Mechanically Robust Research Articles

Self-healable, recyclable, and mechanically robust vitrimer composite for high-performance triboelectric nanogenerators and self-powered wireless electronics

With growing concerns about sustainability, there has been significant research interest in fabricating triboelectric nanogenerators (TENGs) from materials capable of self-repair. Here, we presented a novel polyimine/graphite polypropylene (PI/GP) vitrimer composite as a tribo-positive material for harvesting biomechanical energy. The PI/GP exhibited mechanical robustness, self-healing properties after damage, and recyclability through physical or chemical methods. The GP provided a high dielectric constant, charge transport paths, and desirable surface roughness, resulting in an outstanding TENG performance at an optimized addition level of 30 wt% in the composite (PI/GP30). Under a force of 15 N and a frequency of 6 Hz, the PI/GP30 TENG generated a power density of 2571 mW/m². Moreover, a PI/GP30 TENG device with an area of 49 cm2 was able to generate a remarkable output voltage of nearly 1325 V, at a frequency of 6 Hz and under a vertical force of 15 N. Additionally, the PI/GP30 TENG device produced a peak-to-peak voltage of 1250 V, and an outstanding current of around 2 mA by hand tapping with a force of 35–40 N. The PI/GP30 TENG was utilized for real-life applications, including a triboelectric watchband for a self-powered watch, and wireless data transmission. Furthermore, the PI/GP30 TENG demonstrated excellent self-healing and recyclability, and these properties were examined in a mousepad power generator. This study highlights the excellent promise of PI/GP vitrimer composite for fabricating high-performance, mechanically robust, self-healable, and recyclable TENGs, enabling their applications in green biomechanical power generators and wearable and wireless communication devices.

Mechanically robust and highly conductive bacterial cellulose hydrogels through synergy of directional freeze–thawing and salting-out for wearable sensors

It is urgent to develop high-performance conductive hydrogels that simultaneously exhibit high biocompatibility, mechanical robustness, exceptional conductivity and frost resistance to fulfil the requirements of wearable flexible sensors. Herein, we present a simple and integrated approach for designing iso/anisotropic bacterial cellulose (BC) hydrogels by immersing the as-prepared polyvinyl alcohol (PVA)–BC–Borax hydrogels in saturated NaCl solutions using a salting-out effect to assist the non–/directional freeze–thawing strategy. Benefitting from the synergistic strengthening of molecular interactions, including hydrogen, coordination, and boron ester bonds, as well as the enhanced PVA and BC crystallinity resulting from the salting-out effect, the tensile strength (0.8–3.2 MPa) and high ionic conductivity (61.5–136.2 mS/cm) of isotropic hydrogels (PVA–BC–Borax/NaCl) can be well tuned by adjusting the feeding mass fractions of PVA, borax and BC. The optimised hydrogel, PVA7.5%–BC0.45%–Borax0.375%/NaCl, demonstrated remarkable mechanical properties (3.2 MPa, 295.1 %), ionic conductivity (72.6 mS/cm) and good anti-freezing properties (–40.8 °C), maintaining excellent conductivity (61.8 mS/cm) even at –20 °C due to the introduction of NaCl. When subjected to directional freeze–thawing cycles, the D(Directional)-PVA7.5%–BC0.45%–Borax0.375%/NaCl hydrogel, with its organised layers and larger pore–sized structures, exhibited higher breaking elongation (609.2 %) and ionic conductivity (81.6 mS/cm) than its isotropic counterpart (295.1 %, 72.6 mS/cm). The D-PVA7.5%–BC0.45%–Borax0.375%/NaCl hydrogel was successfully used as a strain sensor for detecting a variety of human movements, showing excellent responsiveness to external stimuli, thereby demonstrating its potential applications in human–machine interaction, flexible sensing and bioelectronics.

Uncovering the Relationship between Metal Elements and Mechanical Stability for Metal-Organic Frameworks.

Assessing the mechanical robustness of metal-organic frameworks (MOFs) is crucial to enhance their applicability in various fields. Although considerable research has been conducted on the relationship between the mechanical properties of MOFs and their structural features (such as pore size, surface area, and topology), the insufficient exploration of metal elements has prevented researchers from fully understanding their mechanical behavior. To plug this knowledge gap, we constructed a database of mechanical properties for 20,342 MOFs included in the QMOF database using molecular simulations to investigate the impact of metal elements on mechanical stability. Through Shapley additive explanations (SHAP) analysis, we found that Co and Ln could enhance the structural stability of MOFs. We validated these findings using newly generated hypothetical MOFs. Notably, we adopted an interpretable machine learning technique to analyze the contribution of remarkably diverse metal elements in the 20,342 MOFs to the mechanical properties of each MOF. We anticipate that this research will serve as a valuable tool for future studies on identifying mechanically robust MOFs suitable for various industrial applications.

Ultrahigh Responsivity and Robust Semiconducting Fiber Enabled by Molecular Soldering-Governed Defect Engineering for Smart Textile Optoelectronics.

Semiconducting fibers (SCFs) are of significant interest to design next-generation wearable and comfortable optoelectronics that seamlessly integrate with textiles. However, the practical applications of current SCFs are always limited by poor optoelectronic performance and low mechanical robustness caused by uncontrollable multiscale structural defects. Herein, a versatile in situ molecular soldering-governed defect engineering strategy is proposed to construct ultrahigh responsivity and robust wet-spun MoS2 SCFs, by using a π-conjugated dithiolated molecule to simultaneously patch microscale sulfur vacancies within MoS2 nanosheets, diminish mesoscale interlayer voids/wrinkles, promote macroscale orientation, build long-range photoelectron percolation bridges, and provide n-doping effect. The derived MoS2 SCFs exhibit over two orders of magnitude higher responsivity (144.3 A W-1) than previously reported fiber photodetectors, 37.3-fold faster photoresponse speed (52ms) than pristine counterpart, and remarkable bending robustness (retain 94.2% of the initial photocurrent after 50000 bending-flattening cycles). Such superior robustness and photodetection capacity of MoS2 SCFs further enable large-scale weaving of reliable smart textile optoelectronic systems, such as direction-identifiable wireless light alarming system, modularized mechano-optical communication system, and indoor light-controlled IoT system. This work offers a universal strategy for the scalable production of mechanically robust and high-performance SCFs, opening up exciting possibilities for large-scale integration of wearable optoelectronics.

Sustainable Plastics with High Performance and Convenient Processibility.

Designing and making sustainable plastics is especially urgent to reduce their ecological and environmental impacts. However, it remains challenging to construct plastics with simultaneous high sustainability and outstanding comprehensive performance. Here, a composite strategy of in situ polymerizing a petroleum-based monomer with the presence of an industrialized bio-derived polymer in a quasi-solvent-free system is introduced, affording the plastic with excellent mechanical robustness, impressive thermal and solvent stability, as well as low energy, consumes during production, processing, and recycling. Particularly, the plastic can be easily processed into diverse shapes through 3D printing, injection molding, etc. during polymerization and further reprocessed into other complex structures via eco-friendly hydrosetting. In addition, the plastic is mechanically robust with Young's modulus of up to 3.7GPa and tensile breaking strength of up to 150.2MPa, superior to many commercially available plastics and other sustainable plastics. It is revealed that hierarchical hydrogen bonds in plastic predominate the well-balanced sustainability and performance. This work provides a new path for fabricating high-performance sustainable plastic toward practical applications, contributing to the circular economy.

Eco-friendly development of intrinsically antibacterial and mechanically robust self-healing hydrogels using alginate and oval proteins: Advancing periodontitis treatment

A novel approach for fabricating self-healing, intrinsically antibacterial hydrogels for potential periodontitis treatment is presented in this study. Self-healable hydrogels are promising substitutes for brittle hydrogels due to their excellent durability and stability. Drug-loaded regenerative hydrogels have shown good outcomes but face challenges, specifically in managing the development of drug resistance. The hydrogels were prepared by incorporating bioactive oval proteins and hydroxyapatite into polyvinyl alcohol using a simple synthesis method with eco-friendly crosslinkers (oxidized alginate, borax, and divalent metal salts). The synthesized hydrogels exhibited excellent self-healing properties, mechanical robustness, and malleability. Furthermore, characterization techniques confirmed successful crosslinking and interactions within the network. The hydrogels demonstrated significant water absorption, tunable degradation, and potent antibacterial activity against E. coli, S. aureus and P. gingivalis. In vitro studies confirmed good cytocompatibility with epithelial and fibroblasts cells. Wound healing assays further supported the potential of these hydrogels for tissue regeneration applications. This approach offers a promising alternative to traditional drug-loaded hydrogels, overcoming limitations of cost and potential for resistance.

Bioprinting of anisotropic functional corneal stroma using mechanically robust multi-material bioink based on decellularized cornea matrix

Corneal scarring is a common cause of blindness, affecting millions globally each year. A huge gap between the demand and supply of donor tissue currently limits corneal transplantation, the only definitive therapy for patients with corneal scarring. To overcome this challenge, researchers have harnessed the efficacy of 3D bioprinting to fabricate artificial corneal stromal constructs. With all the different bioinks available, the decellularized corneal matrix-based bioprinted construct can fulfill the required biological functionality but is limited by the lack of mechanical stiffness. Additionally, from a biophysical standpoint, it is necessary for an ideal corneal substitute to mimic the anisotropy of the cornea from the central optic zone to the surrounding periphery. In this study, we enhanced the mechanical robustness of decellularized cornea matrix (DCM) hydrogel by blending it with another natural polymer, sonicated silk fibroin solution in a defined ratio. Although hybrid hydrogel has an increased complex modulus than DCM hydrogel, it has a lower in vitro degradation rate and increased opaqueness due to the presence of crystalline beta-sheet conformation within the hydrogel. Therefore, we used this multi-material bioink-based approach to fabricate a corneal stromal equivalent where the outer peripheral corneal rim was printed with a mechanically robust polymeric blend of DCM and sonicated silk fibroin and the central optic zone was printed with only DCM. The bioprinted corneal stroma thus maintained its structural integrity and did not break when lifted with forceps. The two different bioinks were encapsulated with human limbus-derived mesenchymal stem cells (hLMSC) individually and 3D bioprinted in different patterns (concentric and parallel) to attain a native-like structure in terms of architecture and transparency. Thus, the bilayer cornea constructs maintained high cell viability and expressed keratocyte core proteins indicating optimal functionality. This approach helped to gain insight into bioprinting corneas with heterogeneous mechanical property without disturbing the structural clarity of the central optic zone.

Multifunctional composite electrolytes for mechanically-robust and high energy density carbon fiber structural batteries

Mechanically robust electrolytes with high ionic conductivity play an essential role in carbon fiber (CF) structural batteries that simultaneously store energy and bear mechanical loads. However, multifunctional composite electrolytes are rarely developed, especially for air-stable and safe structural Zn-ion batteries. Herein, a composite electrolyte GF-SPE is designed and fabricated by integrating ionic conductive poly(ethylene glycol) diacrylate (PEGDA)-based solid-state polymer electrolyte (SPE) matrix and glass fiber fabric (GF) reinforcement, which simultaneously exhibits mechanical robustness and high ionic conductivity, facilitating homogeneous Zn electrodeposition without obvious side reaction, such as dendrite growth, corrosion et al. Therefore, the symmetric cells Zn//GF-SPE//Zn cell can cycle stably for more than 800 h at 1 mA cm−2. The carbon fiber structural battery fabricated with composite structural electrolyte GF-SPE delivers a high energy density of 19.35 Wh kg−1 based on the total mass of the whole device and cycling stability over 1,000 cycles in extreme environments. Furthermore, the high capacity of structural Zn-ions batteries can be maintained when they withstand flexural stress of over 120 MPa. The in-situ mechanical-electrochemical testing further confirms the priority of structural Zn-ion batteries.

Review on Artificial Interphases for Lithium Metal Anodes: From a Mechanical Perspective

AbstractLithium (Li) metal is a promising candidate for next‐generation high‐energy‐density rechargeable batteries. However, the solid electrolyte interphase (SEI) inevitably suffers from mechanical fracture owing to the large morphological change during Li cycling, leading to the uncontrollable growth of Li dendrites, low Coulombic efficiency, and short cycle life. The fabrication of an artificial interphase is an effective strategy for improving the performances of Li metal anodes. The ideal artificial interphase should provide sufficient mechanical robustness to suppress dendritic Li growth and accommodate large volume changes during Li deposition‐dissolution cycles. In this review, we focus on the fabrication of mechanically robust artificial interphases for stabilizing Li‐metal anodes, including the underlying mechanism of SEI fracture, quantitative requirements for mechanical properties, measurements of mechanical properties, and recent progress in the fabrication of mechanically stable artificial interphases.

A novel strategy for design of mechanically robust antifouling coatings via bifunctional domain engineering

The issue of biofouling on marine structures carries significant economic and ecological implications, necessitating the development of effective and durable antifouling coatings. Traditional organic antifouling coatings often struggle with mechanical robustness in harsh marine environments, making them fragile and highly susceptible to abrasion. To address these challenges, we propose a novel “bifunctional domain engineering” strategy for designing robust antifouling coatings that combines excellent mechanical strength of a Fe-based amorphous layer and high antifouling efficacy of an incorporated organics. The hard domains consist of Fe-based amorphous micro humps, providing a sturdy framework that enhances the coating's mechanical durability. In contrast, the soft domains comprise epoxy resin infused with Cu2O and 4,5-Dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), offering a dual-action antifouling function via controllable antifouling agent release. Evaluation of antifouling performance by lab tests against Pseudomonas aeruginosa, Staphylococcus aureus, and Chlorella algae and practical marine field tests (for 150 days) demonstrates significant reductions in bacterial and algal adhesion (nearly 100 % resistance) with the bifunctional domain engineered coating (referred to as HSR coating), compared to pure amorphous coating. Mechanical durability tests, including abrasion and erosion experiments, underscore the HSR coating's excellent wear resistance. Importantly, the HSR coating maintains its outstanding antifouling properties even after 1000 abrasion cycles, highlighting its potential for long-term marine applications in harsh conditions. This study lays the groundwork for design of robust antifouling coatings capable of withstanding the harsh operating environments while effectively combating biofouling.

Development of a mechanically robust silicon-based cross-linking polymer for the sustainable marine antifouling coatings

Silicone-based fouling release coatings (FRCs) have shown great promise as an environmentally friendly antifouling technology, while inferior mechanical properties and insufficient substrate adhesion have hindered their further application. We focused on enhancing the mechanical robustness of silicone-based coating through the synergistic effects of hydrogen bonding, π-π aromatic interaction and covalent bonding. The resulting silicone-based coating displayed a low surface energy of 23 mJ/m2 and improved mechanical strength and substrate adhesion, offering values up to 6.4 MPa (9.1 times higher) and 2.87 MPa (25.7 times higher), respectively. Additionally, the modified coating demonstrated a tear strength of 9.8 kN/m and mass loss only about 30 mg after enduring 10,000 wear cycles. Alkoxysilane-functionalized polyethylene glycol and quaternary ammonium salt were grafted into the cross-linking structure to make them anchored to the networks and migrated to the surface layer in seawater without releasing. The coating provided 99.1% antibacterial efficiency and effective antidiatom performance (≤ 11.2 cell/mm2). After a 12-month marine field test, the developed film showed only 20% micro bio-fouling compared to 100% fouling coverage on the PDMS surface. By combining improved mechanical properties with antifouling characteristics, this new multifunctional silicone-based FRC exhibits tremendous potential for sustainable marine antifouling coating application.

Advances in Stretchable Organic Photovoltaics: Flexible Transparent Electrodes and Deformable Active Layer Design.

Stretchable organic photovoltaics (OPVs) have attracted significant attention as promising power sources for wearable electronic systems owing to their superior robustness under repetitive tensile strains and their good compatibility. However, reconciling a high power-conversion efficiency and a reasonable flexibility is a tremendous challenge. In addition, the development of stretchable OPVs must be accelerated to satisfy the increasing requirements of niche markets for mechanical robustness. Stretchable OPV devices can be classified as either structurally or intrinsically stretchable. This work reviews recent advances in stretchable OPVs, including the design of mechanically robust transparent electrodes, photovoltaic materials, and devices. Initially, an overview of the characteristics and recent research progress in the areas of structurally and intrinsically stretchable OPVs is provided. Subsequently, research into flexible and stretchable transparent electrodes that directly affect the performances of stretchable OPVs is summarized and analyzed. Overall, this review aims to provide an in-depth understanding of the intrinsic properties of highly efficient and deformable active materials, while also emphasizing advanced strategies for simultaneously improving the photovoltaic performance and mechanical flexibility of the active layer, including material design, multi-component settings, and structural optimization.

A mechanically robust and facile shape morphing using tensile-induced buckling.

Inspired by the adaptive mechanisms observed in biological organisms, shape-morphing soft structures have emerged as promising platforms for many applications. In this study, we present a shape-morphing strategy to overcome existing limitations of the intricate fabrication process and the lack of mechanical robustness against mechanical perturbations. Our method uses tensile-induced buckling, achieved by attaching restraining strips to a stretchable substrate. When the substrate is stretched, the stiffness mismatch between the restraining strips and the substrate, and the Poisson's effect on the substrate cause the restraining strips to buckle, thereby transforming initially flat shapes into intricate three-dimensional (3D) configurations. Guided by an inverse design method, we demonstrate the capability to achieve complicated and diverse 3D shapes. Leveraging shape morphing, we further develop soft grippers exhibiting outstanding universality, high grasping efficiencies, and exceptional durability. Our proposed shape-morphing strategy is scalable and material-independent, holding notable potential for applications in soft robotics, haptics, and biomedical devices.

Mechanically robust, stretchable and environmentally adaptable organohydrogels with cross-linked fibrous structure for sensory artificial skins

Hydrogels are promising materials for fabricating sensory artificial skins (SASs), but their mechanical properties and environment adaptability are often limited, leading to restricted performances of SASs. In this work, mechanically robust, stretchable and environment adaptable organohydrogels with cross-linked fibrous structure are designed and constructed. The organohydrogels are prepared by introducing doped polyaniline (PANI) into cross-linked fibrous mats of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA). Cross-linked PAA-PVA mat works as skeleton to account for the mechanical robustness while PANI serves as the conductive component to achieve mechanosensing functionality. Due to the unique structure, the resultant organohydrogels, being denoted as PAA-PVA/PANI organohydrogels, exhibit high tensile strength (5.06 MPa), stretchability, fatigue resistance and excellent environment adaptability (anti-freezing, anti-drying and swelling resistance). SASs of such organohydrogels have achieved a gauge factor of 1.81, a sensing range of 0–70 %, a response time of 0.28 s and a reversible sensing in more than 2,000 cycles. In addition, SASs are further attempted in monitoring diverse human motions and physiological activities, such as joint bending, muscle motion and pulse. Overall, this work has provided promising soft materials for future SASs that work properly under complicated environmental conditions.

Biomimetic Mechanically Robust Chiroptical Hydrogel Enabled by Hierarchical Bouligand Structure Engineering.

Natural bouligand structures enable crustacean exoskeletons and fruits to strike a combination of exceptional mechanical robustness and brilliant chiroptical properties owing to multiscale structural hierarchy. However, integrating such a high strength-stiffness-toughness combination and photonic functionalities into synthetic hydrogels still remains a grand challenge. In this work, we report a simple yet general biomimetic strategy to construct an ultrarobust chiroptical hydrogel by closely mimicking the natural bouligand structure at multilength scale. The hierarchical structural engineering of long-range ordered cellulose nanocrystals' bouligand structure, well-defined poly(vinyl alcohol) nanocrystalline domains, and dynamic interfacial interaction synergistically contributes to the integration of high strength (23.3 MPa), superior modulus (264 MPa), and high toughness (54.7 MJ m-3), as well as extraordinary impact resistance, which far exceed their natural counterparts and synthetic photonic hydrogels. More importantly, seamless chiroptical and solvent-responsive patterns with high resolution can also be scalably integrated into the hydrogel by localized manipulation of the photonic band, while maintaining good ionic conductivity. Such exceptional mechanical-photonic combination holds tremendous potential for applications in wearable sensors, encryption, displays, and soft robotics.

Supramolecularly Connected Armor-like Nanostructure Enables Mechanically Robust Radiative Cooling Materials.

Passive daytime radiative cooling (PDRC) is a promising practice to realize sustainable thermal management with no energy and resources consumption. However, there remains a challenge of simultaneously integrating desired solar reflectivity, environmental durability, and mechanical robustness for polymeric composites with nanophotonic structures. Herein, inspired by a classical armor shell of a pangolin, we adopt a generic design strategy that harnesses supramolecular bonds between the TiO2-decorated mica microplates and cellulose nanofibers to collectively produce strong interfacial interactions for fabricating interlayer nanostructured PDRC materials. Owing to the strong light scattering excited by hierarchical nanophotonic structures, the bioinspired film demonstrates a desired reflectivity (92%) and emissivity (91%) and an excellent temperature drop of 10 °C under direct sunlight. Notably, the film guarantees high strength (41.7 MPa), toughness (10.4 MJ m-3), and excellent environmental durability. This strategy provides possibilities in designing polymeric PDRC materials, further establishing a blueprint for other functional applications like soft robots, wearable devices, etc.

Encapsulation of flexible transparent electrodes based on indium zinc tin oxide with highly transparent and mechanically robust polymer dielectrics

This study was aimed at comprehensively investigating the utility of polymethyl methacrylate (PMMA) and CYTOP as encapsulation layers for flexible transparent electrodes composed of indium zinc tin oxide (IZTO). Optical modeling and experimental techniques were combined to assess the viability of PMMA and CYTOP as encapsulation materials. Optical modeling suggested that PMMA and CYTOP are well-suited for IZTO encapsulation. Subsequent experiment confirmed that the transmittance values of IZTO-films remained unaffected when encapsulated with PMMA and CYTOP. To examine the influence of encapsulation on mechanical resilience, all film, including untreated IZTO and IZTO treated with PMMA/CYTOP, were subjected to 20,000 bending cycles. The mechanical stability and optical properties of the IZTO film were considerably enhanced when encapsulated with these insulating materials. The improvement in transmittance was attributable to the lower refractive index of PMMA and CYTOP. Furthermore, scanning electron microscopy images demonstrated that the remarkable flexibility of PMMA and CYTOP effectively prevented the formation of cracks on the IZTO film, underscoring their pivotal role in enhancing the mechanical robustness of IZTO. In summary, this research highlights the potential of PMMA and CYTOP as efficient encapsulation materials for IZTO-based flexible transparent electrodes, offering dual benefits in terms of optical performance and mechanical durability.

Ultrathin, Mechanically Robust Quasi-Solid Composite Electrolyte for Solid-State Lithium Metal Batteries.

Herein, we present the preparation and properties of an ultrathin, mechanically robust, quasi-solid composite electrolyte (SEO-QSCE) for solid-state lithium metal battery (SLB) from a well-defined polystyrene-b-poly(ethylene oxide) diblock copolymer (SEO), Li6.75La3Zr1.75Ta0.25O12 nanofiller, and fluoroethylene carbonate plasticizer. Compared with the ordered lamellar microphase separation of SEO, the SEO-QSCE displays bicontinuous phases, consisting of a Li+ ion conductive poly(ethylene oxide) domain and a mechanically robust framework of the polystyrene domain. Therefore, the 12 μm-thick SEO-QSCE membrane exhibits an exceptional ionic conductivity of 1.3 × 10-3 S cm-1 at 30 °C, along with a remarkable tensile strength of 5.1 MPa and an elastic modulus of 2.7 GPa. The high mechanical robustness and the self-generated LiF-rich SEI enable the SEO-QSCE to have an extraordinary lithium dendrite prohibition effect. The SLB of Li|SEO-QSCE|LiFePO4 reveals superior cycling performances at 30 °C for over 600 cycles, maintaining an initial discharge capacity of 145 mAh g-1 and a remarkable capacity retention of 81% (117 mAh g-1) after 400 cycles at 0.5 C. The high-voltage SLB of Li|SEO-QSCE|LiNi0.5Co0.3Mn0.2O2 displays good cycling stability for over 150 cycles at 30 °C. Moreover, the exceptional robustness of SEO-QSCE enables the high-voltage solid-state pouch cell of Li|SEO-QSCE|LiNi0.5Co0.3Mn0.2O2 with high flexibility and excellent safety features. The current investigation delivers a promising and innovative approach for preparing quasi-solid electrolytes with features of ultrathin design, mechanical robustness, and exceptional electrochemical performance for high-voltage SLBs.

Design of mechanically robust, recyclable, multi-stimuli-responsive shape memory elastomers based on biological phytic acid and cuttlefish ink

Facilitating the utilization of biomass in the rubber field is a facile strategy to reduce environmental pollution and the carbon emission. Herein, biological phytic acid (PA) was served as an eco-friendly curing agent, and cuttlefish ink (CI) was acted as a photothermal trigger switch to fabricate multi-stimuli-responsive shape memory biobased epoxidized natural rubber (ENR) with mechanical robustness and recyclable ability. ENR was vulcanized by PA via the ring-opening reaction between phosphate groups of PA and epoxy group of ENR, leading to the construction of an impeccable cross-linking network and an adjustable Tg gradient, which endowed the elastomers with improved mechanical properties and shape memory effect. Meanwhile, the topology rearrangement occurred at elevated temperatures relied on phosphate transesterification, leading to excellent thermo-activated recyclable ability and reconfigurable shape memory performance of the elastomers. Additionally, CI acted as reinforced filler to enhance the ENR matrix, enabling elastomers to achieve a robust tensile strength of 21.4 MPa and tensile toughness of 30.4 MJ/m3, which was nearly 26.8 times and 11.3 times of the neat ENR, respectively. Exhilaratingly, CI also acted as photothermal trigger switch for the response to near-infrared light and sun, which realized the remotely multistage shape memory performance, demonstrating the potential application of ENR in the field of actuators without environmental pollution.

Dimerized Acceptors with Conjugate‐Break Linker Enable Highly Efficient and Mechanically Robust Organic Solar Cells

AbstractDesigning new acceptors is critical for intrinsically stretchable organic solar cells (IS‐OSCs) with high efficiency and mechanical robustness. However, nearly all stretchable polymer acceptors exhibit limited efficiency and high‐performance small molecular acceptors are very brittle. In this regard, we select thienylene‐alkane‐thienylene (TAT) as the conjugate‐break linker and synthesize four dimerized acceptors by the regulation of connecting sites and halogen substitutions. It is found that the connecting sites and halogen substitutions considerably impact the overall electronic structures, aggregation behaviors, and charge transport properties. Benefiting from the optimization of the molecular structure, the dimerized acceptor exhibits rational phase separation within the blend films, which significantly facilitates exciton dissociation while effectively suppressing charge recombination processes. Consequently, FDY‐m‐TAT‐based rigid OSCs render the highest power conversion efficiency (PCE) of 18.07 % among reported acceptors containing conjugate‐break linker. Most importantly, FDY‐m‐TAT‐based IS‐OSCs achieve high PCE (14.29 %) and remarkable stretchability (crack‐onset strain [COS]=18.23 %), significantly surpassing Y6‐based counterpart (PCE=12.80 % and COS=8.50 %). To sum up, these findings demonstrate that dimerized acceptors containing conjugate‐break linkers have immense potential in developing highly efficient and mechanically robust OSCs.