Climbing Plant‐Inspired Micropatterned Devices for Reversible Attachment

Climbing plants have evolved over millions of years and have adapted to unpredictable scenarios in unique ways. These crucial features make plants an outstanding biological model for scientists and engineers. Inspired by the ratchet‐like attachment mechanism of the hook‐climber Galium aparine, a novel micropatterned flexible mechanical interlocker is fabricated using a 3D direct laser lithography technique. The artificial hooks are designed based on a morphometric analysis of natural hooks. They are characterized in terms of pull‐off and shear forces, both in an array and as individual hooks. The microprinted hooks array shows high values of pull‐off forces (up to F_⊥ ≈ 0.4 N cm^?2) and shear forces (up to F_// ≈ 13.8 N cm^?2) on several rough surfaces (i.e., abrasive materials, fabrics, and artificial skin tissues). The contact separation forces of individual artificial hooks are estimated when loads with different orientations are applied (up to F ≈ 0.26 N). In addition, a patterned tape with directional microhooks is integrated into a mobile platform to demonstrate its climbing ability on inclined surfaces of up to 45°. This research opens up new opportunities for prototyping the next generation of mechanical interlockers, particularly for soft‐ and microrobotics, the textile industry, and biomedical fields.     

High‐Throughput Topographic,Mechanical, and Biological Screening of Multilayer Films Containing Mussel‐Inspired Biopolymers

A high‐content screening method to characterize multifunctional multilayer films that combine mechanical adhesion and favorable biological response is reported. Distinct combinations of nanostructured films are produced using layer‐by‐layer methodology and their morphological, physicochemical, and biological properties are analyzed in a single microarray chip. Inspired by the composition of the adhesive proteins in mussels, thin films containing dopamine‐modified hyaluronic acid are studied. Flat biomimetic superhydrophobic patterned chips produced by a bench‐top methodology are used for the build‐up of arrays of multilayer films. The wettability contrasts imprinted onto the chips are allowed to produce individual, position controlled, multilayer films in the wettable regions. The flat configuration of the chip permits to perform a series of nondestructive measurements directly on the individual spots. In situ adhesion properties are directly measured in each spot, showing that nanostructured films richer in dopamine promote the adhesion. In vitro tests show an enhanced cell adhesion for the films with more catechol groups. The advantages presented by this platform include ability to control the uniformity and size of the multilayers films, its suitability to be used as a new low cost toolbox and for high‐content cellular screening, and capability for monitoring in situ a variety of distinct material properties.     

Mussel‐Inspired Electrospun Smart Magnetic Nanofibers for Hyperthermic Chemotherapy

A method for the versatile synthesis of novel, mussel‐inspired, electrospun nanofibers with catechol moieties is reported. These mussel‐inspired nanofibers are used to bind iron oxide nanoparticles (IONPs) and the borate‐containing anticancer drug Bortezomib (BTZ) through a catechol metal binding mechanism adapted from nature. These smart nanofibers exhibit a unique conjugation of Bortezomib to their 1, 2‐benzenediol (catechol) moieties for enabling a pH‐dependent drug delivery towards the cancer cells and the IONPs via strong coordination bonds for exploiting the repeated application of hyperthermia. Thus the synergistic anticancer effect of these mussel‐inspired magnetic nanofibers were tested in vitro for the repeated application of hyperthermia along with the chemotherapy and found that the drug‐bound catecholic magnetic nanofibers exhibited excellent therapeutic efficacy for potential anticancer treatment.     

Cephalopod‐Inspired High Dynamic Range Mechano‐Imaging in Polymeric Materials

Cephalopods, such as squid, cuttlefish, and octopuses, use an array of responsive absorptive and photonic dermal structures to achieve rapid and reversible color changes for spectacular camouflage and signaling displays. Challenges remain in designing synthetic soft materials with similar multiple and dynamic responsivity for the development of optical sensors for the sensitive detection of mechanical stresses and strains. Here, a high dynamic range mechano‐imaging (HDR‐MI) polymeric material integrating physical and chemical mechanochromism is designed providing a continuous optical read‐out of strain upon mechanical deformation. By combining a colloidal photonic array with a mechanically responsive dye, the material architecture significantly improves the mechanochromic sensitivity, which is moreover readily tuned, and expands the range of detectable strains and stresses at both microscopic and nanoscopic length scales. This multi‐functional material is highlighted by creating detailed HDR mechanographs of membrane deformation and around defects using a low‐cost hyperspectral camera, which is found to be in excellent agreement with the results of finite element simulations. This multi‐scale approach to mechano‐sensing and ‐imaging provides a platform to develop mechanochromic composites with high sensitivity and high dynamic mechanical range.     

Stomata‐Inspired Membrane Produced Through Photopolymerization Patterning

The programmed movements of responsive functional hydrogels have received much attention because of their abundant functions and wide range of engineering applications. In this study, an innovative stomata‐inspired membrane (SIM) is fabricated by using a temperature‐responsive hydrogel through a simple, cost‐effective, and high‐throughput patterned photopolymerization. Polymerization‐induced diffusion on the macroscale surface results in formation of a double‐parted polymer membrane with fine pores after single illumination. After heating the SIM, the less deformable thick frame supports the whole structure and the highly deformable thin base regulates pore shape. Among various SIM types, the slit pores of monocot SIM, which are lined up in parallel, exhibit the largest radius deformation. The morphological configuration of the SIM can be easily controlled by changing the photomask for a given application. As the developed SIM features the sensing‐to‐activation functions of stimuli‐responsive hydrogels and can be easily fabricated, this membrane can be potentially used for numerous practical applications, such as filter membranes with adjustable pores, membrane‐based sensors, membrane‐based actuators, and multifunctional membranes.     

Rational Molecular Design of Benzoquinone‐Derived Cathode Materials for High‐Performance Lithium‐Ion Batteries

p‐Benzoquinone (BQ) is a promising cathode material for lithium‐ion batteries (LIBs) due to its high theoretical specific capacity and voltage. However, it suffers from a serious dissolution problem in organic electrolytes, leading to poor electrochemical performance. Herein, two BQ‐derived molecules with a near‐plane structure and relative large skeleton: 1,4‐bis(p‐benzoquinonyl)benzene (BBQB) and 1,3,5‐tris(p‐benzoquinonyl)benzene (TBQB) are designed and synthesized. They show greatly decreased solubility as a result of strong intermolecular interactions. As cathode materials for LIBs, they exhibit high carbonyl utilizations of 100% with high initial capacities of 367 and 397 mAh g^?1, respectively. Especially, BBQB with better planarity presents remarkably improved cyclability, retaining a high capacity of 306 mAh g^?1 after 100 cycles. The cycling stability of BBQB surpasses all reported BQ‐derived small molecules and most polymers. This work provides a new molecular structure design strategy to suppress the dissolution of organic electrode materials for achieving high performance rechargeable batteries.     

Nature‐Inspired Boiling Enhancement by Novel Nanostructured Macroporous Surfaces

World energy crisis has triggered more attention to energy saving and energy conversion systems. Enhanced surfaces for boiling are among the applications of great interest since they can improve the energy efficiency of heat pumping equipment (i.e., air conditioners, heat pumps, refrigeration machines). Methods that are used to make the state‐of‐the‐art enhanced surfaces are often based on complicated mechanical machine tools, are quite material‐consuming and give limited enhancement of the boiling heat transfer. Here, we present a new approach to fabricate enhanced surfaces by using a simple electrodeposition method with in‐situ grown dynamic gas bubble templates. As a result, a well‐ordered 3D macro‐porous metallic surface layer with nanostructured porosity is obtained. Since the structure is built based on the dynamic bubbles, it is perfect for the bubble generation applications such as nucleate boiling. At heat flux of 1 W cm^‐2, the heat transfer coefficient is enhanced over 17 times compared to a plain reference surface. It's estimated that such an effective boiling surface would improve the energy efficiency of many heat pumping machines with 10–30%. The extraordinary boiling performance is explained based on the structure characteristics.     

Hydrogen‐Bonding‐Assisted Intermolecular Charge Transfer: A New Strategy to Design Single‐Component White‐Light‐Emitting Materials

This study reveals the mechanism of the dual‐emission properties for asymmetrical diphenylsulfone and diphenylketone derivatives. A series of asymmetrical diphenylketone and diphenylsulfone derivatives with dual‐emission properties are designed and synthesized. By single crystal structure analyses, various photophysical studies, and 2D ¹H–¹H NOSEY NMR studies, the lower energy emission bands in the dual‐emission spectra are successfully assigned to hydrogen‐bonding‐assisted intermolecular charge transfer emission. The emission properties of these compounds can easily be tuned in both solid state and solution state by destroying or strengthening the intermolecular hydrogen bonding. In addition, thermally activated delayed fluorescence characteristics for the intermolecular charge transfer emissions are also observed. The control of the intermolecular and intramolecular charge transfers serves as the basis for the generation of the white‐light emission. For compound CPzPO, nearly pure white‐light emission with CIE coordinates of (0.31, 0.32) is easily achieved by precipitation from dichloromethane and hexane mixed solvent system. These results clearly give an insight into the dual‐emission properties and provide a rational strategy for the design and synthesis of single‐component white‐light‐emitting materials and mechanoresponsive light‐emitting materials.     

Treefrog Toe Pad‐Inspired Micropatterning for High‐Power Triboelectric Nanogenerator

Inspired by treefrog's toe pads that show superior frictional properties, herein, an industrially compatible approach is reported to make an efficient dielectric tribosurface design using customizable nonclose‐packed microbead arrays, mimicking the friction pads of treefrogs, in order to significantly enhance electrification performance and reliability of triboelectric nanogenerator (TENG). The approach involves using an engineering polymer to prepare a highly ordered large‐area concave film, and subsequently the molding of a convex patterned triboreplica in which the concave film is exploited as a reusable master mold. A nature‐inspired TENG based on the patterned polydimethylsiloxane (PDMS) paired with flat aluminum (Al) can generate a relatively high power density of 8.1 W m^?2 even if a very small force of ≈6.5 N is applied. Moreover, the convex patterned PDMS‐based TENG possesses exceptional durability and reliability over 25 000 cycles of contact–separation. Considering the significant improvements in power generation of TENG; particularly at very small force, together with cost‐effectiveness and possibility of mass production, the present methodology may pave the way for large‐scale blue energy harvesting and commercialization of TENGs for many practical applications.     

Combined Effect of Nitrogen‐ and Oxygen‐Containing Functional Groups of Microporous Activated Carbon on its Electrochemical Performance in Supercapacitors

Microporous activated carbon originating from coconut shell, as received or oxidized with nitric acid, is treated with melamine and urea and heated to 950 °C in an inert atmosphere to modify the carbon surface with nitrogen‐ and oxygen‐containing groups for a systematic investigation of their combined effect on electrochemical performance in 1 M H₂SO₄ supercapacitors. The chemistry of the samples is characterized using elemental analysis, Boehm titration, potentiometric titration, and X‐ray photoelectron spectroscopy. Sorption of nitrogen and carbon dioxide is used to determine the textural properties. The results show that the surface chemistry is affected by the type of nitrogen precursor and the specific groups present on the surface before the treatment leading to the incorporation of nitrogen. Analysis of the electrochemical behavior of urea‐ and melamine‐treated samples reveal pseudocapacitance from both the oxygen and the nitrogen containing functional groups located in the pores larger than 10 Å. On the other hand, pores between 5 Å and 6 Å are most effective in a double‐layer formation, which correlates well with the size of hydrated ions. Although the quaternary and pyridinic‐N‐oxides nitrogen groups have enhancing effects on capacitance due to the positive charge, and thus an improved electron transfer at high current loads, the most important functional groups affecting energy storage performance are pyrrolic and pyridinic nitrogen along with quinone oxygen.     

Squaraine‐Doped Functional Nanoprobes: Lipophilically Protected Near‐Infrared Fluorescence for Bioimaging

Hydrophobically stabilized near‐IR fluorescence from self‐assembled nanoprobes composed of amphiphilic poly(maleic anhydride‐alt‐octadec‐1‐ene) (PMAO) and lipophilized squaraine dopants is reported. From comparative studies with varying lipophilicity of squaraine dyes as well as of nanoparticulate polymer matrices, it is found that dual protection by simultaneous lipophilization of the dye‐polymer pair greatly improves the chemical stability of labile squaraine dyes, to produce efficient NIR fluorescence in physiological aqueous milieux. The surface properties of negatively charged PMAO nanoparticles are readily modified by coating with an amine‐rich cationic glycol chitosan with biofunctionality. Efficient cellular imaging and in vivo sentinel lymph node mapping with size and surface‐controlled nanoprobes demonstrate that lipophilic dual protection of NIR fluorescence and the underlying functional nanoprobe approach hold great potential for bioimaging applications.     

Polyol‐Mediated Synthesis of Nanoscale Functional Materials

Nanoscale functional materials such as luminescent materials (ZnS:Ag⁺, Cl^–; LaPO₄:Ce³⁺,Tb³⁺; Y₂O₃:Eu³⁺), color pigments (CoAl₂O₄; Cr₂O₃; ZnCo₂O₄; (Ti_0.85Ni_0.05Nb_0.10)O₂; α‐Fe₂O₃; Cu(Fe,Cr)O₄; TiO₂), transparent conducting oxides (ZnO:In³⁺), and catalytically active oxides (CeO₂; Mn₃O₄; V₂O₅) are prepared with the polyol method. All these materials are yielded as crystalline, spherical, and almost monodisperse particles, 30–200 nm in size. Characterization is carried out based on scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), optical spectroscopy, and conductance measurements. The preparation via the polyol method is singled out due to its broad and easy applicability. The resulting material properties are similar to or better than nanoscale materials prepared by other measures. Some materials and their properties, e.g., ZnS:Ag⁺,Cl^– as a phosphor, ZnCo₂O₄ and Cu(Fe,Cr)O₄ as pigments, and ZnO:In³⁺ as transparent conductive oxide, are presented for the first time at the nanoscale.     

New Iron‐Containing Electrode Materials for Lithium Secondary Batteries

Using a galvanostatic charge/discharge cycler and cyclic voltammetry, we investigated for the first time the electrochemical properties of iron‐containing minerals, such as chalcophanite, diadochite, schwertmannite, laihuite, and tinticite, as electrode materials for lithium secondary batteries. Lithium insertion into the mineral diadochite showed a first discharge capacity of about 126 mAh/g at an average voltage of 3.0 V vs. Li/Li+, accompanied by a reversible capacity of 110 mAh/g at the 60th cycle. When the cutoff potential was down to 1.25 V, the iron was further reduced, giving rise to a new plateau at 1.3 V. Although the others showed discharge plateaus at low potentials of less than 1.6 V, these results give an important clue for the development of new electrode materials.     

An Underwater Surface‐Drying Peptide Inspired by a Mussel Adhesive Protein

Water hampers the formation of strong and durable bonds between adhesive polymers and solid surfaces, in turn hindering the development of adhesives for biomedical and marine applications. Inspired by mussel adhesion, a mussel foot protein homologue (mfp3S‐pep) is designed, whose primary sequence is designed to mimic the pI, polyampholyte, and hydrophobic characteristics of the native protein. Noticeably, native protein and synthetic peptide exhibit similar abilities to self‐coacervate at given pH and ionic strength. 3,4‐dihydroxy‐l ‐phenylalanine (Dopa) proves necessary for irreversible peptide adsorption to both TiO₂ (anatase) and hydroxyapatite (HAP) surfaces, as confirmed by quartz crystal microbalance measurements, with the coacervate showing superior adsorption. The adsorption of Dopa‐containing peptides is investigated by attenuated total reflection infrared spectroscopy, revealing initially bidentate coordinative bonds on TiO₂, followed by H‐bonded and eventually long‐ranged electrostatic and Van der Waals interactions. On HAP, mfp3s‐pep‐3Dopa adsorption occurs predominantly via H‐bond and outersphere complexes of the catechol groups. Importantly, only the Dopa‐bearing compounds are able to remove interfacial water from the target surfaces, with the coacervate achieving the highest water displacement arising from its superior wetting properties. These findings provide an impetus for deve­loping coacervated Dopa‐functionalized peptides/polymers adhesive formulations for a variety of applications on wet polar surfaces.     

Nanogold‐Loaded Sharp‐Edged Carbon Bullets as Plant‐Gene Carriers

The higher DNA delivery efficiency into plants by gold nanoparticles embedded in sharp carbonaceous carriers is demonstrated. These nanogold‐embedded carbon matrices are prepared by heat treatment of biogenic intracellular gold nanoparticles. The DNA‐delivery efficiency is tested on a model plant, Nicotiana tabacum, and is further extended to the monocot, Oryza sativa, and a hard dicot tree species, Leucaena leucocephala. These materials reveal good dispersion of the transport material, producing a greater number of GUS foci per unit area. The added advantages of the composite carrier are the lower plasmid and gold requirements. Plant‐cell damage with the carbon‐supported particles is very minimal and can be gauged from the increased plant regeneration and transformation efficiency compared with that of the commercial micrometer‐sized gold particles. This is ascribed to the sharp edges that the carbon supports possess, which lead to better piercing capabilities with minimum damage.     

Simultaneous Reduction and Surface Functionalization of Graphene Oxide by Mussel‐Inspired Chemistry

This study presents a method of simultaneous reduction and surface functionalization of graphene oxide by a one‐step poly(norepinephrine) functionalization. The pH‐induced aqueous functionalization of graphene oxide by poly(norepinephrine), a catecholamine polymer inspired by the robust adhesion of marine mussels, chemically reduced and functionalized graphene oxide. Moreover, the polymerized norepinephrine (pNor) layer provided multifunctionality on the reduced graphene oxide that includes surface‐initiated polymerization and spontaneous metallic nanoparticle formation. This facile surface modification strategy can be a useful platform for graphene‐based nano‐composites.     

Nepenthes Pitcher Inspired Anti‐Wetting Silicone Nanofilaments Coatings: Preparation,Unique Anti‐Wetting and Self‐Cleaning Behaviors

Nepenthes pitcher inspired anti‐wetting coatings, fluoro‐SNs/Krytox, are successfully fabricated by the combination of fluoro‐silicone nanofilaments (fluoro‐SNs) and Krytox liquids, perfluoropolyethers. Fluoro‐SNs with different microstructure are grown onto glass slides using trichloromethylsilane by simply repeating the coating step, and then modified with 1H,1H,2H,2H‐perfluorodecyltrichlorosilane. Subsequently, the Krytox liquid is spread on the fluoro‐SNs coatings via capillary effect. The fluoro‐SNs/Krytox coatings feature ultra‐low sliding angle for various liquids, excellent stability, and transparency. The sliding speed of liquid drops on the fluoro‐SNs/Krytox coating is obviously slower than on the lotus inspired superhydrophobic and superoleophobic coatings, and is controlled by composition of the coating (e.g., morphology of the fluoro‐SNs, type of Krytox and its thickness) and properties of the liquid drops (e.g., density and surface tension). In addition, the self‐cleaning property of the fluoro‐SNs/Krytox coating is closely related to properties of liquid drops and dirt.     

Bio‐Inspired Multifunctional Metallic Foams Through the Fusion of Different Biological Solutions

Nature is a school for scientists and engineers. Inherent multiscale structures of biological materials exhibit multifunctional integration. In nature, the lotus, the water strider, and the flying bird evolved different and optimized biological solutions to survive. In this contribution, inspired by the optimized solutions from the lotus leaf with superhydrophobic self‐cleaning, the water strider leg with durable and robust superhydrophobicity, and the lightweight bird bone with hollow structures, multifunctional metallic foams with multiscale structures are fabricated, demonstrating low adhesive superhydrophobic ­self‐cleaning, striking loading capacity, and superior repellency towards different corrosive solutions. This approach provides an effective avenue to the development of water strider robots and other aquatic smart devices floating on water. Furthermore, the resultant multifunctional metallic foam can be used to construct an oil/water separation apparatus, exhibiting a high separation efficiency and long‐term repeatability. The presented approach should provide a promising solution for the design and construction of other multifunctional metallic foams in a large scale for practical applications in the petro‐chemical field. Optimized biological solutions continue to inspire and to provide design idea for the construction of multiscale structures with multifunctional integration.     

Functional Graphenic Materials Via a Johnson−Claisen Rearrangement

Current research in materials has devoted much attention to graphene, with a considerable amount of the chemical manipulation going through the oxidized state of the material, known as graphene oxide (GO). In this report, the hydroxyl functionalities in GO, the vast majority that must be allylic alcohols, are subjected to Johnson?Claisen rearrangement conditions. In these conditions, a [3, 3] sigmatropic rearrangement after reaction with triethyl orthoacetate gives rise to an ester functional group, attached to the graphitic framework via a robust C?C bond. This variation of the Claisen rearrangement offers an unprecedented versatility of further functionalizations, while maintaining the desirable properties of unfunctionalized graphene. The resultant functional groups were found to withstand reductive treatments for the deoxygenation of graphene sheets and a resumption of electronic conductivity is observed. The ester groups are easily saponified to carboxylic acids in situ with basic conditions, to give water‐soluble graphene. The ester functionality can be further reacted as is, or the carboxylic acid can easily be converted to the more reactive acid chloride. Subsequent amide formation yields up to 1 amide in 15 graphene carbons and increases intergallery spacing up to 12.8 Å, suggesting utility of this material in capacitors and in gas storage. Other functionalization schemes, which include the installation of terminal alkynes and dipolar cycloadditions, allow for the synthesis of a highly positively charged, water‐soluble graphene. The highly negatively and positively charged graphenes (zeta potentials of ?75 mV and +56 mV, respectively), are successfully used to build layer‐by‐layer (LBL) constructs.