Combinatorial magnetron sputtering was used to generate a library of devices with a wide range of Hf:Zr ratios. The electrical properties of these devices were systematically investigated and correlated to the crystal structure. XRD, XRR, XPS, and EDS were used to measure film structure, thickness, bonding, and chemistry across the sample, respectively. Time-resolved PUND measurements were used to confirm ferroelectric behavior in devices ranging from 49 to 22 atomic % Hf. The switching current and polarization were extracted from the PUND measurements. Ferroelectricity is shown to increase from 49 to 38% Hf. Further decreasing Hf decreases the switching polarization, while also generating peak splitting behavior. Device endurance properties were measured and showed consistent switching up to 104 cycles, while enduring cycling out to 105 cycles. Increased cycling of bimodal switching unified the peak splitting, while increasing the overall switching polarization. XRD structural measurements showed high orthorhombic/tetragonal peaks in the regions exhibiting ferroelectricity, suggesting that the primary phase driving the ferroelectric behavior is orthorhombic.

Abstract Deep learning neural networks provide a powerful approach for segmenting low-contrast cryogenic electron microscopy (cryoEM) images. However, model performance can vary significantly across imaging conditions and may hinder downstream quantitative analyses. Here, we present a structured evaluation workflow to systematically screen segmentation models based on performance, inference speed, robustness across imaging conditions, and reliability of downstream quantitative measurements. Using the Bacterial Cell Envelope Thickness Tool (BCET) as a test case, we evaluate multiple architectures (YOLOv11, YOLO26, U-Net, Detectron2, and SAM3) under low-dose and ultralow-dose cryoEM conditions. While several models achieve high metrics, model choice strongly influences downstream measurements of envelope thickness. Models optimized for high F1-scores may produce unreliable segmentation masks from object crowding, interpolation artifacts or imaging conditions. Our results reveal distinct trade-offs between performance, speed, and robustness amongst models. YOLOv11 provides the highest fidelity membrane segmentation for quantitative measurements and the Meta-based model SAM3 offers improved robustness under ultralow-dose conditions with competitive inference performance. This work provides practical guidance for model selection in cryoEM workflows, emphasizing that optimal choice depends on experimental priorities and downstream analysis requirements rather than metrics alone. These findings are broadly relevant to cryoEM workflows as AI-based analysis expands beyond the biological sciences. Graphical Abstract

Combinatorial magnetron sputtering was used to generate a library of devices with a wide range of Hf:Zr ratios. The electrical properties of these devices were systematically investigated and correlated to the crystal structure. XRD, XRR, XPS, and EDS were used to measure film structure, thickness, bonding, and chemistry across the sample, respectively. Time-resolved PUND measurements were used to confirm ferroelectric behavior in devices ranging from 49 to 22 atomic % Hf. The switching current and polarization were extracted from the PUND measurements. Ferroelectricity is shown to increase from 49 to 38% Hf. Further decreasing Hf decreases the switching polarization, while also generating peak splitting behavior. Device endurance properties were measured and showed consistent switching up to 104 cycles, while enduring cycling out to 105 cycles. Increased cycling of bimodal switching unified the peak splitting, while increasing the overall switching polarization. XRD structural measurements showed high orthorhombic/tetragonal peaks in the regions exhibiting ferroelectricity, suggesting that the primary phase driving the ferroelectric behavior is orthorhombic.

Understanding the life cycle of fungal spores is essential for elucidating their roles in pathogenesis, dispersal, and survival. However, studying spore development under controlled, spatially defined conditions remains challenging. Here, we present the Spore Chamber, a custom-built microfluidic platform engineered for parallel trapping and long-term imaging of individual spores under defined media conditions, enabling real-time visualization of hyphal development. Using Aspergillus fumigatus as a model organism, we demonstrate that sparse trapping of individual spores within size-matched trap geometries enables long-term time-lapse imaging of key developmental stages, including germination, polarized hyphal elongation, branching, and conidiophore formation. To assess the device's capacity to resolve morphogenetic responses to exogenous signals, we introduced lipochitooligosaccharides (LCOs) and short-chain chitooligosaccharides (COs). Rhizobium-derived, non-sulfated LCO (nsLCO) mixtures induced enhanced secondary branching (hyperbranching), a response not previously reported in A. fumigatus under these signal conditions, to our knowledge, whereas sulfated LCOs and CO4 did not significantly alter branching patterns. In addition, long-term confinement and imaging revealed rare developmental morphologies previously described primarily in mutant strains, including split conidiophore formation, elongated phialides, and stress-associated phenomena such as microcyclic conidiation, and chlamydospore development. Together, these results establish the Spore Chamber as a targeted microfluidic platform for single-spore phenotyping and long-term developmental analysis, with applications in fungal biology, chemical signaling studies, and host-microbe interaction research.

In this work, we demonstrated direct-write editing of niobium superconducting thin film devices by focused electron beam induced etching (FEBIE) with the XeF2 precursor. Niobium films of 200 and 50 nm thickness were deposited onto SiO2 coated silicon wafers by magnetron sputtering and fabricated into four-point probe patterns. Directly written FEBIE current crowding Dayem bridge devices were synthesized and characterized. Furthermore, Josephson junctions were fabricated via FEBIE line etches to form a trench across the ≈3.8 µm superconducting channel width. Detailed superconducting transport properties of the devices were characterized.

Understanding how spin texture formation can be engineered is essential for the design and development of spin-based memory and computing devices. Arrays of interacting nanomagnets called artificial spin ices (ASIs) offer a route towards understanding how dipolar interactions can influence the formation of different spin texture states. Using micromagnetic simulations, we studied La0.7Sr0.3MnO3-based brickwork ASIs and showed that the formation of single and double vortices, which we collectively term as complex spin textures (CSTs), depends on the magnetization of the nearest-neighboring nanoislands. Micromagnetic simulations of isolated nanoislands reveal that the tips of CST-bearing nanoislands behave as effective dipoles, thus allowing interactions between CSTs and single domains to be interpreted within an Ising dipolar interaction framework. Through an energy analysis of interacting nanoisland sets, we find that the magnetic configuration of nearest-neighboring nanoislands can induce energy splitting between the two chiralities of a single- or double-vortex state. Moreover, we find that this energy splitting can be predicted by comparing the number of attracting dipolar interactions each chiral state produces. These results can allow us to predict the appearance of a CST in an ASI, which can be leveraged towards developing new ASI systems capable of exploiting CST and Ising states.

Abstract Current segmentation models are capable of routine identification of biological features in noisy cryogenic electron microscopy (cryoEM) images. However, there are still challenges with complete segmentation of high boundary, thin objects such as bacterial cell envelopes and flagella. Moreover, ultralow-dose cryoEM images pose as an additional challenge to boundary distinctions between the object and background. Here, we present TileBac, a benchmark dataset of ultralow-dose montage tiles of Pantoea sp. YR343 to segment bacterial inner and outer membranes for evaluation of model effectiveness. We show that foundation models outperform convolutional neural networks at continuous bacterial cell envelope segmentation despite having lower performance metrics. We release the TileBac benchmark dataset on Hugging Face for further insights into model architecture development.

Reducing protein adhesion is a critical strategy in fouling-resistant material innovation, with broad applications spanning biomedical and healthcare devices, biosensors, industrial and environmental systems, and other important technological domains. In this study, we elucidated protein adhesion behavior on polystyrene-based thin films by neutron reflectometry (NR) and quartz crystal microbalance with dissipation (QCM-D), using both lysozyme and bovine serum albumin (BSA) as model proteins. To this end, semifluorinated polystyrene thin films with gradient wettability and surface energy were fabricated through dry processing using plasma oxidation and gas-phase deposition. Although it is believed that a fully fluorinated alkyl chain offers extremely low surface energy, thus rejecting foulants, and has been used in many fouling-resistant surface designs, enhanced protein-surface interactions were observed consistently in NR and QCM-D results, due to the combined effects of surface morphology and chemistry. On the contrary, depositing shorter fluorinated silane onto a hydrophilic PS surface contributed to a more homogeneous nanoscale fluorine coating, resulting in less initial protein adsorption and improved surface recovery. Comparative analysis of proteins with different sizes on the nanopatterned semifluorinated surface revealed the influence of molecular characteristics on surface interactions. Lysozyme, being smaller and more compact, showed faster adsorption kinetics and higher surface coverage but largely reversible binding, whereas BSA, with its larger and more flexible structure, formed broader and more stable interfacial layers. This study fills the gap in understanding protein adhesion within the range of hydrophobicity (water contact angle ∼90°), as current strategies often associate with extreme hydrophilic and superhydrophobic surfaces due to hydration or low-surface-energy rejection mechanisms, respectively. It also provides in-depth insights into current combinatorial fouling-resistant surface design.

Protein repellent (i.e., antifouling) properties of ultrathin polymeric films have been ascribed to the formation of a dense layer of adsorbed polymers, which causes steric hindrance to protein adsorption on underlying substrates. The antifouling properties of the films are hypothesized to be independent of polymer hydrophilicity based on previous studies involving uncharged polymers. To test the hypothesis and extend it to the realm of charged polymers, we have developed a grafting method for creating ultrathin layers of polyzwitterions on solid surfaces. To demonstrate the efficacy of this method, poly[1-(3-sulfopropyl-1)-2-vinylpyridinium betaine] (P2VPPS) was synthesized via free-radical polymerization and immobilized onto surfaces by using a photoreactive benzophenone derivative as the cross-linker, which was covalently bonded to either quartz or Si/SiOx substrates through a silane anchor. We found that ultrathin films with thicknesses of less than 10 nm can be obtained in dry states using 365 nm ultraviolet (UV) cured/cross-linked surface coatings. These films were found to be hydrophilic and undergo structural rearrangements in the presence of water. The antifouling performance of the films was evaluated using Pseudomonas aeruginosa strain PAO1 bacterium as the fouling agent and exhibited antifouling properties with a kinetic control via the coating method (i.e., spin-coating and drop-casting). In particular, the surface area coverages due to the PAO1 cell attachment on the quartz substrates coated with P2VPPS were found to be ∼5% and ∼0% for the spin-coated and drop-casted films, respectively, after 4 h. These results show that the grafting method can be used to generate surfaces with antifouling properties based on ultrathin films of polyzwitterions.

Antifouling polymer brushes are well-known for their exceptional resistance to unwanted protein adsorption. While experimental studies have extensively characterized protein-polymer brush interactions, computational investigations remain limited, largely due to the challenges in accurately modeling and integrating these complex, multicomponent systems without resorting to oversimplification. To address this challenge, this study presents one of the most comprehensive and realistic model systems to date, comprising the substrate, grafted polymers, and proteins. Our work interprets the interactions between polymer brush and protein based on realistic modeling without simplification. In particular, this study utilizes molecular modeling and simulation of polycationic and polyzwitterionic brushes─poly(dimethylaminoethyl methacrylate) (PDMAEMA), poly(2-(N-oxide-N,N-dimethylamino)ethyl methacrylate) (PNOMA), and poly(2-(N-3-sulfopropyl-N,N-dimethylammonium)ethyl methacrylate) (PSBMA)─grafted onto α-quartz substrates via polymerization initiator linkers. The brush models were developed to closely replicate experimentally synthesized samples and to provide detailed insights into structural and dynamical changes at the molecular level during protein adsorption. Using steered molecular dynamics simulations, we show that the PSBMA brush, due to its high local density, exhibits the greatest resistance to protein insertion. Cα root-mean-square deviation and interaction pattern analyses further reveal that the PSBMA brush also induces the most significant destabilization of lysozyme, while the PDMAEMA brush enhances protein stability through ion-mediated interactions. The PNOMA brush, while requiring the lowest force for protein adsorption, induces greater protein destabilization than the PDMAEMA brush, primarily due to electrostatic repulsion caused by a short carbon spacer length. Hydration analysis reveals that both the PSBMA brush and the lysozyme interacting with it exhibit the most rapid dehydration, attributed to the brush's high local chain density, which results in the greatest lysozyme destabilization and the highest adsorption force. These findings highlight the dual role of antifouling polymer brushes: resisting protein adsorption and modulating protein structural dynamics. This study provides valuable insights for the rational design of next-generation antifouling materials and offers a framework for realistic model development in complex multicomponent systems.

Stimuli-responsive hydrogels that provide controlled degradation can be used as bacteria delivery systems for advanced therapeutic applications. Here, we report the first use of photodegradable hydrogels as materials that can direct bacterial movement, tune mean bacteria speed, and control bacteria delivery through spatiotemporal control of degradation. Hydrogels were formed using base-catalyzed Michael addition reactions between photodegradable poly(ethylene glycol) (PEG) o-nitrobenzyl diacrylate macromers and PEG tetra-thiol cross-linkers within microfluidic channels. Nutrient gradients were generated across the channel, and micron-scale regions of the hydrogel were partially degraded by exposure to controlled doses (2.1-168 mJ/mm2) of patterned 365 nm light. Hydrogel degradation was then characterized in situ using fluorescence visualization of fluorescein-labeled hydrogels. Following characterization, Bacillus subtilis expressing green fluorescent protein was introduced into the device, and its movement up the nutrient gradient was monitored using time-lapse fluorescence microscopy to enable a systematic study of bacteria chemotaxis through the hydrogels at varied levels of degradation. B. subtilis showed minimal adhesion to partially degraded PEG hydrogels, and bacteria mean speed and mean directional change were tunable according to the level of hydrogel photodegradation, with a 2.6-fold difference in mean cell speed measured across the partially degraded hydrogel regions. Finally, the ability to alter bacteria speed and directionality through tunable degradation and without significant adhesion was used to achieve controlled release profiles of bacteria to delivery sites. These findings advance the use of PEG-based hydrogel materials as delivery vehicles for bacterial therapeutic applications and other living material applications that require controlled bacteria transport.

Manipulating polymer interfaces is crucial for understanding how structure influences function in applications spanning biofouling prevention to energy storage. Moreover, observing how polymers adapt their microscopic structure to changes in their local environment can reveal essential properties that govern their performance in such applications, providing key insights into how to design more effective interfaces. Here, a series of "grafting-from" polymer brushes with side chains varying in charge are probed by sum frequency generation (SFG) and modeled using all-atom molecular dynamics (MD) simulations to elucidate how chemical makeup and charge mediate interfacial restructuring in dry versus hydrated states. Results show that charge, in progressing from nonpolar to cationic to zwitterionic, results in dramatic changes in the interfacial structure and overall hydration. While net neutral systems, regardless of bulk phase polarity, show minimal interfacial water structuring, the cationic species exhibits strong bulk water signals from the surface potential. Meanwhile, the polymer brushes themselves restructure in water differently independent of charge, impacting the functional groups that are presented to the aqueous phase. Nonpolar and cationic species, for instance, undergo a change in alkyl group orientations to accommodate hydrating water molecules, whereas the zwitterionic polymer becomes completely disordered in water. Overall, the structure-based behavior trends presented herein have implications in antifouling applications and responsive material interfaces.

Focused electron beam induced etching (FEBIE) with XeF 2 (xenon difluoride) precursor is conducted on multi‐layer exfoliated WS 2 (tungsten disulfide) and monolayer WS 2 grown by chemical vapor deposition (CVD). The films are characterized by atomic force microscopy (AFM) and Raman and photoluminescence (PL) spectroscopy post‐etching. The etch rates/efficiencies are reported as a function of electron beam energy, current, dwell time, and XeF 2 pressure. Bulk film Raman spectra are unchanged post‐FEBIE, indicating minimal subsurface damage. Monolayer WS 2 shows a decrease in Raman and PL intensity post‐FEBIE, with a dose‐to‐clear of ≈2 nC µm −2 . The study reveals regimes affected by the various mass transport contributions such as refresh time and the ratio of electrons/XeF 2 . Spontaneous etching was discovered during FEBIE of large patterned areas due to the long frame/refresh times. Density functional theory and ab initio molecular dynamics simulations compares desorption of SF x and WF x molecules from pristine WS 2 basal planes and pore edges, revealing the spontaneous etching is consistent with etching of partially etched monolayers during each frame. Single‐line etching width of 21 nm, and patterning flakes into 100 nm wide channels are demonstrated. This work demonstrates the possibility of editing WS 2 flakes into electronic devices of arbitrary dimensions for semiconductor applications.