. The results revealed significant shifts in micellar organization for all three pluronics following methacrylation of the hydroxyl groups. Photorheological experiments further demonstrated that the micellar organization directly influenced the kinetics of chemical crosslinking: organized micellar states facilitated faster and more efficient photocrosslinking reactions. Temperature sweeps on the crosslinked systems showed that F127-MA, P123-MA, and P104-MA hydrogels exhibited significantly reduced thermoresponsiveness when crosslinked in an organized state. Finally, the rheologically observed thermal behavior was correlated with the hydrogels' swelling properties. The thermal responses of the pluronic hydrogels resulted in up to 30% water release when crosslinked in an isotropic state, compared to 20% when crosslinked in an organized state. These findings highlight the critical role of micellar organization in tuning the physicochemical properties of pluronic-based hydrogels.
Aqueous protein-stabilized foams are omnipresent in daily life, e.g., within food or in industrial applications. In this study, we apply a multiscale approach and investigate proteins adsorbed at the air/water interface, as well as foam films and macroscopic foams stabilized by four different proteins: β-lactoglobulin (BLG), bovine serum albumin (BSA), casein (CN), and lupine protein isolate (LPI). Protein adsorption at the air/water interface was investigated using Brewster angle microscopy (BAM) and X-ray reflectivity (XRR). Adding to individual thin film studies with a thin film pressure balance (TFPB), we employed small-angle scattering (SANS), which is able to investigate Newton black films (NBFs) within macroscopic foams. The film is thinnest near the isoelectric point (IEP), while adsorption layers at the air/water interface are thickest at the IEP. Importantly, we report for the first time the properties of NBFs within protein foams, enabling a direct comparison across length scales with individual foam films.
Based on spatially-temporally resolved polarized optical microscopy (str-POM) measurements, we studied the fracture behavior of ductile and brittle glassy polymers as well as highly crosslinked rubbers to draw the following conclusions: (1) there is no tip plasticity below a threshold load in ductile plastics such as polyethylene terephthalate. (2) In ductile polymer glasses, before tip yielding at a common tip stress, the remote load scales with notch length a as a-1/2, in agreement with the Inglis solution. (3) A finite stress saturation zone is observed in elastomers at loading levels even well below fatigue threshold due to significant crack tip blunting. (4) When the thickness is small enough for the plane stress condition to prevail at crack tip, in double-edge notch tension (DENT) for both ductile glassy polymers and rubbers that is characterized by ligament length l, nominal strain in the ligament is defined by εlig = X/l, where X is tensile displacement; tensile force F increases linearly with X independent of l; tip stress increases linearly with the far-field σlig (∼εlig). By demonstrating stress concentration at the crack tip in DENT in elastic materials and characterizing crack propagation in ductile polymers, the present study fills the missing gap in our understanding of fracture behavior in a wider range of polymeric materials. The acquired knowledge may be useful to guide specific design for packaging materials.
We investigate the encapsulation of water by a thin elastic film as a minimal model of elastocapillary self-folding with fluid transport. An equilateral triangular polydimethylsiloxane film is lifted quasi-statically from a water surface, while its side length and thickness are systematically varied. Depending on these parameters, the film exhibits three distinct morphologies: folding, recoiling, and liquid encapsulation. We show that the morphology is governed by the interplay of surface, gravitational, and bending energies, and that encapsulation occurs only within a narrow parameter region where the elastocapillary, elastogravity, and capillary length scales become comparable. This provides a simple physical criterion for liquid encapsulation by elastic films.
Past investigations into droplet impact dynamics have mostly used either relatively smooth substrates or air-trapping superhydrophobic textures. For this reason, existing models for predicting the maximum spreading ratio of impacting droplets (βmax = Dmax/D0) are unable to capture the influence of surface roughness. In this study, we investigate the influence of roughness and substrate wettability on the dynamics of water impacting at Weber numbers where splashing is minimal, with a specific focus on the maximal spreading diameter of Wenzel droplets. The surface mean roughness amplitude, Ra, was varied widely by laser etching substrates comprised of either glass (Ra = 0.012-22.49 µm), PETG (Ra = 1.18-55.04 µm), or aluminum (Ra = 2.21-58.31 µm). The surface wettability ranged from strongly hydrophilic to weakly hydrophobic and depended on the choice of substrate material, the extent of surface roughness, and the roughness-dependent modification of the intrinsic wettability due to the laser or hydrocarbon adsorption. We develop a new energy model for predicting βmax for both elastic (We < 30) and inelastic (We ≥ 30) droplet impact regimes, where surface energy and viscous dissipation terms are modified to incorporate surface roughness effects. We show that the universality of existing (roughness-independent) models for βmax becomes incomplete for roughness ratios of r ≳ 2, whereas our roughness-dependent model has excellent agreement across all r values. By explicitly incorporating surface roughness into the energy balance, we extend the predictive capability of droplet spreading models to achieve an extended predictive framework for water-droplet spreading on rough substrates.