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Abstract: Anisotropic microstructures are widely used by being cleverly designed to achieve important functions. Mammals' respiratory tract is filled with dense cilia that rhythmically swing back and forth in a unidirectional wave to propel mucus and harmful substances out of the lung through larynx. Inspired by the ciliary structure and motion mechanism of the respiratory tract systems, a viscoelastic microsphere transporting strategy based on integration of airway cilium‐like structure and magnetically responsive flexible conical arrays is demonstrated. Under external magnetic fields, the viscoelastic microspheres can be directionally and continuously transported alongside the swing of the cilia‐like arrays that contain magnetic particles. This work provides a promising route for the design of advanced medical applications in directional transport of microspheres, drug delivery systems, ciliary dyskinesia treating, and self‐cleaning without liquid. [ABSTRACT FROM AUTHOR]

Single-molecule force spectroscopy techniques are powerful tools for investigating the mechanical unfolding of biomolecules. However, they are limited in throughput and require dedicated instrumentation. Here, we report a force-generating particle that can unfold target molecules on-demand. The particle consists of a plasmonic nanorod core encapsulated with a thermoresponsive polymer shell. Optical heating of the nanorod leads to rapid collapse of the polymer, thus transducing light into mechanical work to unfold target molecules. The illumination tunes the duration and degree of particle collapse, thus controlling the lifetime and magnitude of applied forces. Single-molecule fluorescence imaging showed reproducible mechanical unfolding of DNA hairpins. We also demonstrate the triggering of 50 different particles in <1 min, exceeding the speed of conventional atomic force microscopy. The polymer force clamp represents a facile and bottom-up approach to force manipulation. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms that lead to the formation of petroleum crude oil in water emulsion is fundamental for the development of sustainable exploitation procedures and efficient oil spills remediation technologies. In this study we surveyed the effectiveness of different nitrogen-containing organic bases in promoting emulsification through the interaction with the naphthenic acid fraction present in crude oil. It was found that bulky secondary amines were the most effective, able to stabilize the emulsion at 10 wt% of oil content for more than 20 min, and the emulsion at 40 wt% for more than 5 h. Interfacial tension measurements indicated that the interaction was effective even when naphtenic acids were dosed at very low levels (total acid number lass than 0.3). It was also observed that a successive addition of carbon dioxide to the system readily induced the breaking of the emulsion, probably by affecting the equilibrium involved in the formation of the naphthenates stabilizing species. In the light of these findings, we tested polyethylene glycols bearing a terminal amino moiety as a new class of CO 2 responsive emulsifiers suitable for the petroleum industry. [ABSTRACT FROM AUTHOR]

Abstract: Recently, smart surfaces with switchable wettability have aroused much attention. However, only single surface chemistry or the microstructure can be changed on these surfaces, which significantly limits their wetting performances, controllability, and applications. A new surface with both tunable surface microstructure and chemistry was prepared by grafting poly(N‐isopropylacrylamide) onto the pillar‐structured shape memory polymer on which multiple wetting states from superhydrophilicity to superhydrophobicity can be reversibly and precisely controlled by synergistically regulating the surface microstructure and chemistry. Meanwhile, based on the excellent controllability, we also showed the application of the surface as a rewritable platform, and various gradient wettings can be obtained. This work presents for the first time a surface with controllability in both surface chemistry and microstructure, which starts some new ideas for the design of novel superwetting materials. [ABSTRACT FROM AUTHOR]

• This review shows the advanced and relevant technical specifications of fiber optic detection technology for VOC gas. • This review summarizes the gas-responsive materials and some advanced film deposition techniques of fiber optic VOCs sensors. • This review presents the sensing principles, performance, and applications of fiber optic VOC gas sensors. • This review discusses the existing challenges and potential applications of fiber optic VOCs sensors. • This review can help to keep the reader informed of the latest advances in the field. Most volatile organic compounds (VOCs) are toxic, carcinogenic, and mutagenic, and can have serious effects on human health and the ecological environment. Therefore, the detection and identification of VOCs have an urgent need in both indoor and outdoor environments. Fiber optic sensors, as intrinsically safe, miniature, portable, immune to electromagnetic interference, and easy to remote sensing and multiplexing sensing technology, are utilized in VOC gas sensing promising to provide new approaches to overcome the limitations of conventional gas sensing systems. This review assesses recent research advances in fiber optic VOC gas sensors, including various sensing principles, gas-responsive materials, new techniques for sensing material deposition, structures, and applications. Fiber optic VOC gas sensors are classified and discussed based on different principles. In addition, this paper extensively reviews the recent advances in fiber optic VOC gas sensors and discusses the strategies and approaches to further their development. [ABSTRACT FROM AUTHOR]

Using variable temperature 2H static NMR spectra and 13C spin-lattice relaxation times (T1), we show that two different porous organic cages with tubular architectures are ultra-fast molecular rotors. The central para-phenylene rings that frame the 'windows' to the cage voids display very rapid rotational rates of the order of 1.2-8×106 Hz at 230 K with low activation energy barriers in the 12-18 kJ mol−1 range. These cages act as hosts to iodine guest molecules, which dramatically slows down the rotational rates of the phenylene groups (5-10×104 Hz at 230 K), demonstrating potential use in applications that require molecular capture and release. [ABSTRACT FROM AUTHOR]

Rational design and elaborate modular construction of interfacial architectures in which molecular transport is mediated by responsive/adaptive nanostructures has become a growing and fertile field of research in supramolecular materials chemistry. This work presents, for the first time, the use of PNIPAM-capped mesoporous silica thin films as thermosensitive cation-selective mesochannels. Thus far, this feature has only been observed in thermosensitive biological channels. The interfacial architecture created here accomplishes its specific functions through the concerted or simultaneous action of spatially addressed subunits with temperature response and ion exclusion capabilities. The thermo-perm-selectivity effect stems from the synergistic interplay between the pH-dependent electrostatic characteristics of the silica scaffold and the thermo-controlled steric effects introduced by the capping brush layer. It is hoped that the 'nanoarchitectonic' approach presented here will provide new routes toward the generation of heterosupramolecular nanosystems displaying addressable transport properties similar to those encountered in biological ion channels. [ABSTRACT FROM AUTHOR]

A novel poly( N-isopropylacrylamide- co-acryloylamidobenzo-12-crown-4) (PNB) microgel with rapid γ-cyclodextrin (CD)-responsive characteristics and adsorption property is developed. The microgel is composed of benzo-12-crown-4 (B12C4) units as molecule-recognition receptors and poly( N-isopropylacrylamide) networks as phase-transition actuators as well as adsorbent backbone chains. The PNB microgels significantly increase their volumes induced by γ-CD, and adsorb γ-CD molecules within PNB networks because of formation of γ-CD/B12C4 inclusion complexes. Detection of γ-CD-concentration and the molecule-specific adsorption processes of the microgels are investigated systematically. The PNB microgels provide a new tool for rapid concentration measurement and effective separation of γ-CD. [ABSTRACT FROM AUTHOR]

Despite a growing interest in two-dimensional polymers, their rational synthesis remains a challenge. The solution-phase synthesis of a two-dimensional polymer is reported. A DNA-based monomer self-assembles into a supramolecular network, which is further converted into the covalently linked two-dimensional polymer by anthracene dimerization. The polymers appear as uniform monolayers, as shown by AFM and TEM imaging. Furthermore, they exhibit a pronounced solvent responsivity. The results demonstrate the value of DNA-controlled self-assembly for the formation of two-dimensional polymers in solution. [ABSTRACT FROM AUTHOR]

The structure of certain nonliving tissues determines their self-shaping and self-folding capabilities in response to a stimulus. Predetermined movements are realized according to changes in the environmental conditions due to the generated stresses of the multilayer anisotropic structure. In this study, we present bioinspired responsive anisotropic multilayer films and their fabrication process which comprises low-cost techniques. The anisotropic multilayer materials are capable of deforming their geometry caused by small temperature changes (

Eukaryotic cells have inner compartments (organelles), each with distinct properties and functions. One mimic of this architecture, based on biopolymers, is the multicompartment capsule (MCC). Here, MCCs in which the inner compartments are chemically unique and "smart," i.e., responsive to distinct stimuli in an orthogonal manner are created. Specifically, one compartment alone is induced to degrade when the MCC is contacted with an enzyme while other compartments remain unaffected. Similarly, just one compartment gets degraded upon contact with reactive oxygen species generated from hydrogen peroxide (H 2 O 2 ). And thirdly, one compartment alone is degraded by an external, physical stimulus, namely, by irradiating the MCC with ultraviolet (UV) light. All these specific responses are achieved without resorting to complicated chemistry to create the compartments: the multivalent cation used to crosslink the biopolymer alginate (Alg) is simply altered. Compartments of Alg crosslinked by Ca 2+ are shown to be sensitive to enzymes (alginate lyases) but not to H 2 O 2 or UV, whereas the reverse is the case with Alg/Fe 3+ compartments. These results imply the ability to selectively burst open a compartment in an MCC "on-demand" (i.e., as and when needed) and using biologically relevant stimuli. The results are then extended to a sequential degradation, where compartments in an MCC are degraded one after another, leaving behind an empty MCC lumen. Collectively, this work advances the MCC as a platform that not only emulates key features of cellular architecture, but can also begin to capture rudimentary cell-like behaviors., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)

ABSTRACT This Highlight presents an overview of the rapidly growing field of dynamic covalent polymers. This class of polymers combines intrinsic reversibility with the robustness of covalent bonds, thus enabling formation of mechanically stable, polymer-based materials that are responsive to external stimuli. It will be discussed how the inherent dynamic nature of the dynamic covalent bonds on the molecular level can be translated to the macroscopic level of the polymer, giving access to a range of applications, such as stimuli-responsive or self-healing materials. A primary distinction will be made based on the type of dynamic covalent bond employed, while a secondary distinction will be based on the consideration whether the dynamic covalent bond is used in the main chain of the polymer or whether it is used to allow side chain modification of the polymer. Emphasis will be on the chemistry of the dynamic covalent bonds present in the polymer, in particular in relation to how the specific (dynamic) features of the bond impart functionality to the polymer material, and to the conditions under which this dynamic behavior is manifested. © 2016 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3551-3577. [ABSTRACT FROM AUTHOR]

Two important aspects of actuation behavior of stimuli-responsive hydrogels are the complexity of the shape change and its speed. Here, it is shown that varying the shape of simple polymer bilayers can result in very complex and very fast spontaneous folding. The complexity and high folding rate arise from the choice of the shape and from the presence of inhomogeneous swelling within the thermoresponsive layer entrapped between the top hydrophobic layer and the substrate. In contrast to homogeneous swelling of a freestanding bilayer, which leads to a gradual increase of curvature throughout the whole bilayer, inhomogeneous swelling first results in complete rolling of the periphery of the film, which changes its mechanical properties and affects the subsequent morphing process. Further swelling of the thermoresponsive layer generates more stress that builds up until a buckling threshold is overcome, allowing very fast switching from the flat edge-rolled configuration into a folded one. The research demonstrates how the introduction of holes into actuating bilayers gives rise not only to a novel geometric control over the folding fate of the films but also adds the ability to tune the rate of folding, through the careful selection of hole size, location, and shape. [ABSTRACT FROM AUTHOR]

We report composite stimulus-responsive cholesteric catalytically active microgels derived from filamentous supramolecular building blocks: cellulose nanocrystals (CNCs). The variation in the microgel dimensions and pitch in response to the change in ambient conditions was governed by the polymer component. The cholesteric morphology of the microgels resulted from the self-organization of CNCs in spherical confinement. The microgels exhibited excellent structural integrity and functioned as microreactors in catalytic hydrolysis reactions and in the synthesis of metal nanoparticles. Because of these collective properties, the reported microgels show much promise for application in the design of functional responsive materials. [ABSTRACT FROM AUTHOR]

The benzoic imine is a dynamic covalent bond, which is stable around neutral pH value (ca. 7.4), but starts to hydrolyze at the extracellular pH value of solid tumors (ca. 6.5) and rapidly disintegrates at endosome and lysosome pH values (ca. 4.5-6.5). This characteristic is promising for the construction of physiological-pH-responsive materials, such as polymeric micelles, nanoparticles, and hydrogels for pharmaceutical and tissue-engineering applications. This Focus Review summarizes recent progress in the design and synthesis of pH-sensitive materials that contain the benzoic imine bond with biomedical objectives. [ABSTRACT FROM AUTHOR]

Responsive materials have been investigated for a lot of applications such as smart devices and sensors, which change shape, color, transparency, or functionality when stimulated by external stimuli. However, the practical applications of responsive materials have been largely hampered by their irreversible transitions under limited stimuli such as temperature, pH, and chemical. As a result, a lot of research has been paid to improve the reversibility of chromatism and deformation. In this review, the recent research of responsive materials based on aligned carbon nanotubes is described, with the focus on the responsive materials in response to light and electricity. [ABSTRACT FROM AUTHOR]

This study reports a simple and versatile synthesis route for the preparation of highly uniform and densely functionalized aqueous microgels by modification of latex particles composed of an active ester monomer (pentafluorophenyl acrylate; PFPA). The hydrophobic nature of the PFPA allows synthesizing very uniform latex particles via emulsion polymerization, whose size can be controlled by the surfactant concentration, while the degree of crosslinking is a function of the added crosslinker. The high reactivity of the PFPA groups toward nucleophilic substitution delivers a platform method to synthesize functional microgels by reaction with functional amines. This study demonstrates this process for the dense functionalization of the entire particle with an amine carrying a pH-responsive unit. This study further describes the influence of the crosslinking degree on the ability for swelling of the resulting microgels in aqueous dispersion. [ABSTRACT FROM AUTHOR]

[Display omitted] • A polymer-filled ZnS@SiO 2 photonic crystal (thickness ∼ 700 nm) was fabricated. • The photonic crystal presented a sensitive thermochromism larger than 30 nm/°C. • The thermochromism can occur in the air rather than immersed in water. • The reflectivity is long-term stable when it was exposed to dry environments. • This ultrathin photonic crystal was used to prepare thermochromic smart fabrics. Thermochromic photonic crystals (PC) have been extensively studied owing to their potential applications in displays, smart windows, sensors, and anti-counterfeiting devices. However, the poor water-retention capacity of the traditional hydrogel-based thermoresponsive PCs makes them unstable, and their color change is realized by immersion in water. Although polymer elastomer-based PC can increase stability, their response range as well as sensitivity is dramatically decreased. In this study, an ultrathin polymer-filled ZnS@SiO 2 PC film with long-term stability and ultrasensitive thermochromism is presented. The polymer provides the film with excellent stability, and the ultrathin PC structure ensures that the film exhibits distinguished thermochromism in air rather than in water, owing to condensation. The structural color changed from violet to near-infrared, and the change in the reflection wavelength was as high as 300 nm when the temperature decreased from 15 °C to 5 °C. Furthermore, an ultrathin PC layer was applied to fabricate thermochromic smart fabrics. This work demonstrates the design and fabrication of ultrathin PC films, as well as their ultrasensitive response and high stability, presenting a platform for combining different types of functionalized polymer materials and achieving more ingenious responsive effects. [ABSTRACT FROM AUTHOR]

A straightforward method to increase the refractive index of photocrosslinkable polymers by incorporation of high index inorganic nanoparticles is demonstrated and shown to enhance the reflection efficiency of thermochromic 1D photonic multilayers. The refractive index of spin-coated and UV-crosslinked films based on poly( para-methyl styrene) (P pMS) copolymers is increased from 1.57 for the copolymer alone to as high as 1.67 for nanocomposite samples with a volume fraction of 0.38 of ZrO2 nanoparticles. Thermochromic photonic multilayers consisting of alternating films of P pMS-ZrO2 with poly( N-isopropylacrylamide) (PNIPAM) copolymers shows the increases in reflectance as large as 2.5-fold compared to P pMS/PNIPAM multilayers lacking particles. In addition, ZrO2 nanoparticles are used to increase the refractive index of PNIPAM-based films up to 1.68 with a volume fraction of 0.49 of nanoparticles, enabling the fabrication of alternating PNIPAM-ZrO2/PNIPAM multilayers with a well-defined Bragg peak that shifts from 635 nm at 6 °C to 410 nm at 48 °C, and reflectance intensities as high as ≈0.30. [ABSTRACT FROM AUTHOR]

Supramolecular functional materials able to respond to external stimuli have several advantages over their classical covalent counterparts. The preparation of soft actuators with the ability to respond to external stimuli in a spatiotemporal fashion, to self-repair, and to show directional motion, is currently one of the most challenging research goals. Herein, we report a series of metallopolymers based on zinc(II)-terpyridine coordination nodes and bearing photoisomerizable diazobenzene units and/or solubilizing luminescent phenylene-ethynylene moieties. These supramolecular polymers act as powerful gelating agents at low critical gelation concentrations. The resulting multiresponsive organogels display light-triggered mechanical actuation and luminescent properties. Furthermore, owing to the presence of dynamic coordinating bonds, they show self-healing abilities. [ABSTRACT FROM AUTHOR]

The possibility to control molecular systems with light holds much promise for the fields of materials life sciences. To achieve such control, compounds that are able to reversibly photoisomerize between two states or more can be employed. Several classes of photochromic units are available depending on which properties should be modulated upon isomerization, e.g., electronic gap, polarity, or geometry. The latter class, which is mostly based on E/Z isomerization, is particularly useful to remotely trigger motion at the single molecule level, giving rise to a wide range of applications at all scales after incorporation into the adequate architecture. In this article, recent advances in that direction are highlighted, including our own efforts to optimize the intrinsic properties of azobenzene photoswitches, as well as their integration into oligomers, polymers, and 3D frameworks. [ABSTRACT FROM AUTHOR]

Porous polymer membranes made via electrostatic complexation are fabricated from a water-soluble poly(ionic liquid) (PIL) for the first time. The porous structure is formed as a consequence of simultaneous phase separation of the PIL and ionic complexation with an acid, which occurred in a basic solution of a nonsolvent for the PIL. These membranes have a stimuli-responsive porosity, with open and closed pores in isopropanol and in water, respectively. This property is quantitatively demonstrated in filtration experiments, where water is passing much slower through the membranes than isopropanol. [ABSTRACT FROM AUTHOR]

In recent decades, the design and construction of smart materials capable of switching into a polyzwitterionic state by an external trigger have been intensively pursued. Polyzwitterionic states have unique antifouling and surface properties and external triggers, such as pH, light, ions, electric field and CO2, cause significant changes in materials with regard to overall charge, ionic strength and wettability. This survey highlights current progress in the irreversible as well as the reversible switching process involving polyzwitterionic moieties, which can, in turn, be applied to studying the interaction of various interfaces with biological species as protein, DNA, bacteria or platelets and also for advanced use. [ABSTRACT FROM AUTHOR]

A simple method to prepare temperature-sensitive films composed of micrometer-sized colloidal hydrogel particles using evaporating drops of colloidal suspensions is demonstrated. The films range in thickness from a monolayer to approximately fifty particle diameters depending on initial particle volume fraction. Sessile droplets of hydrogel-particle suspensions are evaporated on silicon wafers. The film is formed from particles spread densely over the air-water interface which then cross-link and are deposited on the surface during the evaporation process. The resultant thin films exhibit a temperature-responsiveness characteristic of the individual particles permitting modulation of size, shape, porosity, and optical transmission. [ABSTRACT FROM AUTHOR]

Water is the driving force of all nature. Securing freshwater has been one of the most important issues throughout human history, and will be important in the future, especially in the next decade. Fog is ubiquitous in nature and is therefore considered as an alternative and sustainable freshwater resource. Nature has long served as a source of inspiration to develop new fog-harvesting technologies. However, the collection of freshwater from static fog is still a challenge for the existing bio-inspired fog-harvesting systems. Herein, magnetically induced fog harvesting under windless conditions through the integration of cactus-inspired spine structures and magnetically responsive flexible conical arrays is reported. Under an external magnetic field, static fog can be spontaneously and continuously captured and transported from the tip to the base of the spine due to the Laplace pressure difference. This work demonstrates the advantage of collecting fog water, especially in windless regions, which provides a new avenue for fog harvesting and can serve as a source of inspiration to further optimizations of existing fog-water-harvesting strategies. [ABSTRACT FROM AUTHOR]

Infectious complications occur in a minor but significant portion of the patients undergoing joint replacement surgery or fracture fixation, particularly those with severe open fractures, those undergoing revision arthroplasty or those at elevated risk because of poor health status. Once established, infections are difficult to eradicate, especially in the case of bacterial biofilm formation on implanted hardware. Local antibiotic carriers offer the prospect of controlled delivery of antibiotics directly in target tissues and implant, without inducing toxicity in non-target organs. Polymeric carriers have been developed to optimize the release and targeting of antibiotics. Passive polymeric carriers release antibiotics by diffusion and/or upon degradation, while active polymeric carriers release their antibiotics upon stimuli provided by bacterial pathogens. Additionally, some polymeric carriers gelate in-situ in response to physiological stimuli to form a depot for antibiotic release. As antibiotic resistance has become a major issue, also other anti-infectives such as silver and antimicrobial peptides have been incorporated in research. Currently, several antibiotic loaded biomaterials for local infection prophylaxis are available for use in the clinic. Here we review their advantages and limitations and provide an overview of new materials emerging that may overcome these limitations. [ABSTRACT FROM AUTHOR]

Dual responsive inverse opal hydrogels were designed as autonomous sensor systems for (bio)macromolecules, exploiting the analyte-induced modulation of the opal's structural color. The systems that are based on oligo(ethylene glycol) macromonomers additionally incorporate comonomers with various recognition units. They combine a coil-to-globule collapse transition of the LCST type with sensitivity of the transition temperature toward molecular recognition processes. This enables the specific detection of macromolecular analytes, such as glycopolymers and proteins, by simple optical methods. While the inverse opal structure assists the effective diffusion even of large analytes into the photonic crystal, the stimulus responsiveness gives rise to strong shifts of the optical Bragg peak of more than 100 nm upon analyte binding at a given temperature. The systems' design provides a versatile platform for the development of easy-to-use, fast, and low-cost sensors for pathogens. [ABSTRACT FROM AUTHOR]

Numerous examples of material systems that dynamically interact with and adapt to the surrounding environment are found in nature, from hair-based mechanoreceptors in animals to self-shaping seed dispersal units in plants to remodeling bone in vertebrates. Inspired by such fascinating biological structures, a wide range of synthetic material systems have been created to replicate the design concepts of dynamic natural architectures. Examples of biological structures and their man-made counterparts are herein revisited to illustrate how dynamic and adaptive responses emerge from the intimate microscale combination of building blocks with intrinsic nanoscale properties. By using top-down photolithographic methods and bottom-up assembly approaches, biologically inspired dynamic material systems have been created 1) to sense liquid flow with hair-inspired microelectromechanical systems, 2) to autonomously change shape by utilizing plantlike heterogeneous architectures, 3) to homeostatically influence the surrounding environment through self-regulating adaptive surfaces, and 4) to spatially concentrate chemical species by using synthetic microcompartments. The ever-increasing complexity and remarkable functionalities of such synthetic systems offer an encouraging perspective to the rich set of dynamic and adaptive properties that can potentially be implemented in future man-made material systems. [ABSTRACT FROM AUTHOR]

Natural materials possess many distinctive "living" attributes, such as self-growth, self-healing, environmental responsiveness, and evolvability, that are beyond the reach of many existing synthetic materials. The emerging field of engineered living materials (ELMs) takes inspiration from nature and harnesses engineered living systems to produce dynamic and responsive materials with genetically programmable functionalities. Here, we identify and review two main directions for the rational design of ELMs: first, engineering of living materials with enhanced performances by incorporating functional material modules, including engineered biological building blocks (proteins, polysaccharides, and nucleic acids) or well-defined artificial materials; second, engineering of smart ELMs that can sense and respond to their surroundings by programming dynamic cellular behaviors regulated via cell–cell or cell–environment interactions. We next discuss the strengths and challenges of current ELMs and conclude by providing a perspective of future directions in this promising area. Existing strategies for the design of engineered living materials (ELMs). Various chassis cells (bacterial, yeast, mammalian, and fungal cells) can be developed into ELMs through two design principles: functional module incorporation and dynamic behavior regulation. Functional module incorporation refers not only to the functional modification of endogenous biological building blocks (proteins, polysaccharides, and nucleic acids), but also to the combination of functional exogenous artificial materials (e.g., hydrogels, conductive materials, and nanoparticles) with living systems. Dynamic behavior regulation exploits the capacity of living systems to regulate their own behavior in response to cues from other cells or from the external environment, aiming at manufacturing advanced responsive and self-patterning living materials. [Display omitted] • Introduction of endogenous or exogenous functional modules endows ELMs with emerging properties. • Programming cell–cell or cell–environment interactions enables dynamic living materials. • ELMs composed of multicellular consortia exhibit intrinsic advantages including resource sharing and division of labor. • Machine learning techniques accelerate the design of functional modules and genetic circuits for ELMs. [ABSTRACT FROM AUTHOR]

Microfluidic valves based on chemically responsive materials have gained considerable attention in recent years. Herein, a wireless enantio-responsive valve triggered by bipolar electrochemistry combined with chiral recognition is reported. A conducting polymer actuator functionalized with the enantiomers of an inherently chiral oligomer was used as bipolar valve to cover a tube loaded with a dye and immersed in a solution containing chiral analytes. When an electric field is applied, the designed actuator shows a reversible cantilever-type deflection, allowing the release of the dye from the reservoir. The tube can be opened and closed by simply switching the polarity of the system. Qualitative results show the successful release of the colorant, driven by chirality and redox reactions occurring at the bipolar valve. The device works well even in the presence of chemically different chiral analytes in the same solution. These systems open up new possibilities in the field of microfluidics, including also controlled drug delivery applications., (© 2022 Wiley Periodicals LLC.)

The development of photoinduced luminescent radicals with dynamic emission color is still challenging. Herein we report a novel molecular radical system (TBIQ) that shows photo-controllable luminescence, leading to a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ is decorated with steric-demanding tertiary butyl groups that enable appropriate intermolecular interaction to make dynamic intermolecular coupling possible for controllable behaviors. We reveal that the helicenic pseudo-planar conformation of TBIQ experiences a planarization process after light excitation, leading to more compactly stacked supermolecules and thus generating radicals via intermolecular charge transfer. The photo-controllable luminescent radical system is employed for a high-level information encryption application. This study may offer unique insight into molecular dynamic motion for optical manufacturing and broaden the scope of smart-responsive materials for advanced applications., (© 2022 Wiley-VCH GmbH.)

Buildings must adapt and respond dynamically to their environment to reduce their energy loads and mitigate environmental impacts. Several approaches have addressed responsive behavior in buildings, such as adaptive and biomimetic envelopes. However, biomimetic approaches lack sustainability consideration, as conducted in biomimicry approaches. This study provides a comprehensive review of biomimicry approaches to develop responsive envelopes, aiming to understand the connection between material selection and manufacturing. This review of the last five years of building construction and architecture-related studies consisted of a two-phase search query, including keywords that answered three research questions relating to the biomimicry and biomimetic-based building envelopes and their materials and manufacturing and excluding other non-related industrial sectors. The first phase focused on understanding biomimicry approaches implemented in building envelopes by reviewing the mechanisms, species, functions, strategies, materials, and morphology. The second concerned the case studies relating to biomimicry approaches and envelopes. Results highlighted that most of the existing responsive envelope characteristics are achievable with complex materials requiring manufacturing processes with no environmentally friendly techniques. Additive and controlled subtractive manufacturing processes may improve sustainability, but there is still some challenge to developing materials that fully adapt to large-scale and sustainability needs, leaving a significant gap in this field.

Herein we show that dispersing inorganic cesium lead bromide (CsPbBr 3 ) perovskite quantum dots (QDs) in optical quality films, possessing an accessible and controlled pore size distribution, gives rise to fluorescent materials with a controlled and highly sensitive response to ambient changes. A scaffold-based synthesis approach is employed to obtain ligand-free QDs, whose pristine surface endows them with high sensitivity to the presence of different vapors in their vicinity. At the same time, the void network of the host offers a means to gradually expose the embedded QDs to such vapors. Under these conditions, the luminescent response of the QDs is mediated by the mesostructure of the matrix, which determines the rate at which vapor molecules will adsorb onto the pore walls and, eventually, condensate, filling the void space. With luminescence quantum yields as high as 60%, scaffold-supported ligand-free perovskite nanocrystals display intense photoemission signals over the whole process, as well as high photo- and chemical stability, which allows illuminating them for long periods of time and recovering the original response upon desorption of the condensed phase. The results herein presented open a new route to explore the application of perovskite QD-based materials in sensing.

We study the role of temperature on the structure of pure polymer brushes and their mixture with attractive nanoparticles in flat and cylindrical geometries. It has previously been established that the addition of such nanoparticles causes the polymer brush to collapse and the intensity of the collapse depends on the attraction strength, the nanoparticle diameter, and the grafting density. In this work, we carry out molecular dynamics simulation under good solvent conditions to show how the collapse transition is affected by the temperature, for both plane grafted and inside-cylinder grafted brushes. We first examine the pure brush morphology and verify that the brush height is insensitive to temperature changes in both planar and cylindrical geometries, as expected for a polymer brush in a good solvent. On the other hand, for both system geometries, the brush structure in the presence of attractive nanoparticles is quite responsive to temperature changes. Generally speaking, for a given nanoparticle concentration, increasing the temperature causes the brush height to increase. A brush which contracts when nanoparticles are added eventually swells beyond its pure brush height as the system temperature is increased. The combination of two easily controlled external parameters, namely, concentration of nanoparticles in solution and temperature, allows for sensitive and reversible adjustment of the polymer brush height, a feature which could be exploited in designing smart polymer devices.

In recent years, significant advances have been made in the field of functionalized membranes. With the functionalization using various materials, such as polymers and enzymes, membranes can exhibit property changes in response to an environmental stimulation, such as heat, light, ionic strength, or pH. The resulting responsive nature allows for an increased breadth of membrane uses, due to the developed functionalization properties, such as smart-gating filtration for size-selective water contaminant removal, self-cleaning antifouling surfaces, increased scalability options, and highly sensitive molecular detection. In this review, new advances in both fabrication and applications of functionalized membranes are reported and summarized, including temperature-responsive, pH-responsive, light-responsive, enzyme-functionalized, and two-dimensional material-functionalized membranes. Specific emphasis was given to the most recent technological improvements, current limitations, advances in characterization techniques, and future directions for the field of functionalized membranes., Competing Interests: 8.Conflict of interest The authors declare no conflict of interest at this time.

ABSTRACT Climbing lizards display numerous advanced features in their locomotion, notably a method to quickly switch between a state of low and high adhesive force capacity. Inspired by the gecko's adhesive switching, a method of mechanically switching between low and high adhesive states is reported. In particular, the first switching of an adhesive system using only a change in system compliance is demonstrated. Mechanical clamping and a novel magnetic clamping system are used to switch an iron/PDMS composite adhesive between a soft and rigid state. The switch in compliance directly influences the maximum load of the adhesive as measured in lap-shear. Notably, contact area and the contact chemistry remain unaltered despite significant changes in force capacity. The demonstration of a compliance-only switching mechanism has broad implications for understanding natural adhesive systems-especially in organisms that can dynamically alter their rigidity (e.g. cells). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 48-57 [ABSTRACT FROM AUTHOR]