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Lightweight, flexible and highly conductive electromagnetic interference (EMI) shielding materials are of great importance for protecting flexible electronics and telecommunication devices under extremely high temperature conditions. A potential solution is to incorporate ceramic phases with highly conductive flexible carbon nanotube films to improve their thermal stability. However, the grain size of the ceramic phase generally increased significantly as the temperature increased which led to brittleness. In this work, a highly flexible carbon nanotube (CNT) film with controllable ceramic nanocrystals was prepared by precursor infiltration and pyrolysis. The silicon carbide (SiC) grain size in the nanocomposites was inhibited by the spatial confinement effects of CNT networks and a second amorphous SiBCN phase. The SiC grain size in the composite film decreased with the increase of the SiBCN content and the elongation at break of the nanocomposites improved significantly by 45 %. Moreover, the initial thermogravimetric temperature of the prepared films has been significantly improved to exceed 600 °C compared to the raw CNT film. Importantly, the nanocomposite film exhibited an average EMI shielding effectiveness of ∼40 dB from 8.2 to 12.4 GHz. Benefiting from the ultrafine grain size, the nanocomposite films could be folded and extended without micro-cracks over 1000 times. Combining the performance and mechanical properties of the nanocomposite film, this approach provides important guidance for designing high-performance CNT-based electromagnetic shielding materials with superior flexibility at elevated temperatures. [ABSTRACT FROM AUTHOR]

Lanthanum nickel oxide (LaNiO 3, LNO) films exhibit excellent electrical conductivity but poor mechanical properties, considerably limiting their further development in the field of flexible electronics. In this study, flexible LNO thin films of different thicknesses were fabricated on a unique two-dimensional (2D) mica platform using a simple metal organic deposition technique. The obtained LNO films exhibited a pseudocubic phase without impurities. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterisations proved that the films were well-crystallised, dense, and flat, with controllable thickness. In addition, the flexible LNO/mica element possesses low resistivity (5 × 10−4 Ω cm), translucency, and good bending resistance. The electrical resistivity can remain stable under various bending radii (r = 10∼2 mm), thousands of bending cycles, and a wide temperature range (28–200 °C), demonstrating good durability, mechanical stability and temperature resistance. Furthermore, a ferroelectric BiFeO 3 film was constructed based on the obtained conductive LNO electrode, which exhibited typical ferroelectric characteristics. This excellent performance suggests that the flexible LNO electrode is promising for flexible electronic applications. [ABSTRACT FROM AUTHOR]

In the era of the artificial intelligence, flexible multifunctional films that combine optical transparency, electrical conductivity, and ferromagnetism are highly beneficial for many advanced applications. Herein, we fabricated a flexible magnetic transparent conductor molybdenum doped indium oxide (IMoO) thin film on a mica substrate using a pulsed laser deposition (PLD) technique. The valence states of Mo dopants were determined to be Mo4+ and Mo6+ by X-ray photoelectron spectroscopy (XPS) analysis. From the measured optical transmittance spectrum, average visible (Vis) and near-infrared (NIR) transmittance (T ave_Vis and T ave_NIR) values in IMoO film are calculated to be 85.9 % and 85.4 %, respectively. The IMoO film shows an electron mobility (μ e) of around 113 cm2 V−1 s−1 and a sheet resistance (R s) of 69 Ω. We illustrate the benefits of Mo doping, which leads to increased NIR transparency and μ e compared to commercially available tin-doped indium oxide (ITO). On the other hand, the IMoO film shows clear magnetic hysteretic behaviors at room temperature, indicating the presence of ferromagnetism. The main origin of the ferromagnetism is presumably attributed to the Mo4+ ions with an electronic configuration of 4 d2. Bending cyclic tests reveal favourable mechanical durability and bending stability in the IMoO/mica films. Our systematic investigation demonstrates that IMoO film possesses a superior optoelectronic performance beyond ITO, Mn-doped indium oxide (IMnO), and Sn-Mn-codoped indium oxide (ITMnO), substantiating the potential of the IMoO/mica film as a high-performance transparent conductive magnetic material for flexible optoelectronic and spintronic applications. [ABSTRACT FROM AUTHOR]

A cooperative strategy for simultaneously improving typically conflict properties between mechanical strength and self-healability of elastomers is developed by combining the strong electron-withdrawing and high free-volume effects of fluorine atoms, resulting in the highest recorded puncture energy (648.0 mJ) elastomer so far. [Display omitted] There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually exclusive. Herein, we design and fabricate a fluorinated phenolic polyurethane (FPPU) elastomer based on octafluoro-4,4′-biphenol to overcome this challenge. This fluorine-based motif not only tunes interchain interactions through π−π stacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine atoms. The developed FPPU elastomer shows the highest recorded puncture energy (648.0 mJ), high tensile strength (27.0 MPa), as well as excellent self-healing efficiency (92.3%), along with low surface energy (50.9 MJ m−2), notch-insensitivity, and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane (BPPU) elastomer. Taking advantage of the above-mentioned merits of FPPU elastomer, we prepare an anti-fouling triboelectric nanogenerator (TENG) with a self-healable, and reprocessable elastic substrate. Benefiting from stronger electron affinity of fluorine atoms than hydrogen atoms, this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU elastomer. Furthermore, a healable and stretchable conductive composite is prepared. This research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The advancement of flexible electronics demands improved components, necessitating heat dissipation membranes (HDMs) to exhibit high thermal conductivity while maintaining structural integrity and performance stability even after extensive deformation. Herein, we have devised a laser-modulated reduction technique for graphene oxide (GO), enabling the fabrication of high-quality, large-scale, low-defect graphene, which yields high-performance HDMs after orderly deposition. The work underscores the crucial role of the laser wavelength and dispersion liquid's coupling intensity in influencing the morphology and properties of graphene. Optimal coupling effect and energy conversion are realized when a laser of 1064 nm wavelength irradiates a triethylene glycol (TEG)/ N , N -Dimethylformamide (DMF) dispersion. This unique synergy generates high transient energy, which facilitates the deprotonation process and ensures a swift, comprehensive GO reduction. In contrast to conventional water-based laser reduction methods, the accelerated reaction magnifies the size of the graphene sheets by mitigating the ablation effect. After membrane construction with an ordered structure, the corresponding membrane exhibits a high thermal conductivity of 1632 W m−1 K−1, requiring only ∼1/10 of the total preparation time required by other reported methods. Remarkably, the resulting HDM demonstrates superior resilience against creasing and folding, maintaining excellent smoothness and negligible reduction in thermal conductivity after violent rubbing. The combination of exceptional flexibility and thermal conductivity in HDMs paves the way for long-term practical use in the flexible electronics industry. [ABSTRACT FROM AUTHOR]

Recently, cubic perovskite SrTMO 3 (TM = V, Nb, and Mo) compounds have attracted great interest as correlated transparent conducting oxides (CTCOs). However, in theory, none of these three oxides is capable of completely covering the entire visible (Vis) light wavelength range with transparency. Herein, epitaxial orthorhombic CaMoO 3 thin films were grown on flexible mica substrates using a pulsed laser deposition (PLD) method. By exploiting the tilting of MoO 6 octahedra, an optimal balance between plasma energy (ћω p) and electrical conductivity (σ) was realized in CaMoO 3. Electronic transport characterizations indicated that the σ value of CaMoO 3 is comparable to that of SrTMO 3. The optical transmittance spectra demonstrated that the CaMoO 3 film possesses superior Vis transparency compared to SrTMO 3. From the ellipsometry analysis, it was found that the O 2p – V 3d interband transition occurs at around 4.16 eV while the screened plasma energy (ћω p) is approximately 1.37 eV. The favorable absorption edges for both the long and short wavelength regions ensure the high transparency of CaMoO 3 across the entire Vis spectrum. Additionally, bending cyclic tests illustrated the excellent mechanical durability and endurance of the CaMoO 3 /mica films. The present work is instructive for exploring alternative CTCOs beyond SrTMO 3 , demonstrating that the optimal balance between ћω p and σ can be realized by manipulating the TMO 6 octahedral tilting to improve the transparent conducting performance of correlated perovskite-type oxides. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D printing inks into liquid bath anti-solvent forms fibers in designated locations. • Structural and electronic properties are tunable by the anti-solvent. • Coiled carbon nanotube yarns stretch up to 50 % with under 1 % change in resistance. • Printed nanotube yarns have specific conductivity on par with metals. Inspired by methods of wet fiber spinning, we introduce a process using a 3D printer to create dense carbon nanotube (CNT) fibers and extensible coils with metal-like DC specific conductivity. An extrusion-based printer with an immersed nozzle extrudes a homogeneous shear-thinning ink (with initially < 1 % CNT concentration in water) into a liquid bath of antisolvent, inducing immediate precipitation-driven solidification slightly beyond the nozzle tip. This process forms continuous fibers of CNTs with conductivity up to 3 × 105 S/m, exceeding that of dense graphite and approaching that of CNTs spun from similar inks in a continuous fiber spinning process (6 × 105 S/m). The specific conductivity is up to 1 × 103 S m2/kg, comparable with gold (2.3 × 103 S m2/kg). The printing regimes are analyzed, with consideration of the draw ratio imposed during printing. Particular focus is placed on adjusting the speed of counter-diffusion of the ink solvent and the bath liquid, which allows for tuning of fiber diameter, conductivity, and specific conductivity respectively over ranges of one, four, and five orders of magnitude. The conductivity of resulting fibers is maximized when the speed of solvent counter-diffusion is high and the radius reduction is largest. When extrusion speed is also high relative to speed of the nozzle motion, a fluid mechanical coiling instability emerges which creates filaments with periodic coils, allowing for intricate designs to be formed along a linear extrusion path. Once dried, these densely coiled structures initially maintain their shape and can subsequently undergo up to 50 % strain with under 1 % change in resistance and 170 % linear extension with 20 % increase in resistance as the coils unwind. The resulting complex coil structures have applications in lightweight circuitry and as flexible interconnects. [ABSTRACT FROM AUTHOR]

Nowadays, flexible transparent conductors (TCs) have been widely applied for solar cells, stretchable integrated circuits, sensor networks, and human-machine interaction devices. Recently, nondoped correlated metallic oxides (CMOs) have aroused great interest as indium-free TCs. In this work, an all-inorganic flexible CMO thin film with an ultrahigh figure of merit (FOM) value was fabricated using a simple preparation technology: the direct deposition of epitaxial SrNbO 3 thin films on a stratiform mica substrate via a pulsed laser deposition (PLD) process. From the measured optical transmittance (Tr) spectra in conjunction with the ellipsometic data, it is found that SrNbO 3 film possesses a superior visible light transparency compared with commonly investigated SrVO 3 due to its larger bandgap. The charge transport measurements indicate that the dc electrical conductivity (σ) of SrNbO 3 is higher than that of SrVO 3 , attributed presumably to a weaker electron correlation and therefore a smaller effective electron mass (m *) in SrNbO 3. Bending cyclic tests reveals high mechanical durability and bending stability in SrNbO 3 films. This detailed investigation demonstrates a great potential of the all-inorganic flexible epitaxial SrNbO 3 /mica film as an indium-free TC with high performance for future optoelectronic applications. [ABSTRACT FROM AUTHOR]

The increasing global energy consumption and carbon emissions propelled the demand for materials possessing excellent thermal insulation and fire resistance. In this study, we prepared mullite nanofiber membranes (MNFMs) by electrospinning using polyethylene oxide and polyvinyl alcohol as dual templates. This method endows MNFMs with good flexibility and overcomes the inherent brittleness of ceramic fibers. And ensure that it can maintain structural integrity even when bent or folded without fragmentation or crushing. Simultaneously, the prepared MNFMs exhibit a lightweight and fluffy porous structure (0.02195 g cm−3), showing a remarkably low thermal conductivity of 0.035 W m−1 K−1. Moreover, it demonstrates excellent high-temperature resistance, withstanding temperatures as high as 1300 °C, and exceptional thermal insulation. The unique combination of these characteristics qualifies the MNFMs for a wide range of applications, such as high-temperature insulation, fire resistance, high-temperature filtration, flexible electronics, and high-temperature protective clothing. [ABSTRACT FROM AUTHOR]

[Display omitted] Soft polymer gels encounter difficulties in meeting the demanding requirements of real-life applications due to the long-standing challenge to reproduce the excellent mechanical properties and multifunctionalities observed in natural soft tissues. Here, a skin-like hierarchically structured organo-hydrogel with an all-around performance that matches and outperforms mammalian skin is reported, including high stretchability of 2227% strain, remarkable strength of 20.78 MPa, record-breaking fracture toughness up to 260 MJ/m3, together with excellent resistance to fracture and fatigue (fatigue threshold over 30.4 kJ/m2), superior long-term stability and tolerance to freezing and elevated temperatures. It also shows high conductivity and excellent electrical sensing capability. The underlying synergistic multi-scale reinforcement mechanisms of the organo-hydrogel are also validated via molecular dynamics simulations and experimental results. Hence, this work formulates a model design applicable to various polymer gels to expand their potential in applications including flexible electronics, multi-functional bionic sensors, energy storage devices and soft robotics. [ABSTRACT FROM AUTHOR]

To further enhance the mechanical endurance of ZnO–Cu–ZnO (ZCZ) films and CuZnSnS (CZTS) solar cells with deposited ZCZ films (ZCZ CSCs), Ag elements were introduced into metallic layers of ZCZ films using magnetron sputtering Cu–Ag co-sputtering techniques. The Ag addition effectively reduced the stresses generated during the growth of the Cu film, resulting in the suppression of three-dimensional island growth and the formation of a more uniform metallic film. Specifically, ZnO–Cu/Ag(35 W)–ZnO (ZCA35Z) films exhibited an average transmittance (T -ave) of 89%, outperforming the ZCZ film with a T -ave of 80%, achieved by increasing the continuity of metallic layers. Moreover, ZCA35Z CSCs demonstrated a higher power conversion efficiency (PCE) value of 6.38% compared to ZCZ CSCs (6.01%) without bending. Additionally, the PCE value of ZCA35Z CSCs showed a 9% improvement over ZCZ CSCs at a bending diameter of 10 mm. Remarkably, even after 1000 bending cycles, the PCE value of ZCA35Z CSCs exhibited a substantial 15% enhancement compared to ZCZ CSCs, which can be attributed to the continuous Cu films enhancing carrier migration and reducing optical losses. This new method to enhance the mechanical endurance of ZCZ films and ZCZ CSCs by increasing Cu film continuity via Cu–Ag co-sputtering presents a promising approach to boost the performance of flexible electronics. [Display omitted] • ZCZ films' optical and electrical properties were enhanced by improving Cu film continuity. • The average transmittance of ZCAZ films is up to 89.05%. • The films show an ultra-low resistivity of 1.19 × 10-4 Ω cm at 35W Ag power. • PCE of ZCA35Z CSCs was improved by 15% compared to ZCZ CSCs with 1000 bending cycles. • ZCAZ film enabling flexible CZTS solar cells with desirable mechanical endurance. [ABSTRACT FROM AUTHOR]

Enabling the future of interconnected devices through miniature sensors and functional materials. [Display omitted] The advent of the Internet of Things and smart applications such as smart cities, smart health care, and smart electronics will require the use of a vast array of sensors. Sensors are a key part of the revolution in interconnected devices. The growing need for sensing, monitoring, and collecting data at scales from small to large will help, for example, prevent future pandemics, elucidate climate change, optimize industrial processes, and train machine learning models. Recent progress in materials science, micro/nano technologies, and integrated circuits has made it possible to reduce the size and cost of sensors while integrating them into more complex machines, ranging from wearable/implantable devices to onboard laboratories for planetary exploration rovers. However, the small dimensions of miniature sensors present some challenges, including power supply, active sensing materials, and material flexibility. In this article, we review microbatteries to power miniature sensors. We discuss materials and architectures for microbatteries and their fabrication methods. We also discuss energy harvesting materials for self-powered miniature sensors. We review in detail advanced materials for active sensing, including organic, inorganic, and composite materials with emphasis on wearable/implantable sensors targeted at humans and animals. In addition, flexible electronics as well as substrates and encapsulation materials and their integration are reviewed. Finally, future perspectives and challenges of these functional materials for next-generation miniature sensors are highlighted. [ABSTRACT FROM AUTHOR]

[Display omitted] The flexible electronics is a fast-moving, emerging interdisciplinary research that involves the use of organic/inorganic functional materials, electronic component designs, and their integration fabrication. Here, we review recent advancements in flexible piezoelectronics and 3D printing preparation, including (i) flexible piezoelectric materials suitable for 3D printing, their piezoelectric properties, and a comparison among them, (ii) 3D-printed flexible piezoelectronics with increasing capabilities in sensing, energy harvesting, and electronic display, and (iii) 3D printing technology and preparation methods, such as inkjet printing, thermal or laser-assisted direct writing printing (DIW), and fused deposition molding (FDM), which enable rapid design and manufacture of new flexible electronic devices. We also summarize the design methods of flexible piezoelectric devices based on 3D printing technology, and discuss their extensive applications in smart wearable electronics, flexible circuits, the Internet of Things, and software robots. Flexible piezoelectronics is a rapidly advancing field that is poised to have a significant impact on the modern industrial structure and human life. Finally, we prospect for the future development of 3D printing flexible piezoelectronics and the challenges that researchers may encounter. [ABSTRACT FROM AUTHOR]

Printed electronic technologies have sparked interest worldwide because of their capacity to transcend the limitations of existing high-cost electronics based on the fabrication of various devices deploying flexible substrates. Fabricating electrodes on stretchable, bendable, and soft substrates plays a vital role in flexible electronics. Hence this study demonstrates an electrochemical flexible substrate-based aptamer sensor for the Chikungunya virus (CHIKV) antigen over an extensive range of concentrations. In brief, ZnO nanorods were chemically synthesised and characterised by Field emission scanning electron microscopy (FESEM), UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and X-Ray Diffraction (XRD), providing biocompatibility to the aptamer, a biorecognition element. The aptasensor showed a wide linearity (1 ng/ml-10 μg/ml), deploying a voltammetric identification in the presence of 10 mM methylene blue act as a redox-transition substance, with an estimated limit of detection of 1 ng/ml and 25 s as its optimal response time. The applicability of the sensor was further demonstrated by introducing CHIKV-Antigen into commercial serum samples. The built-in sensor has a shelf-life of approximately a month. CHIKV-Antigen can be detected rapidly on a portable platform. As a result, CHIKV can be diagnosed more quickly, allowing for more effective treatment choices. [Display omitted] • In-house, a flexible glove based three electrode system was developed. • Chemically synthesized and thoroughly characterized zinc oxide nanorods were utilized. • The built electrochemical sensor performed in human serum efficiently. • This sensor could be used to diagnose Chikungunya virus antigen. • The application of the Dengue Virus protein confirmed cross-reactivity. [ABSTRACT FROM AUTHOR]

A major challenge for integration of functional oxides, such as ferroelectrics, into microelectronics and flexible electronics is the reduction of their processing temperature, which needs to be lower than the degradation temperature of silicon and flexible plastic substrates. Aiming that, attention has been given to low-temperature processing of oxide films by chemical solution deposition (CSD). In the field of ferroelectrics, potassium sodium niobate ((K 1−x Na x)NbO 3 , KNN) has aroused a special interest due to its eco-friendliness, despite the high crystallization temperature. In this work, polycrystalline KNN thin films have been fabricated for the first time at a temperature as low as 400 °C using a modified CSD process, the Seeded Photosensitive Precursor Method (SPPM). Despite this low processing temperature, monophasic and stoichiometric films with appreciable values of remnant polarization, P r ∼ 10.8 μC/cm2, and hysteretic piezoresponse are obtained. These results open a window to the direct integration of KNN films into the high-performance electronic devices. [ABSTRACT FROM AUTHOR]

Polymer based resistive switching (RS) is one of the most rapidly growing memory technology that is being developed for next-generation flexible/wearable devices. In this work, we have chosen two types of host polymer matrix to support the Pb-free Cs 2 AgBiBr 6 double perovskite nanofillers. Selection of poly(methyl methacrylate) (PMMA) and polyethylene oxide (PEO) is based on their nature of insulating and ionic conductivity respectively. To eliminate the dominance of electrode on (RS), Au and ITO were chosen as top and bottom electrode respectively. The PEO based device with or without nanofiller did not show significant differences in device performance. On the contrary, substantial impact of nanofiller in PMMA based devices could be observed. Interestingly, with the concentration of 2% Cs 2 AgBiBr 6 nanofillers in both the polymer matrix, the devices exhibited adequate bipolar memory switching behavior. However, the PMMA composite device (with 2% nanofiller) exhibited excellent RS properties such as low operating voltage, high current ON/OFF ratio, long endurance and retention in both normal and bending mode. Low value of ON/OFF ratio in PEO composite device could be attributed to higher conductivity of PEO polymer matrix that result into high current in the OFF state. Finally, the indispensable results in the PMMA nanocomposite based flexible device was hypothesized by using energy band diagram on the basis of charge trapping/de-trapping inside the functional matrix and pave the way for the development of next-generation flexible electronics. [ABSTRACT FROM AUTHOR]

Recently, correlated metallic oxide (CMO) was proposed as a brand-new design strategy for transparent conductors (TCs). Among these CMOs, perovskite-type SrVO 3 with an electronic configuration of 3 d1 has been most investigated. Herein, the SrMoO 3 films, one 4 d2 perovskite CMO, were deposited on a flexible mica substrate using a pulsed laser deposition method. Our experimental results indicate that the SrMoO 3 film possesses a superior optoelectronic performance compared with SrVO 3 , owing to the weaker electronic correlations and 4 d2 electronic configuration in SrMoO 3. Bending cyclic tests indicate that the flexible SrMoO 3 /mica film has a high mechanical bending durability and stability. This 4 d2 SrMoO 3 /mica film demonstrates a great potential as a high-performance TC for flexible optoelectronics. [ABSTRACT FROM AUTHOR]

[Display omitted] Shape memory materials can maintain temporary shapes without external constraints and revert to their permanent shape upon exposure to an external stimulus, such as heat, light, or moisture. This behavior, often named the shape memory effect, has led to the use of shape memory materials in a variety of applications including deployable aerospace structures, biomedical devices, flexible electronics, and untethered soft robots. Most thermally triggered reconfigurable metamaterials using shape memory polymers require a laborious process of thermomechanical programming at high temperature, above their transition value, to maintain a temporary shape. In this paper, we utilize two 3D-printable polymeric materials that do not rely upon their shape memory effect to generate robust shape memory response in a set of mechanical metamaterials. The enabling characteristic is the mismatch of the temperature-dependent moduli of the constitutive materials leveraged in rationally interconnected reconfigurable units, and their hallmark is the freedom to forego the complex programming process of typical shape memory polymers. Their shape reconfiguration and rapid recovery are solely governed by mechanical loading and temperature change, leading to sequentially programmable multistability, hyperelasticity, giant thermal deformations, and shape memory capacity. Theoretical models, numerical simulations, and thermomechanical experiments are performed to demonstrate their functionality, stability transition mechanism, and potential applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Electronic skins detect external variables and have applications in smart scenarios. However, an isolated device is limited by its intrinsic properties and is only applicable in a limited number of cases. Electronic skins still face challenges in achieving multimodal performance while improving their key parameters. Therefore, multifunctional materials and device architectures are essential in multimodal electronic skins for efficient transfer of external stimuli into electrical signals. This review elaborates on the ideas and specific methods for constructing multimodal electronic skins from the following four aspects: distinguishing external stimuli, decomposing external stimuli, suppressing interference, and decoupling electrical output. The review focuses on sensing materials, mechanisms, structures, and signal decoupling in multimodal electronic skins. Conclusions concerning the effective approaches to immediate problems and potential opportunities in multimodal electronic skins are also provided. [ABSTRACT FROM AUTHOR]

Biopolymer-based conductive hydrogels (HGs) are promising candidates for preparing environmentally friendly flexible electronics. However, it is still a great challenge to synthesize biopolymer-based tough, self-healable, and fast strain recoverable HGs. Herein, a facile strategy is demonstrated to synthesize stretchable, self-recoverable, conductive, and tough HGs strain sensors through the formation of multi-dynamic interactions (i.e., imine bond formation, hydrogen bonds, ionic bonds, and electrostatic bonds) and strong covalent interactions between MXene (Ti 3 C 2 T x), oxidized sodium alginate (OSA), chitosan (CS), polyacrylamide (PAAm), Fe(III) and PEDOT:PSS. Thus, obtaining dynamically and covalently bonded nanocomposite hydrogels (NCHGs) with controllable interfacial interactions exhibited a high mechanical strength (0.91 MPa), toughness (2.99 MJ/m3), stretchability (820 %), elasticity (>600 %) and conductivity (1.31 S/m). In addition, the presence of Fe(III) ions and conducting fillers endows excellent repeatability with high stability in resistance change upon bending or stretching with ultra-broad sensitivity up to 11-gauge factor and consisting lowest resistance change up to 0.5 %. [Display omitted] • Multi-component-based nanocomposite hydrogels possessing multi-varient bonds in single system. • Formation of ionic and dynamic covalent bonds between two biopolymers imparting a fast self-recovery to bare HGs and NCHGs. • NCHGs consisting fracture strain up to 820 %, 0.91 MPa of fracture stress, 2.99 MJ/m3 toughness, and >600 % elasticity. [ABSTRACT FROM AUTHOR]

The two-point bending test is a valuable test for estimating the strength of the thin and flexible glass/ceramic parts that are increasingly used in next-generation flexible electronics devices. We present closed-form expressions for determining Weibull material scale parameters and probability of failure for the two-point bending test. The presented solution, tested on Corning® Willow® glass samples, eliminates the need for iterative and often time-consuming approaches (e.g., Finite Element Analysis) for estimating scale parameters. Considering the strength-controlling flaw distribution on a surface or inside a volume, the solution assumes that the Weibull modulus (m) and scaling modulus (m A or m V) are distinct quantities to ensure the scale parameter is independent of the applied load. This condition reveals a special relationship between the moduli that is unique to two-point bending given its highly non-uniform state of stress, which contrasts with other uniaxial bending tests (such as three and four-point bending) in which both moduli have the same numerical value. [Display omitted] • Closed-form expression for scaled strength and probability of failure for the two-point bending test. • Calculation accounts for survival stress history of sample. • Weibull modulus and Weibull scaling modulus reveal a special relationship. • A good agreement between probability of failure obtained from test data, closed-form and FEA. [ABSTRACT FROM AUTHOR]

[Display omitted] Oxide ceramic microfibers with low thermal conductivity, high temperature, and corrosion resistance have been widely used in the field of thermal insulation. When the fiber diameter is reduced to the nanoscale (<1000 nm), the high specific surface area and porosity brought by the diameter refinement endow these nanofibers with unique thermal, optical, electrical and other properties, which are expected to be applied in advanced high-tech fields. Oxide ceramic micro-nanofibers (MNFs) belong to a new structural ceramic system, but they suffer from intrinsic hardness and brittleness. We have been committed to developing new textile technologies and fabricating flexible oxide ceramic MNFs. In this review, the development status of oxide ceramic MNFs and their applications are first briefly summarized. Then, the definition of flexibility and flexibility mechanisms of MNFs, as well as the strategies and methods for fabricating flexible oxide ceramic MNFs are comprehensively discussed. Finally, our perspective on the future development of oxide ceramic MNFs is proposed. We suppose that they will develop toward the direction of flexibility, porosity, multifunctionality, thin film, and aerogels, and their functional applications will permeate from the traditional heat insulation to the emerging fields such as flexible electronics and batteries, intelligent artificial muscle, and industrial catalysis. [ABSTRACT FROM AUTHOR]

In recent years, there has been considerable attention devoted to flexible electronic devices within the realm of biomedical engineering. These devices demonstrate the capability to accurately capture human physiological signals, thereby facilitating efficient human-computer interaction, and providing a novel approach of flexible electronics for monitoring and treating related diseases. A notable contribution to this domain is the emergence of conductive hydrogels as a novel flexible electronic material. Renowned for their exceptional flexibility, adjustable electrical conductivity, and facile processing, conductive hydrogels have emerged as the preferred material for designing and fabricating innovative flexible electronic devices. This paper provides a comprehensive review of the recent advancements in flexible electronic devices rooted in conductive hydrogels. It offers an in-depth exploration of existing synthesis strategies for conductive hydrogels and subsequently examines the latest progress in their applications, including flexible neural electrodes, sensors, energy storage devices and soft robots. The analysis extends to the identification of technological challenges and developmental opportunities in both the synthesis of new conductive hydrogels and their application in the dynamic field of flexible electronics. • The most important thing is that at the end of each section, we not only summarize this section, but also put forward many of our own opinions and prospects for future research directions, which are not mentioned in most reviews. • Advancing the Field of Conductive Hydrogels Synthesis: This article presents a comprehensive exploration of cutting-edge techniques in the synthesis of conductive hydrogels, shedding light on the use of innovative materials such as MXene, liquid metals, and so forth. • Pioneering Applications of Conductive Hydrogels in Biology: Our work provides a comprehensive survey of the design and utilization of flexible neural electrodes, sensors, and other devices built upon the foundation of conductive hydrogels. • Shaping the Future of Conductive Hydrogels and Flexible Electronics: Building upon the systematic review of current research, this article offers a forward-looking perspective on potential enhancements. • We propose avenues for optimizing the performance of conductive hydrogel materials and fostering innovation in the realm of flexible electronic devices. [ABSTRACT FROM AUTHOR]

Flexible wearable smart sensing materials have gained immense momentum, and biomass-based hydrogel sensors for renewable and biologically safe wearable sensors have attracted significant attention in order to meet the growing demand for sustainability and ecological friendliness. Cellulose has been widely used in the field of biomass-based hydrogel sensing materials, being the most abundant biomass material in nature. This review mainly focuses on the types of cellulose hydrogels, the preparation methods and their applications in smart flexible sensing materials. The structure-functional properties-application relationship of cellulose hydrogels and the applications of various cellulose hydrogels in flexible sensing are described in detail. Then it focuses on the methods and mechanisms of cellulose hydrogel flexible sensors preparation, and then summarizes the research of cellulose hydrogel sensors for different types of stimulus response mechanisms to pressure, pH, biomolecules, ions, temperature, humidity, and light. The applications of cellulose hydrogels as flexible sensing materials in biomedical sensing, smart wearable and environmental monitoring are further summarized. Finally, the future development trend of cellulose hydrogels is briefly introduced and the future development of cellulose hydrogel sensing materials is envisioned. [ABSTRACT FROM AUTHOR]

In a quest to find eco-friendly materials from renewable resources, researchers have focused on cellulose materials, which is the primary reinforcing component of plant cell walls. Nanocellulose is at the forefront of research due to its wide range of sources, biocompatibility, large surface area and tunable surface chemistry. It has gained considerable attention in various industries as a nano-reinforcement for polymer matrices due to its hierarchical structure (medical and healthcare, oil and gas, packaging, paper, board, composites, printed and flexible electronics, 3D printing, aerogels). In this paper, we have reviewed the recent advances in nanocellulose production, physical properties, structural characterization, surface modification strategies, pretreatment methods, applications, limitations and future directions. This review emphasizes the quantification of nanocellulose extraction and applications of the most prevalent areas of nanocellulose research. In view of its increasing and broader applications, the demand for nanocellulose is expected to increase in the future. [ABSTRACT FROM AUTHOR]

Flexible sensors play an important role in the field of smart devices. However, most flexible sensors suffer from poor sensing signal stability and monofunction. In this study, a multifunctional film (named PM) with dual conductive network structure was fabricated by nanocellulose crystal dispersed with silver nanoparticles and carbon nanotube. The PM film exhibited excellent conductivity (24.6 S/m) along with antimicrobial effects against Staphylococcus aureus and Escherichia coli. Furthermore, the PM sensor showed excellent electrothermal performance, reaching 133.1 °C within 50 s at 12 V, and an excellent temperature coefficient of resistance (TCR = −0.65 % °C−1) over a temperature range of 36–124 °C. More importantly, the PM sensor demonstrated a high strain sensitivity (GF = 1.66) and durability (320 cycles), capable of detecting minute human body movements at a strain as low as 1 %. Additionally, the PM sensor maintained a stable sensing performance even after 30 d of exposure to air. Therefore, the multifunctional integration of the PM sensor shows great potential for application in the field of flexible electronics. [Display omitted] • Okra polysaccharide in situ reduction of silver nanoparticles (AgNPs) • Nanocrystalline cellulose dispersed nanoparticles • AgNPs and carbon nanotubes to construct dual conducting network film • This film exhibits excellent multifunctional sensing properties. [ABSTRACT FROM AUTHOR]

Soft ionic conductors are widely used in flexible electronics. However, the simultaneous enhancement of their mechanical properties and ionic conductivity remains challenging. This paper reports the successful development of a strong and tough cellulose-based ionic conductor with exceptional mechanical properties and high ionic conductivity by in situ dissolution and reorganization of the fiber matrix of filter paper to create a multiscale structure. The resulting ionic conductor exhibits a fracture strength of 14.13 MPa and a fracture energy of up to 2.84 MJ/m3, exceeding most reported ionic conductors. It also exhibits an impressive ionic conductivity of up to 76.3 mS/cm. Results of experiments on its use in a flexible quasi-solid-state zinc-hybrid supercapacitor show its remarkable features, such as a high capacity of 218 mAh/g, an energy density of 217 Wh/kg, and a power density of 17,520 W/kg. Furthermore, it exhibits excellent temperature resistance, working effectively even at −60 °C. In addition, by incorporating kirigami structures, we fabricated a strain sensor with the cellulose-based ionic conductor with a high gauge factor, as well as a piezoresistive sensor for handwriting recognition and a capacitance pressure sensor for force mapping with wide range and sensitivity. This study opens up new possibilities for fabricating flexible electronics with superior performance using sustainable and renewable resources. [Display omitted] [ABSTRACT FROM AUTHOR]

The advent of wearable sensing platforms capable of continuously monitoring physiological parameters indicative of health status have resulted in a paradigm shift for clinical medicine. The accessibility and adaptability of such portable, unobtrusive devices enables proactive, personalized care based on real-time physiological insights. While wearable sensing platforms exhibit powerful capabilities for continuously monitoring physiological parameters, device fabrication often requires specialized facilities and technical expertise, restricting deployment opportunities and innovation potential. The recent emergence of rapid prototyping approaches to sensor fabrication, such as laser-induced graphene (LIG), provides a pathway for circumventing these barriers through low-cost, scalable fabrication. However, inherent limitations in laser processing restrict the spatial resolution of LIG-based flexible electronic devices to the minimum laser spot size. For a CO 2 laser–a commonly reported laser for device production–this corresponds to a feature size of ∼120 μm. Here, we demonstrate a facile, low-cost stencil-masking technique to reduce the minimum resolvable feature size of a LIG-based device from 120 ± 20 μm to 45 ± 3 μm when fabricated by CO 2 laser. Characterization of device performance reveals this stencil-masked LIG (s-LIG) method yields a concomitant improvement in electrical properties, which we hypothesize is the result of changes in macrostructure of the patterned LIG. We showcase the performance of this fabrication method via production of common sensors including temperature and multi-electrode electrochemical sensors. We fabricate fine-line microarray electrodes not typically achievable via native CO 2 laser processing, demonstrating the potential of the expanded design capabilities. Comparing microarray sensors made with and without the stencil to traditional macro LIG electrodes reveals the s-LIG sensors have significantly reduced capacitance for similar electroactive surface areas. Beyond improving sensor performance, the increased resolution enabled by this metal stencil technique expands capabilities for scalable fabrication of high-performance wearable sensors in low-resource settings without reliance on traditional fabrication pathways. • Introduced stencil-masked patterning process for Laser-Induced Graphene (LIG) sensors. • Reduced LIG sensor feature size from 120 μm to 45 μm using CO2 laser. • Process yields LIG sensors with enhanced electrochemical performance. • Expanded design possibilities for wearable LIG-based sensors. • Process offers cost-effective, scalable technique for democratizing sensor innovation. [ABSTRACT FROM AUTHOR]

The main objective of this work is to propose a partial recoverable cohesive interface model, coupled with a bi-potential contact algorithm, to simulate the phenomenon of adhesion recoverability degradation under cyclic bonding–debonding between hyperelastic bodies. For this end, the proposed adhesion recoverability degradation model is constructed by defining the recovery of interface damage during the rebonding when two bodies come into contact, and a degradation factor related to the number of bonding–debonding cycles is introduced into the fully recoverable adhesion model to reduce energy dissipation after multiple cycles. Recoverability degradation includes adhesive stiffness and strength degradation, which is physically described as parallel, series and mixed arrays of adhesive bonds. Then, a finite element framework coupling the adhesion recoverability degradation model and the bi-potential contact algorithm is proposed, with Mooney–Rivlin hyperelastic material used to describe the soft matters. This framework is implemented in an in-house finite element code, with numerical examples demonstrating the model's reliability. The proposed approach could be applied to investigate interfacial adhesion effects in fields such as flexible electronics and intelligent robotics. • An adhesion recoverability degradation model is developed. • Adhesive stiffness and strength degradation are physically described as parallel and series array of adhesive bonds. • Finite element framework for partial recoverable adhesive contact problems of hyperelastic solids is constructed. [ABSTRACT FROM AUTHOR]

The quest for organic materials with compliant mechanical properties has significantly increased in the past few years in materials science and engineering. Crystalline organic compounds are excellent candidates for exploring and developing those long-lasting properties in the solid state since their fine structural functionalization may provide them with unique flexible behaviors. This study describes the 1,4-bis(phenylethynyl)benzene butyl ester synthesized in four steps and whose crystal can display elastic and elasto-plastic responses upon action with an external stimulus. A detailed characterization by single crystal X-ray diffraction revealed a layered crystal array that results from π-π stacking interactions, C–H⋯O and C-H⋯π bonds. Complementarily, variable temperature solid-state 13C and 2H NMR studies were carried out to probe the motion of the different components of the molecule and explore their possible association with the mechanical features. The compiled evidence indicates that the central phenylenes and the butyl groups experience molecular motion at different timescales, which, combined with the crystal array, facilitate the observed elastic and elasto-plastic flexibility. The results presented here not only contribute to advancing our understanding of flexible behavior but also could inspire potential applications such as flexible electronics. [Display omitted] [ABSTRACT FROM AUTHOR]

• PBA and DMAA in ionogel offers abundant physical cross-linking. • Addition of [BMIM][TFSI] to ionogel provides environmental stability and adhesion. • The ionogel are prepared by a simple and convenient UV photoinitiation method. • Multifunctional ionogel are stretchable, electrically conductive, and self-healing. Conventional hydrogels integrated into sensor technologies face insufficient synergy between mechanical adaptability, conductive sensitivity, self-adhesion and self-healing. Therefore, we prepared an ionogel by photoinitiated polymerization using 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonimide) salt ([BMIM][TFSI]) as the dispersing medium and ethyl 2-[[(butylamino)carbonyl]oxo]acrylate (PBA) and N,N-dimethylacrylamide (DMAA) as the monomers, which possess high stretching, high electrical conductivity, self-healing adhesion and remain very soft in extreme environments while being able to be twisted at will. The rich chemical cross-linking and physical cross-linking in the ionogel endows it with excellent fracture strength and elongation at break at room temperature, while its deformation durability is very strong, tensile/release cycling 5000 times still shows stable resistance change, and it has a good self-repairing ability, and its repairing efficiency can reach more than 90 % after 12 h of repairing at 20 ℃. In addition, the addition of fluorinated ionic liquids resulted in excellent environmental stability, virtually unchanged quality for 21 days in an 80 °C oven as well as strong adhesion to different substrates. The ionogel designed in this work have promising applications in wearable devices and electronics. [ABSTRACT FROM AUTHOR]

Silver nanowire (AgNW) transparent conductive thin films possess high flexibility, high conductivity, high light transmittance and etc., demonstrating significant advantages in flexible electronics applications. However, in the service occasions, the coupled effect of corrosion and mechanical force easily makes the electrical conductivity of AgNW films deteriorate or even fail, which seriously affects the service reliability of AgNW films. In this work, scanning vibrating electrode technique was firstly used to confirm the existence of electrochemical corrosion on AgNW films. Furthermore, electrochemical measurements (including OCP, PDP and EIS) were carried out for researching the electrochemical corrosion process on AgNW films under different environmental factors and mechanical forces. Their surface morphologies and electrical conductivity were characterized and evaluated by the Scanning Electron Microscopy and square resistance tester respectively. Experimental results indicate that the corrosion-mechanics interaction effect aggravates the damage process of electrical conductivity of AgNW films. • Electrochemical corrosion reaction was firstly confirmed on AgNW films by SVET in a simulated sulfur-containing atmosphere. • After bending, the microstructure of AgNW is more easily broken and sensitive to corrosion. • Corrosion-mechanics interaction effect synergistically accelerates the deterioration process of conductivity of AgNW films. [ABSTRACT FROM AUTHOR]

Micro-supercapacitors (MSCs) have wide application prospects in microelectronic fields such as wearable electronics due to merits of stable performance, high safety and easy integration. However, the relatively low energy density of MSCs limits their practical application. In this context, phosphorus and fluorine co-doped laser-induced graphene (FP-LIG) microelectrodes were fabricated from fluorinated polyimide containing phosphoric acid by laser direct writing (LDW) method. The introduced phosphoric acid slows down the decomposition of –CF 3 during the LDW process, resulting in much more ordered and stable pores; meanwhile, phosphorus entered the graphene lattice to replace some carbon atoms, forming a C 3 PO structure, which not only stabilizes the interface between the electrode and the electrolyte and therefore achieves an enlarged working potential of 1.4 V, but also increases the wettability of the electrode. Using FP-3-LIG microelectrodes and PVA/H 2 SO 4 as the gel electrolyte, the assembled FP-3-MSC demonstrates significantly enhanced energy density, delivering an energy density of 10.40 μWh cm−2 (@0.09 mA cm−2), 2.7 times that of F-MSC and 346.7 times that of MSC. FP-3-MSC has excellent cyclic stability, displaying an areal capacitance retention rate of above 90 % after 10,000 long cycles. In addition, FP-3-MSC demonstrates excellent flexibility, indicating promising potential in the field of flexible wearable electronics. [Display omitted] • The phosphorus doping resulted in a more stable and ordered pore structure. • The formed C 3 PO structure increased the voltage window from 1.0 to 1.4 V. • The C 3 PO structure increased the wettability of FP-3-LIG. • FP-3-MSC exhibited significantly enhanced energy density (10.40 μWh cm-2). [ABSTRACT FROM AUTHOR]

Magnetostrictive materials are widely used in sensors, actuators and micro-nano electronics because of their excellent performance. However, traditional rigid magnetostrictive materials are difficult to adapt to the flexible and deformable structure of flexible electronic devices. In order to solve the deformation, sensing and control problems in the field of flexible electronics, a one-step new method of is proposed to deposit Fe 50 Co 50 fiber ribbons with reciprocated and loop structures on flexible substrate. Helmholtz coil is designed to test the magnetostrictive positive effect ability of Fe 50 Co 50 ribbon, and its magnetostrictive strain curve is analyzed. Furthermore, frequency domain characteristics of Fe 50 Co 50 ribbon are tested, and the influence of externally driving magnetic field on elastic layer materials and resonance output characteristics is analyzed. The experimental results show that Fe 50 Co 50 ribbon exhibits good low-frequency magnetic field characteristics. And free end displacement of Fe 50 Co 50 ribbon based on loop structure, under 12 mT alternating magnetic field and 134 mT bias magnetic field, reaches a peak-to-peak value of 870 μm for first-order resonance, and 320 μm for second-order resonance. This verifies that Fe 50 Co 50 ribbon possesses the expected properties that magnetostrictive materials should have, and innovatively breaks through the technical bottleneck of manufacturing flexible micro-nano magnetostrictive energy exchange components. [Display omitted] • Proposing a one-step fabrication method of flexible magnetostrictive fiber ribbon. • Fabricated Fe50Co50 fiber ribbon has great positive effect deformation ability. • Peak-to-peak displacement reaches 870 μm and 320 μm at 47.4 Hz and 72.4 Hz. • Fabrication method is cost-effective and more suitable for practical application. [ABSTRACT FROM AUTHOR]

Flexible substrates, essential for flexible electronics by providing support and flexibility while influencing sensor stability, still face challenges in achieving mechanical and thermal stability, particularly in large-scale production and cost control. Inspired by the nacre's "brick-and-mortar" hierarchical microstructure, this study introduces PPSN (paper/polydimethylsiloxane (PDMS)/Si₃N₄ nanoparticles), a novel flexible substrate that mimics the "brick-and-mortar" structure. PPSN, with its topological interlocking and assembly technique, provides excellent thermal and mechanical stability, including high-temperature resistance and stress dissipation. An optimized Si₃N₄ content of 1.0 wt% yields a peak elastic modulus of 1245.27 MPa while maintaining hydrophobicity, with a contact angle of 127.1° at 3.0 wt%. The substrate shows excellent fatigue durability, retaining its morphology after 10,000 bending cycles. Thermal analysis indicates a stable CTE below 20 ppm/°C up to 300°C, rising to 200 ppm/°C between 350 and 400°C. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) reveal minimal thermal decomposition with mass loss below 0.5 % from 25 to 300°C and under 3 % at 400°C. Additionally, electrodes were printed on the substrate using screen printing and ion beam deposition (IBD), demonstrating good material adhesion. A flexible temperature sensor was fabricated and exhibited good sensitivity and stability with a TCR of −0.262 % °C⁻¹. PPSN advances traditional materials with superior mechanical strength, thermal stability, and durability, offering significant scientific and practical value for flexible electronics and low-cost biomimetic processes. [Display omitted] • PPSN mimics nacre's structure, offering high thermal and mechanical stability. • Peak elastic modulus at 1.0 wt% Si₃N₄, with hydrophobicity and durability. • Stable CTE below 20 ppm/°C up to 300°C with minimal thermal mass loss. • Excellent performance in flexible sensors with a TCR of −0.262 % °C⁻¹. [ABSTRACT FROM AUTHOR]

Flexible electronics have attracted great interest because of their potential applications in healthcare monitoring and human-computer interaction. The performance of flexible electronics depends on the design of structure, materials, and mechanical responses. In this work, we explore the use of polyurethane (PU) sponge as the scaffold to form flexible piezoresistive pressure sensors with conductive networks made from conductive polymer PEDOT:PSS and MXene nanosheets. The sensitivity of the prepared pressure sensors reaches 0.2171 kPa−1 under mechanical pressure in a range of 1.8–6.15 kPa. The prepared pressure sensors are re-usable after washing. The applications of the prepared pressure sensors in the sensing of physiological behavior are demonstrated under the action of finger tapping, finger bending, vocal cord vibration, swallowing, and pulsing of radial artery. The prepared pressure sensors have great prospects for applications in human-machine interaction and physiological diagnosis. [Display omitted] • Use polyurethane sponge as the scaffold to form flexible pressure sensors. • Pressure sensors have a sensitivity of 0.2171 kPa−1 under 1.8–6.15 kPa. • Pressure sensors are re-usable after washing in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Buckling instability of a stiff thin film embedded between two compliant substrates with finite thickness is studied. • The analytical model, considering a complete form of interfacial shear stress, shows higher accuracy than previous models. • Phase diagrams to distinguish global buckling and local wrinkling are constructed through energy analysis. • Effects of finite thicknesses and material properties on the critical condition for local wrinkling are revealed. Capturing the buckling instability mechanics of multi-layered film/substrate structures is essential for providing theoretical guidelines for designing flexible electronics (e.g., stretchable interconnects and strain-limiting structures) and understanding the morphogenesis in biology and geology. Previous buckling models of tri-layer substrate/film/substrate structures usually assumed infinite substrate thickness and incomplete forms of interfacial shear stress, failing to distinguish between local wrinkling and global buckling. In this work, we extend our previous model (Yuan et al., 2023) by accounting for both finite substrate thickness and a complete form of interfacial shear stress, without assuming uniform membrane strain in the film, to study the buckling instability of tri-layer structures. The local wrinkling versus global buckling is distinguished through energy analysis, yielding phase diagrams for a wide range of geometric parameters and material properties. The effects of finite substrate thickness and moduli on the critical compressive strain and wavelength for the onset of local wrinkling are thoroughly investigated. The high accuracy of current model is demonstrated by the excellent agreement between analytical predictions and finite element analysis. This study provides new insights into the stability analysis of substrate/film/substrate systems, and will aid in the design of flexible electronics. [ABSTRACT FROM AUTHOR]

Stretchable displays are essential for the upcoming era of flexible electronics as they are the foundation of interactive human–machine interface. To date, alternating current electroluminescent (ACEL) devices are regarded as one of the most practicable routes for stretchable displays but their colors are very limited for the demand of full-color displays. Herein, we developed an ACEL device with Janus and full color through photoluminescent electrodes. In the front of the devices, multiple colors are achieved, Red, Blue, Green, and Yellow, covering a 66 % National Television System Committee color gamut. In the back, mixed lights of White, Purple, and Cyan color are obtained, enabling devices with Janus colors. The brightness enhancement of highly desirable white light achieves 4.4-fold, which is also one of the best performances. Our strategy exploits the indispensable electrode for ACEL and avoids structural changes, endowing the devices with a much better stretchability and brightness as compared to traditional methods. Moreover, our strategy is a general method that is applicable to different stretchable ACEL devices. A wearable device of 8*8 pixels is assembled and can dynamically display information from smart phones through Bluetooth in real time, laying a considerable advancement towards stretchable displays with full color. • Stretchable display of full-color is developed by photoluminescent electrodes. • The display has Janus colors and the brightness could be enhanced to 4.4-fold. • Red, Yellow and Green in the front while White, Purple and Cyan in the back. • The strategy avoids structures change of the stretchable ACEL display. • Colorful display can dynamically display the information from Bluetooth. [ABSTRACT FROM AUTHOR]

Chiral metamaterials were a typical metamaterial configuration, which had broad application prospects in vibration isolation, energy absorption and other fields. Although 4D-printed chiral metamaterials have been investigated by introducing stimulus-responsive materials to achieve programmable properties of metamaterials, chiral metamaterials are mostly fabricated by single materials, which limits the adjustable domains of the mechanical properties and the design freedom of metamaterials. In this work, inspired by the configuration of collagen fibers of biological tissues, the bio-inspired chiral metamaterials with wave ligaments were developed. The bi-phase (TPE@PLA-SMP) composite chiral metamaterials were fabricated by combining active phase (shape memory polylactic acid, PLA-SMP) with passive phase (thermoplastic elastomer, TPE). The influences of geometric parameters, ligament gradient forms, and TPE distribution modes on the mechanical properties of the developed metamaterials were characterized. When the TPE was distributed at 0° and 45°, the deformation of the mechanical metamaterials occurred mainly in the TPE cells, resulting in the J -shaped displacement-force curve. The programmable and reconfigurable properties of the metamaterials (including configuration, and energy absorption performance) under thermal stimulation were demonstrated. The specific energy absorption (SEA) of the metamaterial 2 θ = π /2 was realized to transform between 0.92 kJ/kg and 0.38 kJ/kg by shape memory programming. Flexible sensors based on TPE@PLA-SMP composite metamaterials were developed by filling CNC-CNT@PVA composite hydrogels (minimum resistivity 8.1 Ω m), which enabled stable output of electrical signals under repeated loads. A motion state monitor was developed and realized to monitor the wearer's movement such as running, demonstrating its potential application prospects in fields such as flexible electronics. [ABSTRACT FROM AUTHOR]

With the continuous development of electronic products, polymers with EM shielding have received widespread attention. In this study, Fe 3 O 4 @RGO was prepared by the hydrothermal synthesis method, which solved the problems of Fe 3 O 4 precipitation and RGO stacking. Using it as a precursor, Fe 3 O 4 @RGO/PAM conductive hydrogel was prepared. The research shows that the conductivity of this hydrogel reaches 16.2 S/m at a thickness of 0.3 cm, and the maximum EMI SE is 27.1 dB. Among them, RGO can form a conductive framework, and Fe 3 O 4 can optimize the impedance matching and provide additional magnetic loss. The combined effect of the two makes the hydrogel have excellent EMI SE. In addition, PAM-based hydrogels have good thermal stability, crystallinity, water content, and mechanical properties. • Prepared Fe 3 O 4 @RGO/PAM hydrogel with EMI SE through a simple method. • It has excellent mechanical properties, high conductivity, and good thermal stability. • The hydrogel shows good thermal stability and high swelling rate. • Has potential in flexible electronics and biomedicine applications. [ABSTRACT FROM AUTHOR]

Biodegradable aliphatic polyesters are intensively applied in food packaging, regenerative medicine, tissue engineering, water purification and flexible electronics. However, the performance of these polymers is largely hindered by their inherent hydrophobicity. Here we report a facile method for producing hydrophilic fibers based on biodegradable aliphatic polyesters. Specifically, poly (lactide caprolactone) (PLCL) was dissolved in solvent systems containing trifluoroacetic acid (TFA) for electrospinning. Increasing TFA proportion or dissolving time successfully decreased the water contact angle (WCA) of PLCL fibrous membranes from 124° to 67°. The mechanism of wettability alteration was elucidated and ascribed to the generation of hydrophilic carboxyl acid and hydroxyl groups vis the acid hydrolysis reaction that cleaved PLCL chains. The exponential relationship between molecular weight and WCA confirmed the mechanism, pointing out an in-situ way for accurately controlling the wettability of PLCL. The efficacy of using hydrophilic PLCL membranes in biomedical engineering and environmental protection was preliminarily verified. Janus membranes with unidirectional water transfer were also fabricated. The versatility of our method was further proven by the switchable wettability of fibers spun from various biodegradable polyesters, including polylactide, polycaprolactone and poly (lactic-glycolic acid). We anticipate this work will broaden the application fields of biodegradable aliphatic polyesters. [Display omitted] • Hydrophobic membranes based on biodegradable aliphatic polyester are switched to hydrophilic via acid hydrolysis. • The mechanism of wettability transformation is elucidated through studying the molecular structure of the polymer. • Membranes with switchable wettability are preferred in biomedical engineering, oil/water separation and liquid transfer. • Versatility of our method is proved in a variety of biodegradable aliphatic polyesters. [ABSTRACT FROM AUTHOR]

Tactile and pain perception are essential for biological skin to interact with the external environment. This complex interplay of sensations allows for the detection of potential threats and appropriate responses to stimuli. However, the challenge is to enable flexible electronics to respond to mechanical stimuli such as biological skin, and researchers have not clearly reported the successful integration of somatic mechanical perception and sensation management functions into neuro-like electronics. In this work, an afferent nerve-like device with a pressure sensor and a perception management module is proposed. The pressure sensor comprises two conductive fabric layers and an ionic hydrogel, forming a capacitor structure that emulates the swift transition from tactile to pain perception under mechanical stimulation. Drawing inspiration from the neuronal "gate control" mechanism, the sensation management module adjusts signals in response to rubbing, accelerating the discharge process and reducing the perception duration, thereby replicating the inhibitory effect of biological neurons on pain following tactile interference. This integrated device, encompassing somatic mechanical perception and sensation management, holds promise for applications in soft robotics, prosthetics, and human-machine interaction. [ABSTRACT FROM AUTHOR]