Performance analysis is an important tool for gymnasts and coaches to assess the techniques, strengths, and weaknesses of rhythmic gymnasts during training. To have an accurate insight about the motion and postures can help the optimization of their performance and offer personalized suggestions. However, there are three primary limitations of traditional performance analysis systems applied in rhythmic gymnastics: (1) Inability to quantify anthropometric data in an imperceptible way, (2) labor-intensive nature of data labeling and analysis, and (3) lack of monitoring of all-round and multi-dimensional perspectives of the target. Thus, an advanced performance analysis system for rhythmic gymnastics is proposed in this paper, powered by intelligent fabric. The system uses intelligent fabric to detect the physiological and anthropometric data of the gymnasts. After a variety of data are collected, the analysis component is implemented by artificial intelligence techniques resulting in behavior recognition, decision-making, and other functions assisting performance improvement. A feasible solution to implementing the analysis component is the use of the hyperdimensional computing technique. In addition, four typical applications are presented to improve training performance. Powered by intelligent fabric, the proposed advanced performance analysis system exhibits the potential to promote innovative technologies for improving training and competitive performance, prolonging athletic careers, as well as reducing sports injuries.
Fiber materials are highly desirable for wearable electronics that are expected to be flexible and stretchable. Compared with rigid and planar electronic devices, fiber-based wearable electronics provide significant advantages in terms of flexibility, stretchability and breathability, and they are considered as the pioneers in the new generation of soft wearables. The convergence of textile science, electronic engineering and nanotechnology has made it feasible to build electronic functions on fibers and maintain them during wear. Over the last few years, fiber-shaped wearable electronics with desired designability and integration features have been intensively explored and developed. As an indispensable part and cornerstone of flexible wearable devices, fibers are of great significance. Herein, the research progress of advanced fiber materials is reviewed, which mainly includes various material preparations, fabrication technologies and representative studies on different wearable applications. Finally, key challenges and future directions of fiber materials and wearable electronics are examined along with an analysis of possible solutions.
Neutral aqueous zinc ion batteries (ZIBs) have tremendous potential for grid-level energy storage and portable wearable devices. However, certain performance deficiencies of the components have limited the employment of ZIBs in practical applications. Recently, a range of pristine materials and their composites with fiber-based structures have been used to produce more efficient cathodes, anodes, current collectors, and separators for addressing the current challenges in ZIBs. Numerous functional materials can be manufactured into different fiber forms, which can be subsequently converted into various yarn structures, or interwoven into different 2D and 3D fabric-like constructions to attain various electrochemical performances and mechanical flexibility. In this review, we provide an overview of the concepts and principles of fiber-based materials for ZIBs, after which the application of various materials in fiber-based structures are discussed under different domains of ZIB components. Consequently, the current challenges of these materials, fabrication technologies and corresponding future development prospects are addressed.
Neutral aqueous zinc ion batteries (ZIBs) have tremendous potential for grid-level energy storage and portable wearable devices. However, certain performance deficiencies of the components have limited the employment of ZIBs in practical applications. Recently, a range of pristine materials and their composites with fiber-based structures have been used to produce more efficient cathodes, anodes, current collectors, and separators for addressing the current challenges in ZIBs. Numerous functional materials can be manufactured into different fiber forms, which can be subsequently converted into various yarn structures, or interwoven into different 2D and 3D fabric-like constructions to attain various electrochemical performances and mechanical flexibility. In this review, we provide an overview of the concepts and principles of fiber-based materials for ZIBs, after which the application of various materials in fiber-based structures are discussed under different domains of ZIB components. Consequently, the current challenges of these materials, fabrication technologies and corresponding future development prospects are addressed.
The success of high-power fiber lasers is fueled by maturation of active and passive fibers, combined with the availability of high-power fiber-based components. In this contribution, we first overview the enormous potential of rare-earth doped fibers in spectral coverage and recent developments of key fiber-based components employed in high-power laser systems. Subsequently, the emerging functional active and passive fibers in recent years, which exhibit tremendous advantages in balancing or mitigating parasitic nonlinearities hindering high-power transmission, are outlined from the perspectives of geometric and material engineering. Finally, novel functional applications of conventional fiber-based components for nonlinear suppression or spatial mode selection, and correspondingly, the high-power progress of function fiber-based components in power handling are introduced, which suggest more flexible controllability on high-power laser operations.
One of the leading causes of wound healing delays is bacterial infection, which limits the process of restoring the histological and functional integrity of the skin. Electrospun nanofibrous materials (ENMs) are biocompatible and biodegradable, and they can provide specific physical, chemical, and biological cues to accelerate wound healing. Based on this fact, a series of multifunctional ENMs for complex clinical applications, particularly infected skin injuries, have been developed. Antibiotics, antimicrobial peptides (AMPs), metals and metal oxides (MMOs), and antibacterial polymers have previously been incorporated into ENMs through advanced material processing techniques, endowing ENMs with enhanced and excellent antibacterial activity. This review summarizes wound healing issues and provides recent advances in antibacterial ENMs created by cutting-edge technology. The future of clinical and translational research on ENMs is also discussed.
Fiber-shaped photocapacitors (FPCs) based on shared bifunctional fiber electrodes for supercapacitors and solar cells hold great potential for the realization of self-powered systems for flexible wearable electronics. However, the reported electrodes for FPCs still face certain limitations, such as limited specific energy density, low total photochemical–electric energy conversion efficiency (ηtotal), and poor flexibility. Herein, hollow fibers consisting of partially reduced graphene oxide and a highly conductive polymer are assembled by wet-spinning and employed as shared bifunctional fibers to fabricate self-powered FPCs. Intriguingly, the FPCs achieve high flexibility and a ηtotal of 4.2%. This study illustrates a feasible way to design high-performance FPCs and their applications in flexible electronics.
Extensive progress has been achieved regarding Janus fabric for directional water transport due to its excellent and feasible personal cooling management ability, which has great significance for energy conservation, pollution reduction, and human health. However, existing Janus asymmetric multilayer fabrics for directional water transport are still limited by their complicated syntheses and poor stabilities. Inspired by the compositionally graded architecture of leaf cuticles, we propose a single-layer Janus personal cooling management fabric (JPCMF) via a one-step electrospinning method. The JPCMF shows not only great directional bulk water transport ability but also asymmetry moisture (water vapor) transport ability with a high asymmetry factor (1.49), water vapor transmission value (18.5 kg−1 m−2 D−1), and water evaporation rate (0.735 g h−1). Importantly, the JPCMF exhibits outstanding durability and stability thanks to a novel electrostatic adsorption-assisted self-adhesion strategy for resisting abrasion, peeling and pulling. With these characteristics, the JPCMF can achieve a 4.0 °C personal cooling management effect, better than taht of cotton fabric, on wet skin. The good biocompatibility and nontoxicity also endow the JPCMF with the potential to be a self-pumping dressing. Our strategy should facilitate a new method for developing next-generation intelligent multifunctional fabrics.
In the intelligent era, the textile technique is a high efficiency, mature and simple manufacturing solution capable of fabricating fully flexible wearable devices. However, the external circuit with its integration and comfort limitations cannot satisfy the requirements of intelligent wearable and portable devices. This study presents an industrialized production method to fabricate core–shell structure conductive yarn for direct textile use, prepared by the high-speed sirospun technique. Both integration and flexibility are significantly improved over previous works. Combining sirospun conductive yarn (SSCY) and the intarsia technique can provide the SSCY seamless and convenient embedded knitted circuit (SSCY-EKC) to form a full textile electrical element as the channel of power and signals transmission, allowing for a stable resistance change and wide strain range for meeting practical applications. SSCY based on the triboelectric nanogenerator (SSCY-TENG) can be designed as a caution carpet with attractive design and good washability for a self-powered sensor that recognizes human motions. Furthermore, intrinsic textile properties such as washability, softness, and comfort remained. With benefits such as excellent extension, fitting, and stretchability, the SSCY-EKC used herein can realize a fully flexible electrical textile with a high potential for physical detection, body gesture recognition, apparel fashion, and decoration.
Herein, g-C3N4 quantum-dot-modified TiO2 nanofibers were fabricated and used as an efficient photocatalyst for the investigation of the influence of Cu2+ and the interaction mechanism between Cu2+ and surface defects in tetracycline degradation. Results showed that the effect of Cu2+ switched from promoting to inhibiting the tetracycline degradation as the amount of Cu2+ accumulated on the catalyst surface increased. The introduction of surface defects can prevent the inhibiting effect of Cu2+, resulting in the more complete degradation of tetracycline in contrast to the non-defective sample. Theoretical calculations further revealed that the defects can be used to tune the conduction band of the composite, inducing the reduction reaction of Cu2+ and inhibiting the accumulation of Cu on the surface of catalysts. Moreover, the Cu introduced to the catalyst surface provided new active sites, thereby promoting photocatalytic degradation. These findings provide new insights into the design of advanced fiber materials for water purification in complex environments.
All-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) are emerging as promising candidate materials for optoelectronic devices due to their splendid optical and electrical properties. However, the intrinsic instability greatly limits their practical application. Herein, a feasible strategy is proposed for fabricating highly stable and luminescent CsPbBr3@PVDF-HFP/PS nanofibers by combining one-step electrospinning method with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFDTMS)-assisted post-treatment. The bright-emitting CsPbBr3 NCs can be effectively encapsulated within polymer nanofibers, which exhibit ultrafine diameter of only 88.1 ± 2.8 nm and high photoluminescence quantum yield (PLQY) of 87.9% via rationally optimizing the electrospinning parameters, concentration of perovskite precursors and ligands. Most importantly, the superhydrophobic surface structures of nanofibers are formed by the hydrolysis and condensation of PFDTMS under moist environment. Benefiting from the double effective protection of polymer matrices and hydrophobic PFDTMS oligomers against moisture erosion, the CsPbBr3@PVDF-HFP/PS nanofibers present an obviously improved stability, which can retain 90% initial PL intensity after water immersion for 70 days. Furthermore, an efficient white light-emitting diode with wide color gamut covering 117% of National Television System Committee (NTSC) standard is successfully fabricated based on the composite nanofiber membranes, suggesting their promising prospect for solid-state lighting and display applications.
Superfine perovskite nanofibers with efficient fluorescence and ultrahigh stability are fabricated by combining one-step electrospinning method with PFDTMS-assisted post-treatment.
Wearable devices redefine the way people interact with machines. Despite the intensive effort in the design and fabrication of synthetic fibers to improve wearable device properties in terms of electronic and ionic conductivity, stretchability, comfort, and washability, challenges remain in fabricating single fiber materials that optimize all properties simultaneously. In this work, we demonstrate a highly stretchable, ionic, and electronic conductive fabric via (1) the natural nanoscale channels in fibers for effective ion transportation, (2) confining the electronic conductive material with the cellulose fibers, and (3) decoupling the property degradation of the fiber from deformation using the knitted pattern. The hierarchical structure created by cotton fibers can serve as ionic conductive channels as well as a robust multiscale scaffold to host infiltrated electronic conductive materials. Cotton strands with ionic and electronic conductivity can be knitted into fabrics that are highly stretchable (~ 300%). Moreover, high ionic and electronic conductivity are observed with 2 S/m and 5 S/m, respectively, even under a strain of 175%. With the inherent advantages of cotton fabrics such as moisture-wicking, washability, comfort, and light-weightiness for wearable applications, our approach of directly functionalized cellulose can potentially be a promising route towards highly stretchable and wearable mixed conductors.
Malignant glioblastoma (GBM) is prone to relapse due to the inevitable tumor cells residue by surgery. During the tumor resection surgery in brain, addressing bleeding and superbug infections is also full of challenges. Currently, no method or material in clinical craniotomy can simultaneously solve these three problems. Herein, Chitosan composite nanofibers embedded with CuSe nanoparticles were prepared by green electrospinning method, in which the CuSe nanoparticles have strong absorption in the second near-infrared (NIR-II) window. Immediately after removing the tumor in craniotomy, nanofibers were electrospun and deposited directly onto the resection site with high precision (> 90%) to achieve rapid hemostasis (< 8 s). Moreover, evidenced by the deeper penetration depth of NIR-II light (1064 nm) both in the scalp and skull than NIR-I light (808 nm), photothermal and photodynamic therapy induced by NIR-II exhibits efficient superbug-killing rate (> 99%) and effectively induces cell apoptosis of residual tumor thereby to inhibit tumor recurrence. Only using the same material, a trilogy of intracranial hemostasis, killing superbug and residual cancer cells is simultaneously achieved. The short operation time reduces the risk of craniotomy. This electrospinning strategy could combine with craniotomy and minimally invasive surgery, which may provide novel perspectives in clinical operation besides craniotomy.
The exploration of smart electronic textiles is a common goal to improve people’s quality of life. However, current smart e-textiles still face challenges such as being prone to failure under humid or cold conditions, lack of washing durability and chemical fragility. Herein, a multifunctional strain sensor with a negative resistance change was developed based on the excellent elasticity of knitted fabrics. A reduced graphene oxide (rGO) conductive fabric was first obtained by electrostatic self-assembly of chitosan (CS). Then a strain sensor was prepared using a dip-coating process to adsorb nanoscale silica dioxide and poly(dimethylsiloxane) (PDMS). A broad working range of 60%, a fast response time (22 ms) and stable cycling durability over 4000 cycles were simultaneously achieved using the prepared sensor. Furthermore, the sensor showed excellent superhydrophobicity, photothermal effects and UV protection, as graphene, silica and PDMS acted in synergy. This multifunctional sensor could be mounted on human joints to perform tasks, including activity monitoring, medical rehabilitation evaluation and gesture recognition, due to its superior electromechanical capabilities. Based on its multiple superior properties, this sensor could be used as winter sportswear for athletes to track their actions without being impacted by water and as a warmer to ensure the wearer's comfort.
Bacterial infections and multidrug-resistant bacteria are major health burdens in wound care. Biocompatible antimicrobial agents, e.g., ε-polylysine (ε-PL), provide a broad spectrum of antibacterial properties and support dermal cell growth. Here, ε-PL was incorporated into polycaprolactone (PCL)/gelatin electrospun scaffolds collected at varying rotation speeds. Then, the samples were crosslinked using dopamine hydrochloride to provide highly proliferative dressings with broad antimicrobial activity. The morphological study showed that the electrospun wound dressings were smooth, continuous, and bead-free, with a mean diameter ranging from 267 ± 7 to 331 ± 8 nm for all random and aligned nanofibers. The fiber alignment of the electrospun PCL/gelatin scaffolds improved their tensile strength and modulus. Moreover, nanofiber mats are highly hydrophilic, which is crucial for an efficient wound dressing. The samples also demonstrated high antimicrobial properties against common wound bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus (SA), Escherichia coli (EC), Acinetobacter baumannii (AB), and Pseudomonas aeruginosa (PA). Mammalian cell proliferation and morphology assays involving primary human dermal fibroblasts (hDFs) and immortalized keratinocytes (HaCaT) showed excellent biocompatibility of the electrospun mats and remarkably aligned mats. Furthermore, aligned mats showed more cell migration than randomly oriented mats, which is desirable for more efficient wound healing. Therefore, it can be concluded that aligned PCL/gelatin mats containing ε-PL are promising for potential use in wound dressings.
It is especially important to coordinately design the structure and composition of the host in lithium–sulfur batteries (LSBs) for improving its physicochemical adsorption and conversion of lithium polysulfide, which can alleviate the harmful shuttle effect. Herein, a self-supporting multichannel nitrogen-doped carbon fibers membrane embedded with TiO nanoparticles (TiO@NC) was constructed as the electrode for LSBs. The inner channels and the embedded TiO nanoparticles offer spatial confinement and chemical binding for polysulfides, respectively. Moreover, the TiO nanoparticles have abundant oxygen vacancies that promote the conversion of polysulfides. In addition, the nitrogen-doped carbon skeleton can not only serve as highly conductive transportation paths for electrons, but also integrate with the inner channels to sustain the morphology and bear volume expansion during cycling processes. Therefore, the fabricated self-supporting quadruple-channel TiO@NC ultrathin fibers electrode exhibits a high initial specific capacity of 1342.8 mAh g−1 at 0.5 C and high-rate capability of 505.8 mAh g−1 at 4.0 C. In addition, it maintains 696.0 mAh g−1 over 500 cycles with only 0.059% capacity decay per cycle at the high current density of 2.0 C. The multichannel configuration combined with TiO nanoparticles provides a synergetic design strategy for fabricating high-performance electrodes in LSBs.
The okra-like multichannel TiO@NC membrane has a multiscale synergistic effect on polysulfides to restrict the shuttle effect in lithium–sulfur batteries. In macroscopic, the self-supporting fibers membrane offers a stable conductive network. In microscopic, the multiple channels provide long-range spatial confinement for polysulfides and alleviate volume expansion. In nanoscopic, TiO nanoparticles have chemical binding effect on polysulfides
BiOX (X = Cl, I, Br) has attracted intensive interest as a photocatalyst for environmental remediation, but its limited photocatalytic activity versus visible light irradiation restricts its practical application. Herein, a Fe3+-doped BiOClxI1–x solid solution (Fe-BiOClxI1–x) was synthesized in situ on an amidoxime-functionalized fibrous support via a one-pot solvothermal approach. Comprehensive characterization and DFT calculations indicate that the robust chelated interaction between amidoxime groups and Fe3+ greatly boosts the crystal growth of nanosized Fe-BiOClxI1–x on the fibrous surface, simultaneously tunes its electronic structure for improved light harvesting and oxygen vacancy creation, and enables the fibrous support to act as an electron sink for efficient charge separation. These synergistic qualities result in high photocatalytic activity for the degradation of organic contaminants, which outperforms that obtained for unsupported Fe-BiOClxI1–x and other fibrous samples by several times. Our findings highlight the importance of functionalized support design for the development of efficient BiOX photocatalysts under visible light irradiation.
Smart textiles with high sensitivity and rapid response for various external stimuli have gained tremendous attentions in human healthcare monitoring, personal heat management, and wearable electronics. However, the current smart textiles only acquire desired signal passively, regularly lacking subsequent on-demand therapy actively. Herein, a robust, breathable, and flexible smart textiles as multi-function sensor and wearable heater for human health monitoring and gentle thermotherapy in real time is constructed. The composite fiber as strain sensor (CFY@PU) was fabricated via warping carbon fiber yarns (CFY) onto polyurethane fibers (PU), which endowed composite fiber with high conductivity, excellent sensitivity (GF = 76.2), and fantastic dynamic durability (7500 cycles) in strain sensing. In addition, CFY@PU can detect various degrees of human movements such as elbow bending, swallowing and pulse, which can provide effective information for disease diagnosis. More surprisingly, weaving CFY@PU into a fabric can assemble highly sensitive pressure sensor for remote communication and information encryption. Warping CFY onto Kevlar would obtain temperature-sensitive composite fiber (CFY@Kevlar) as temperature sensor and wearable heater for on-demand thermotherapy, which provided unique opportunities in designing smart textiles with ultrahigh sensitivity, rapid response, and great dynamic durability.
Despite the impressive power conversion efficiency (PCE) beyond 25.5%, perovskite solar cells, especially the Sn-based variants, are poorly stable under normal operating conditions compared with the market-dominant silicon solar cells that can last for over 25 years. 2D3D hybrid perovskite materials are one of the best options to overcome the instability challenge without compromising efficiency. Indeed, a record performance of 1 year was reported in Pb-based 2D3D planar perovskite devices. However, the reaction between 2 and 3D perovskite molecules requires high temperatures (⁓ 300 °C) and increased reaction time (⁓ 24 h) to achieve high-quality 2D3D hybrid perovskites. Herein, we base on the ability of chlorine to displace iodine from its ionic compounds in solutions to utilize chloride ions as catalysts for speeding up the reaction between iodine-based 2D and 3D perovskite molecules. The approach reduces the reaction time to ⁓ 20 min and the reaction temperature to ⁓ 100 °C with the formation of high-quality 2D3D hybrid perovskites, free from pure 2D traces. Integrating the synthesized 2D3D hybrid perovskite material with 50% chlorine doping in a fiber-shaped solar cell architecture yielded the highest reported PCE of 11.96% in Sn-based fiber-shaped perovskite solar cells. The unencapsulated and encapsulated fiber-shaped solar cells could maintain 75% and 95.5% of their original PCE, respectively, after 3 months under room light and relative humidity of 35–40%, revealing the champion stability in Sn-based perovskite solar devices. The solar yarn also demonstrated constant energy output under changing light incident angles (0–180°).
Impaired wound healing imposes great health risks to patients. Recently, mesenchymal stem cell (MSC) therapy has shown potential to improve the healing process, but approaches to employ MSCs in the treatment of wounds remain elusive. In this study, we reported a novel electrohydrodynamic (EHD) cyroprinting method to fabricate micropatterned fiber scaffolds with polycaprolactone (PCL) dissolved in glacial acetic acid (GAC). Cyroprinting ensured the formation of a porous structure of PCL fibers by preventing the evaporation of GAC, thus increasing the surface roughness parameter Ra from 11 to 130 nm. Similar to how rough rocks facilitate easy climbing, the rough surface of fibers was able to increase the adhesion of adipose-derived MSCs (AMSCs) by providing more binding sites; therefore, the cell paracrine action of secreting growth factors and chemokines was enhanced, promoting fibroblast migration and vascular endothelial cell tube formation. In rat models with one-centimeter wound defects, enhanced MSC therapy based on porous PCL fiber scaffolds improved wound healing by augmenting scarless collagen deposition and angiogenesis and reducing proinflammatory reactions. Altogether, this study offers a new and feasible strategy to modulate the surface topography of polymeric scaffolds to strengthen MSC therapy for wound healing.
Tissue injury leads to gradients of chemoattractants, which drive multiple processes for tissue repair, including the inflammatory response as well as endogenous cell recruitment. However, a limited time window for the gradients of chemoattractants as well as their poor stability at the injury site may not translate into healthy tissue repair. Consequently, intelligent multifunctional scaffolds with the capability to stabilize injury-induced cytokines and chemokines hold great promise for tissue repair. Vascular endothelial growth factor (VEGF) plays a significant role in wound healing by promoting angiogenesis. The overarching objective of this research was to develop intelligent multifunctional scaffolds with the capability to endogenously recruit VEGF and promote wound healing via angiogenic and immunomodulatory dual functions. Prominin-1-derived peptide (PR1P) was encapsulated into electrospun poly(L-lactide-coglycolide)/gelatin (P/G)-based bandages. The sustained release of PR1P recruited VEGF in situ, thereby stabilizing the protein concentration peak in vivo and affording a reparative microenvironment with an adequate angiogenic ability at the wound site. Meanwhile, PR1P-recruited VEGF-induced macrophage reprogramming towards M2-like phenotypes further conferred immunomodulatory functions to the bandages. These dual functions of proangiogenesis and immunomodulation formed a cascade amplification, which regulated matrix metalloproteinases (MMP-9) as well as inflammatory factors (nuclear factor (NF)-κb, tumor necrosis factor (TNF)-α) in the wound microenvironment via the VEGF/macrophages/microenvironment axis. Consequently, the bandages realized multifunctional regeneration in splinted excisional wounds in rats, with or without diabetes, affording a higher skin appendage neogenesis, sensory function, and collagen remodeling. Conclusively, our approach encompassing in situ recruitment of VEGF at the injury site with the capability to promote immunomodulation-mediated tissue repair affords a promising avenue for scarless wound regeneration, which may also have implications for other tissue engineering disciplines.
Skin regeneration is a matter of high concern since many individuals suffer from skin damage. To date, the concept of protein-based artificial skin scaffolds have been successfully applied and proven in skin regeneration. However, realizing a skin tissue scaffold with a skin-like extracellular matrix (ECM) that combines low price, good biocompatibility, excellent antibacterial properties, good cell adhesion, and strong mechanical properties is still a major challenge. In this study, inexpensive silk sericin (SS) protein-based artificial skin nanofiber scaffolds (NFSs) with excellent biological activity, no immune rejection, and high mechanical strength were fabricated via microfluidic blow-spinning (MBS). In particular, the as-prepared NFS was transformed from a random coil structure to a $\upbeta$-sheet structure by using the MBS in high-speed shear chips to improve its stability and mechanical strength. Additionally, through in vitro and in vivo studies, it was shown that SS protein-based artificial skin NFSs possessed excellent antibacterial effects and degradability properties, as well as accelerated tissue granulation growth, effectively promoting full skin wound healing and skin regeneration for medical problems worldwide. Thus, this skin ECM-inspired NFS offers new perspectives for accelerating wound healing and tissue regeneration and provides potential applications for clinical medicine.
Portable energy solutions are highly desired in the era of the Internet of Things for powering various distributed microelectronic devices. At the same time, the energy crisis and catastrophic global warming are becoming serious problems in the world, emphasizing the urgent need for clean and renewable energy. Here, we report a low-cost, high-performance, and portable hand-driven whirligig structured triboelectric–electromagnetic hybrid nanogenerator (whirligig-HNG) for multi-strategy energy harvesting. The whirligig-HNG comprises a dynamic supercoiling TENG via the pulling-strings and inner-distributed EMGs (variable number) in the rotator. The whirligig structure can readily convert linear displacement in low frequency into rotary motion in extremely high frequency. Based on this ingenious design, the whirligig-HNG is capable to harvest the triboelectric energy from the supercoiling/uncoiling process from the pulling strings and simultaneously utilize the high-frequency rotation energy via electromagnetic induction. We have systematically investigated the working mechanism of the whirligig-HNG for coupled energy harvesting and compared the individual characteristics of TENG and EMG. The whirligig-HNG is successfully demonstrated to light up more than 100 commercial light-emitting diodes (LEDs) and drive portable electronics. This research presents the enormous potential of whirligig-HNG as a manual and portable power supply for powering various portable electronics.
Fluorine atoms confer desirable biophysical, chemical, and biological properties to peptides/proteins by participating in various intermolecular interactions with their environment, but they are rarely used to control supramolecular chirality and functional. Herein, to identify the effects of fluorine substitution on the chirality and function of supramolecular assemblies, C2-symmetric benzene-paradicarboxamide-based phenylalanine (phe) derivatives and three monofluorinated variants that had a single fluorine atom on their benzyl side chain in either the ortho, meta, or para position were synthesized. The experimental and theoretical results clearly show that the resulting assembled fibrils were supported by multiple interactions, including hydrogen bonding, π–π stacking and C/O–H···F–CAr interactions. Compared to nonfluorinated analogs, fluorine and its ring position on the aromatic side chain dictated the type and strength of the F···H interaction and then induced changes in supramolecular chirality and fiber morphology. Further studies on cell behavior showed that the order of positive interaction between high-order supramolecular chirality (M, P) and molecular chirality (L, D) on cell proliferation and viability is LM > DM > LP > DP. These findings provide a protocol for leveraging fluorine atoms and their positional dependence on directing chiral nanostructures with desirable handedness and creating fluorinated supramolecular hydrogels as extracellular matrix-mimetic scaffolds for cell culture and regenerative medicine.
The helical chirality can be reversed by introducing a fluorine atom into the supramolecular system and changing its ring position on the aromatic side chain, which are attributed to fluorous interactions dictate the helical orientation and morphology of supramolecular assemblies.
Diabetic wounds have become a major clinical problem that cannot be ignored. Gases, such as hydrogen sulphide (H2S), have demonstrated value in inducing angiogenesis and accelerating wound healing, while their effective delivery is still challenging. Here, inspired by the continuous-independent hollow structure of bamboo, we propose novel gasotransmitter microfibres with septal H2S bubbles using microfluidic spinning for diabetic wound healing. Benefitting from the exact control of microfluidics, gasotransmitter microfibres with different bubble sizes and morphologies could be generated successfully and continuously. Under the dual effects of drugs in the shell and gas in the core, the wound healing process could be accelerated. Furthermore, the controllable release of drugs could be achieved by adding responsive materials into the microfiber shell, which would promote continuous effects of contents on demand. Based on in vitro and in vivo studies, we have proven that these gasotransmitter microfibres have a positive impact on inducing angiogenesis and promoting cell proliferation during wound healing. Thus, it is believed that the bamboo-inspired gasotransmitter microfibres will have important value in gasotransmitter research and clinical applications.
The bamboo-inspired microfibres are presented through microfluidics with features of independent chambers for storing and controlled release of hydrogen sulphide (H2S) to the diabetic wound. Even if it is partially damaged, it will not affect the overall gas storage and utilization. Thus, it contributes to improvements in basic research and the transformation of gasotransmitters.