Μm Scale Research Articles

Insights into the composition and assembly mechanism of microbial communities on intertidal microsand grains

IntroductionMarine microorganisms are essential in marine ecosystems and have always been of interest. Currently, most marine microbial communities are studied at the bulk scale (millimeters to centimeters), and the composition, function and underlying assembly mechanism of microbial communities at the microscale (sub-100 micrometers) are unclear.MethodsThe microbial communities on microsand grains (40–100 µm, n = 150) from marine sediment were investigated and compared with those on macrosand grains (400–1000 µm, n = 60) and bulk sediments (n = 5) using amplicon sequencing technology.ResultsThe results revealed a significant difference between microsand grains and macrosand grains. Microsand grains had lower numbers of operational taxonomic units (OTUs(97%)) and predicted functional genes than macrosand grains and bulk-scale samples. Microsand grains also showed greater intersample differences in the community composition and predicted functional genes than macrosand grains, suggesting a high level of heterogeneity of microbial communities at the microscale. Analyses based on ecological models indicated that stochastic processes dominated the assembly of microbial communities on sand grains. Consistently, cooccurrence network analyses showed that most microbial cooccurrence associations on sand grains were highly unstable. Metagenomic sequencing and further genome-scale metabolic modeling revealed that only a small number (1.3%) of microbe pairs showed high cooperative potential.DiscussionThis study explored the microbial community of marine sediments at the sub-100 µm scale, broadening the knowledge of the structure and assembly mechanism of marine microbial communities.

Active Solid-State Nanopores: Self-Driven Flows/Chaos at the Liquid-Gas Nanofluidic Interface.

Here, we present a comprehensive study of self-driven flow dynamics at the liquid-gas interface within nanofluidic pores in the absence of external driving forces. The investigation focuses on the Rayleigh-Taylor instability phenomena that occur in sub-100 nm scale fluidic pores interfacing between 2 μm scale water and air reservoir. We obtain a flow velocity equation, and we validate it using simulations, concentrating on the mass transfer efficiency of these flow structures. Furthermore, we introduce the concept─"active solid-state nanopore"─that exhibits a self-driven flow switching behavior, transitioning between active and passive states without the need for mechanical components. We found a unique state of chaos at the nanoscale resembling the chaotic motion of fluid. This study contributes to the preliminary understanding of fluid dynamics at the classical-quantum interface. Implications of self-driven nanofluidics extend across diverse fields from biosensing and healthcare applications to advancing net-zero sustainable energy production and contributing to the fundamental understanding of fluid dynamics in confined spaces.

Detrital gold morphology and recycling around the early Miocene St Bathans paleovalley, Central Otago, New Zealand

ABSTRACT The St Bathans paleovalley developed as a major southwest-draining fluvial system during early Miocene rejuvenation of the Central Otago landscape. Rounded quartz pebbles and detrital gold were recycled from Eocene quartz pebble conglomerates into the headwaters of this Miocene paleodrainage system on the northern margin of the Otago Schist belt. Gold particle morphology is mostly irregular and rough, locally with relict gold crystal shapes, plus a minor component of well-defined flakes. Incremental rounding and surface deformation at the 10 µm scale has occurred through several recycling events in Central Otago, hindering linkage of Miocene and younger placer gold to ultimate basement sources. More intense deformation of the gold, forming thin flakes, occurred in the lower reaches of the Miocene paleodrainage system as gold was transported >100 km to eastern Southland. Hence, the St Bathans paleovalley has been an important source of gold for historic mining in Central Otago and Southland.

Supershear Rayleigh wave imaging for quantitative assessment of biomechanical properties of brain using air-coupled optical coherence elastography.

Recently, supershear Rayleigh waves (SRWs) have been proposed to characterize the biomechanical properties of soft tissues. The SRWs propagate along the surface of the medium, unlike surface Rayleigh waves, SRWs propagate faster than bulk shear waves. However, their behavior and application in biological tissues is still elusive. In brain tissue elastography, shear waves combined with magnetic resonance elastography or ultrasound elastography are generally used to quantify the shear modulus, but high spatial resolution elasticity assessment in 10 μm scale is still improving. Here, we develop an air-coupled ultrasonic transducer for noncontact excitation of SRWs and Rayleigh waves in brain tissue, use optical coherent elastography (OCE) to detect, and reconstruct the SRW propagation process; in combing with a derived theoretical model of SRWs on a free boundary surface, we quantify the shear modulus of brain tissue with high spatial resolution. We first complete validation experiments using a homogeneous isotropic agar phantom, and the experimental results clearly show the SRW is 1.9649 times faster than the bulk shear waves. Furthermore, the propagation velocity of SRWs in both the frontal and parietal lobe regions of the brain is all 1.87 times faster than the bulk shear wave velocity. Finally, we evaluated the anisotropy in different brain regions, and the medulla oblongata region had the highest anisotropy index. Our study shows that the OCE system using the SRW model is a new potential approach for high-resolution assessment of the biomechanical properties of brain tissue.

Development of novel parameters for characterising scale morphology of wool fibre and its correlation with dye diffusion coefficient of acid dye

This paper reports the development of novel surface parameters which can be used to characterise the scale structure of wool fibres obtained from different breeds. Scanning electron microscopy and subsequent image analysis technique were used to study wool fibres from Leicester, Dartmoor, Ryeland and Herdwick breeds of sheep. Novel scale parameters related to wool fibre’s effective chemical diffusion pathway were developed. Namely, the total scale perimeter per 100 µm fibre length and scale perimeter index, which is the total scale perimeter per 100 µm length divided by the fibre diameter. Wool fibres obtained from different breeds showed significant differences in their scale pattern with the change in fibre diameter. The scale perimeter per 100 µm length increased with the fibre diameter and showed a polynomial correlation. It was also demonstrated that an increase in the diameter of the wool fibre resulted in an increase in the apparent dye diffusion coefficient, which contrasts the established theory that finer fibres are associated with a higher dyeing rate. The increase in effective diffusion pathway (total scale perimeter per 100 µm) for the wool fibres (among different breeds) resulted in a higher dye diffusion rate at the initial phase of dyeing (liquor to surface).

Size-dependent and sex-specific negative effects of micro- and nano-sized polystyrene particles in the terrestrial invertebrate model Drosophila melanogaster

Microplastic pollution is believed to be one of the most widespread and long-lasting changes on a global scale. Our understanding that microplastics significantly impact terrestrial systems and are a global change stressor continues to grow. In the present study, we investigated the negative effect of long-term (28 days of exposure in food) polystyrene particles of micro (1.0–1.9 µm, 0.4–0.6 µm) and nano (0.04–0.06 µm) scale, in low doses, on the fruit fly – representing a common, globally distributed terrestrial invertebrate, and a model species in many fields. Our observations involved such parameters as ingestion and transfer of particles, survival, reproduction, changes in ultrastructure and tissue and cell responses in midgut epithelium (the place of direct contact with plastic), ovary, and testis in adults, and transgenerational effects in larvae. These observations may indicate possible toxic effects of the tested substances, even in low doses, that can be expected in other taxa, in terrestrial ecosystems. We observed a negative impact of polystyrene particles on the fruit fly survival, midgut, ovary, and testis, involving ultrastructural alterations, such as autophagy and/or ultimately necrosis in the midgut, triggering oxidative stress and activating processes of antioxidative protection. Despite the changes, midgut function and reproduction were not altered – spermatogenesis and oogenesis proceeded normally. The effect was size-dependent – the smaller the polystyrene particles were, the more substantial was the impact they caused. Ultrastructural changes and studied parameters, i.e., generation of ROS (overproduction of which generates oxidative stress), total glutathione concentration (involved in defense against ROS, acting in distinct pathways), and total antioxidant concentration (the oxidative defense system) showed the highest levels after exposure to the smallest nanoparticles, and vice versa. The effect was also sex-dependent, with male flies being more sensitive. Negative effects in males were more substantial and more prominent, even after contact with larger particles, compared to females. The smaller particles (0.4–0.6 µm, 0.04–0.06 µm) were transferred to the ovary and accumulated in the oocytes. In this case, a transgenerational negative effect was detected in larvae. It was characterized by size-dependent alterations, with smaller particles triggering higher levels of ROS and cellular oxidative response. Only the largest particles (1.0–1.9 µm) did not pass into the gonad and did not alter the larvae. These observations together demonstrated that polystyrene particles of micro- and nanoscale, even in a low dose, can induce numerous negative effects on terrestrial invertebrates.

Time-dependent wetting behavior of the micro-textured stainless steel 316L using the mechanical indentation method

The current work introduces a mechanical indentation method to develop and characterize the pyramid-shaped micro-texturing in a square array on biomedical grade SS 316L. The surface morphology, topography, and roughness profiles of the pyramid-shaped micro-textured surfaces are characterized using a field emission scanning electron microscopy, three-dimensional (3D) optical profilometer, and atomic force microscopic (AFM) analysis. The field emission scanning electron microscopy results showed that micro-textures are formed in a periodic manner at different center distances within 2% of error. The AFM 3D image shows the bulging effect near the corners of the pyramid textures due to the application of applied load. Further, the Sa values of the textured samples are found as 1.223, 0.52, and 0.271 µm for the center distance of 150, 250, and 350 µm, respectively, and come under the micro-roughness (Sa > 1–10 µm) and nano-roughness (Sa < 1 µm) scale range. Further, the surface functionality was analyzed in terms of Young's contact angle. The textured surface presents hydrophilic wetting behavior with a contact angle of 42.8°, compared to the untextured part (97.4°) for deionized water. Moreover, with PBS, the textured sample show presents a minimum contact angle, that is, 22.7°, compared to the untextured part (81.1°), which presents a high affinity for simulated body fluid. The results indicate that an increase in surface roughness makes the hydrophilic surface more hydrophilic, supporting the Wenzel statement. Therefore, the mechanical indentation technique can be a promising method for fabricating micro-textured surfaces for implant materials.

Design criteria for selective nanofluidic ion-exchange membranes

Polymeric ion-exchange membranes (IEMs) are key to many electrochemical processes, but their intrinsic selectivity limitations restrict scale-up possibilities. Nanofluidic IEMs, based on inorganic rigid materials and charged nanopores, offer a promising alternative. We present design criteria for selective nanofluidic membranes. We used commercial anodized aluminium oxide (AAO) membranes with varying pore sizes to measure permselectivity between different KCl concentrations. Our experiments reveal that membranes with 10-nm pores have permselectivities above 90%, comparable to those of polymeric IEMs, up to electrolyte concentrations of 0.15 vs. 0.75 M. To our knowledge, this is the highest reported ion selectivity for nanofluidic IEMs. Conversely, asymmetric AAO membranes featuring a thin selective layer, exhibited low permselectivity. We explored the influence of other parameters through simulations using the space-charge model. Our numerical results indicate that pore size and surface potential are the most sensitive parameters for increasing selectivity. Additionally, pore length has a minimum requirement for good performance although increasing it beyond the μm scale yields no significant result. This study highlights nanofluidic IEMs as a promising alternative to polymeric IEMs and their capability to improve performance of many electrochemical processes, especially those involving low electrolyte concentrations on at least one membrane side.

Atomically smooth films of CsSb: A chemically robust visible light photocathode

Alkali antimonide semiconductor photocathodes provide a promising platform for the generation of high-brightness electron beams, which are necessary for the development of cutting-edge probes, including x-ray free electron lasers and ultrafast electron diffraction. Nonetheless, to harness the intrinsic brightness limits in these compounds, extrinsic degrading factors, including surface roughness and contamination, must be overcome. By exploring the growth of CsxSb thin films monitored by in situ electron diffraction, the conditions to reproducibly synthesize atomically smooth films of CsSb on 3C–SiC (100) and graphene-coated TiO2 (110) substrates are identified, and detailed structural, morphological, and electronic characterization is presented. These films combine high quantum efficiency in the visible (up to 1.2% at 400 nm), an easily accessible photoemission threshold of 566 nm, low surface roughness (down to 600 pm on a 1 μm scale), and a robustness against oxidation up to 15 times greater than Cs3Sb. These properties lead us to suggest that CsSb has the potential to operate as an alternative to Cs3Sb in electron source applications where the demands of the vacuum environment might otherwise preclude the use of traditional alkali antimonides.

Synthesis, Characterizations of HDTDHP Macro-Crystals by Experimental-Electrical, Electronic and Computational Structural Proviso for Opto-Electronic and Photonic Utilities

The 7-hydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene-HDTDHP crystal is well-grown within a period of 22 days and is a monoclinic type of system of crystals with space group P21/n. The CHNSO methodology shows the formation of the entitled compound; the HDTDHP is RISE effect type of crystals with the Vicker’s proviso. The surface morphology of HDTDHP crystal is analyzed for macro scale as 200 μm scaling respectively as per SEM study. The higher amount of the dielectric constant at lower frequencies is by the existence of all polarizations; also, the dielectric loss is getting decreased with increase in temperature. The electronic filter use is 3.9987 microns for macro-influx as opto-electronic, extensive NLO type uses; as observed from UV-Visible spectrum from the cut-off and wavelength range of HDTDHP with % transmittance. The frequency doubling and tripling of the macro sample is analyzed in continuation of the Z scan and SHG of the NLO class and confirms the proper electronic functionalities. The HDTDHP crystalline sample is mainly used as photonic-macro level tool, in filters as macro-influx portrayal, in NLO utility as opto-electronic tool by the transmittance data as well as by Z scan and in frequency enhancers and projective use in displays.

Distinctive Features and Fabrication Routes of Metallic-Glass Systems Designed for Different Engineering Applications: A Review

Materials with a disordered atomic structure, often termed glassy materials, are the focus of extensive research due to the possibility of achieving remarkable mechanical, electrochemical, and magnetic properties compared to crystalline materials. The glassy materials are observed to have an improved elastic modulus combined with a higher strength and hardness. Moreover, better corrosion resistance in different mediums is also observed for glassy solids, which is difficult to attain using conventional crystalline materials. As a result, the potential applications of metallic-glass systems are continually increasing. Amorphous materials are usually divided into two categories based upon their size. Materials with a thickness and diameter larger than the millimeter (mm) scale are termed as bulk metallic glass (BMG). However, the brittle nature of the bulk-sized samples restricts the size of metallic-glass systems to the micron (µm) or nanometer (nm) range. Metallic glasses with a specimen size in the scale of either µm or nm are defined as thin-film metallic glass (TFMG). In this review, BMGs and TFMGs are termed as metallic glass or MG. A large number of multi-component MGs and their compositional libraries reported by different research groups are summarized in this review. The formation of a multicomponent metallic glass depends on the constituent elements and the fabrication methods. To date, different unique fabrication routes have been adopted to fabricate BMG and TFMGs systems. An overview of the formation principles and fabrication methods as well as advantages and limitations of conventional MG fabrication techniques is also presented. Furthermore, an in-depth analysis of MG inherent properties, such as glass forming ability, and structural, mechanical, thermal, magnetic, and electrochemical properties, and a survey of their potential applications are also described.

Exploring the CAM18 Crystal as a Potential Reference Material for U–Pb Analysis of Zircon

In the process of in situ zircon U–Pb dating, it is an effective means to overcome the matrix effect by using a matrix-matched external reference material. However, the limited number of available zircon reference materials still makes it difficult to meet the research needs. In this paper, we performed a preliminary analysis of the gemological characteristics, trace elements and U–Pb ages of natural zircon CAM18 to assess its suitability as a reference material for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb dating. This tawny, gem-quality zircon has no visible inclusions and weighs approximately 0.55 g. Its density, full width at half maximum (FWHM) of the Raman peak and alpha flux (Dα) indicate that the sample has suffered mild-to-moderate radiation damage without any thermal treatment. The LA-ICP-MS U–Pb dating results reveal that the trace elements content and U–Pb ages of the sample are fairly homogeneous at the 50 μm scale, and there is no obvious loss of radiogenic Pb. The 206Pb/238U age (571.0 ± 3.0 Ma, 2s) and 207Pb/235U age (573.4 ± 6.0 Ma, 2s) are consistent within the analytical uncertainty, and the calculated concordia age is 571.4 ± 1.4 Ma (2s, n = 20). The variation in the 206Pb/238U ages is small, with a measurement repeatability of 0.46% (RSD), which is within the uncertainty of the age accuracy obtained by LA-ICP-MS. The oscillatory zoning, Th/U ratio (0.2) and chondrite-normalized rare-earth element (REE) pattern imply a magmatic origin of zircon CAM18. The Ti-in-zircon temperature ranges from 714 to 742 °C, and the oxygen fugacity ranges from ΔFMQ−2.87 to ΔFMQ−3.17, suggesting that it is crystallized in a reducing environment. All the results show that zircon CAM18 may has great potential in LA-ICP-MS U–Pb dating.

Hierarchical 3D Percolation Network of Ag-Au Core-Shell Nanowire-Hydrogel Composite for Efficient Biohybride Electrodes.

Metal nanomaterials are highly valued for their enhanced surface area and electrochemical properties, which are crucial for energy devices and bioelectronics. However, their practical applications are often limited by challenges, such as scalability and dimensional constraints. In this study, we developed a synthesis method for highly porous Ag-Au core-shell nanowire foam (AACNF) using a one-pot process based on a simultaneous nanowelding synthesis method. The unique characteristics of AACNF as metal-based electrodes show the lowest density among metal-based electrodes while demonstrating high electrical conductivity (99.33-753.04 S/m) and mechanical stability. The AACNF's excellent mass transport properties enable multiscale hierarchical incorporation with functional materials including polymeric precursors and living cells. The enhanced mechanical stability at the nanowelded junctions allows AACNF-hydrogel composites to exhibit large stretching (∼700%) and 10,000 times higher electrical conductivity than hydrogel-nanowire composites without the junction. Large particles in the 1-10 μm scale, including fibroblast cells and exoelectrogenic microbes, are also successfully incorporated with AACNF. AACNF-based microbial fuel cells show high power density (∼330.1 W/m3) within the optimal density range. AACNF's distinctive ability to form a hierarchical structure with substances in various scales showcases its potential for advanced energy devices and biohybrid electrodes in the future.

Influence of Diamond Wire Saw Processing Parameters on the Sawn Surface Characteristics of Silicon Nitride Ceramics.

For the slicing of superhard silicon nitride ceramics, diamond wire sawing technology has great potential for application, and its slicing surface characteristics are an important indicator of cutting quality. In this paper, the sawing experiments of silicon nitride ceramics were carried out within the range of industrial processing parameters of diamond wire sawing (saw wire speed: 800-1600 m/min, workpiece feed speed 0.1-0.4 mm/min). The effects of cutting parameters on the surface morphology, surface roughness and waviness of the as-sawn slices were analyzed. The results show that within the range of sawing parameters for industrial applications, the material on the diamond wire as-sawn surface of silicon nitride ceramics is removed mainly in a brittle mode, with the slice morphology showing brittle pits and regularly distributed wire marks in the 20-55 μm scale range. The surface roughness of the slices along the workpiece feed direction ranges from 0.27 to 0.38 μm and decreases with increasing saw wire speed and decreasing feed rate. The surface waviness ranges from 0.09 to 0.21 μm, which is in good agreement with the changing trend of the sliced-surface roughness. The results of the study provide an experimental reference for promoting the engineering application of diamond wire sawing technology to the processing of silicon nitride ceramic slices.

Enhancement of protein immobilization on polydimethylsiloxane using a synergistic combination of polydopamine and micropattern surface modification

Understanding protein interactions at biointerfaces is critical for the improved design of biomaterials and medical devices. Polydimethylsiloxane (PDMS) is used for numerous device applications, and surface modifications can enhance protein immobilization and the response to cells. A multifunctional approach combining topographical and biochemical modifications was applied to PDMS by fabricating 10–20 µm scale patterns onto PDMS surfaces and by coating with polydopamine (PDA). The modifications were confirmed by surface characterization and bovine serum albumin (BSA), fibrinogen (Fg), and fetuin-A (Fet-A) were radiolabeled with 125I. The amounts of protein attached to the surface before and after elution with sodium dodecyl sulfate (SDS) were quantified from single and complex multi-protein solutions to determine protein stability and competitive binding. The PDA coatings were the most stable and capable of immobilizing the highest levels of all proteins. Furthermore, combinations of PDA coatings with the smallest micropatterns provided an additional improvement, enhancing the amount immobilized and the stability. The adsorption of BSA and Fg from plasma demonstrated competitive binding and possible orientation changes, respectively. It was determined that Fet-A, a less studied protein, adsorbed from plasma at low levels, but the adsorption from fetal bovine serum (FBS) was significantly greater, providing important quantification data from radiolabeling that is relevant to many cell culture studies. Overall, combining topography and PDA modification has a synergistic effect on improving protein immobilization. These findings provide new insight on the quantities of proteins bound to PDMS and PDA coatings with implications for cell interactions in various biotechnology and medical applications.

Output Force Density Saturation in COMSOL Simulations of Biomimetic Artificial Muscles

Many modern applications, such as undersea drones, exoskeletal suits, all-terrain walker drones, prosthetics, and medical augments, would greatly benefit from artificial muscles. Such may be built through 3D-printed microfluidic devices that mimic biological muscles and actuate electrostatically. Our preliminary results from COMSOL simulations of individual devices and small arrays (2 × 2 × 1) established the basic feasibility of this approach. Herein, we report on the extension of this work to N × N × 10 arrays where Nmax = 13. For each N, parameter sweeps were performed to determine the maximal output force density, which, when plotted vs. N, exhibited saturation behavior for N ≥ 10. This indicates that COMSOL simulations of a 10 × 10 × 10 array of this type are sufficient to predict the behavior of far larger arrays. Also, the saturation force density was ~9 kPa for the 100 μm scale. Both results are very important for the development of 3D-printable artificial muscles and their applications, as they indicate that computationally accessible simulation sizes would provide sufficiently accurate quantitative predictions of the force density output and overall performance of macro-scale arrays of artificial muscle fibers. Hence, simulations of new geometries can be done rapidly and with quantitative results that are directly extendable to full-scale prototypes, thereby accelerating the pace of research and development in the field of actuators.

Anti-Reflective Coatings Produced via Atomic Layer Deposition for Hybrid Polymer 3D Micro-Optics.

The increasing demand for optics quality requires the lowest optical power loss, which can occur from unwanted reflections. Laser direct writing (LDW) allows for the fabrication of complex structures, which is particularly advantageous in micro-optic applications. This research demonstrates the possibility of forming an anti-reflective coating on hybrid polymer micro-lenses fabricated by employing LDW without changing their geometry. Such coating deposited via atomic layer deposition (ALD) decreased the reflection from 3.3% to 0.1% at a wavelength of 633 nm for one surface of hybrid organic-inorganic SZ2080™ material. This research validates the compatibility of ALD with LDW 3D multiphoton lithography synergistically, expanding its applications on optical grade sub-100 μm scale micro-optics.

Experimental considerations for integration method of Si thin-film microchips for fluidic self-assembly

Fluidic self-assembly is a technique in which numerous semiconductor chips are integrated spontaneously. Here, we demonstrate that the integration efficiency is significantly improved by optimizing the separation conditions and appropriately controlling the external forces to which the microchips are subjected to the solution. In particular, an external drag force was found to prevent the Si microchips from forming aggregations and prompting transfer to the Si receiver pockets. This resulted in a significant improvement in the integration selectivity. Moreover, experiments with various microchip sizes statistically determined the effect of the Si receiver chip rinse on the evaluation functions: deposition selectivity, yield, and overall yield. While rinsing was effective for fluidic self-assembly of 10 μm scale Si microchips, rinsing of 800 nm scale chips is indicated to have different integration mechanisms. Our quantitative analysis indicated the potential applicability of the fluidic self-assembly technique to the integration technologies of Si micro semiconductor devices.

Spatial and spectral characteristics in realizations of broadband terahertz spectroscopy on a subwavelength scale

In this work, we take aim at the fundamental challenge for realizations of broadband terahertz (THz) spectroscopy on a subwavelength scale. We introduce apertured THz microjets in this effort to resolve the fundamental limits of spatial resolution and spectral bandwidth. The THz microjets are formed as intense foci at the rear of engineered (microcomposite) spheres and are coupled through subwavelength (circular) apertures. Such coupling enables effective transmission of THz power through samples with broad spectral bandwidths and fine spatial resolutions. We show that the apertures function as high-pass filters, with their diameter d enabling strong transmission above a cutoff frequency fc. Our theoretical and experimental results reveal that the values for d and fc are prescribed by a fixed spatial-spectral product dfc, whereby reductions in d (to improve the spatial resolution) can raise fc into the targeted spectrum (at the expense of spectral bandwidth). We use this understanding to demonstrate broadband (0.3–0.7 THz) THz spectroscopy of lactose at the subwavelength (365 µm) scale. These results for apertured THz microjets represent a 20-fold improvement in spatial resolution over analogous apertured THz plane waves. Overall, our findings show promise for studies of carcinogenesis, pathogenesis, and the like.

Supramolecular–Polymer Composite Hydrogels: From In Situ Network Observation to Functional Properties

Abstract Living cells and organisms are composed of numerous biomolecules and control their concentrations and spatial distribution in a spatiotemporal manner to exhibit intricate biological functions. Inspired by the extracellular matrix, synthetic multi-network hydrogels have attracted attention due to their remarkable properties like extremely high toughness. This account summarizes our research progress on one emerging class of the multi-network hydrogels, supramolecular–polymer composite hydrogel. Composite hydrogels can rationally integrate stimulus response of supramolecular gels and stiffness of polymer gels. Super-resolution microscopy visualizes four types of network patterns at the µm scale: an orthogonal and three interactive networks, which may influence the viscoelastic properties of composite hydrogels. We found a kind of composite hydrogel that shows autonomous network remodeling, enabling fracture-induced 3D gel patterning. Furthermore, we demonstrated that supramolecular–polymer composite hydrogels are applicable as a matrix for controlled release of protein biopharmaceuticals in response to antibodies through incorporation of functional molecules such as enzymes and their inhibitors. Supramolecular–polymer composite hydrogels hold promise as the next-generation smart and responsive soft materials for biomedical applications, including tissue engineering and regenerative medicine.