Humanoid Intelligent Display Platform for Audiovisual Interaction and Sound Identification

This study proposes a rational strategy for the design,fabrication and system integration of the humanoid intelligent display platform(HIDP)to meet the requirements of highly humanized mechanical properties and intelligence for human-machine interfaces.The platform’s sandwich structure comprises a middle lightemitting layer and surface electrodes,which consists of silicon elastomer embedded with phosphor and silk fibroin ionoelastomer,respectively.Both materials are highly stretchable and resilient,endowing the HIDP with skin-like mechanical properties and applicability in various extreme environments and complex mechanical stimulations.Furthermore,by establishing the numerical correlation between the amplitude change of animal sounds and the brightness variation,the HIDP realizes audiovisual interaction and successful identification of animal species with the aid of Internet of Things(IoT)and machine learning techniques.The accuracy of species identification reaches about 100%for 200 rounds of random testing.Additionally,the HIDP can recognize animal species and their corresponding frequencies by analyzing sound characteristics,displaying real-time results with an accuracy of approximately 99%and 93%,respectively.In sum,this study offers a rational route to designing intelligent display devices for audiovisual interaction,which can expedite the application of smart display devices in human-machine interaction,soft robotics,wearable sound-vision system and medical devices for hearing-impaired patients.

Thermochromic Silks for Temperature Management and Dynamic Textile Displays

Silks have various advantages compared with synthetic polymer fibers,such as sustainability,mechanical properties,luster,as well as air and humidity permeability.However,the functionalization of silks has not yet been fully developed.Functionalization techniques that retain or even improve the sustainability of silk production are required.To this end,a low-cost,effective,and scalable strategy to produce TCSs by integrating yarn-spinning and continuous dip coating technique is developed herein.TCSs with extremely long length(>10 km),high mechanical performance(strength of 443.1 MPa,toughness of 56.0 MJ m−3,comparable with natural cocoon silk),and good interfacial bonding were developed.TCSs can be automatically woven into arbitrary fabrics,which feature super-hydrophobicity as well as rapid and programmable thermochromic responses with good cyclic performance:the response speed reached to one second and remained stable after hundreds of tests.Finally,applications of TCS fabrics in temperature management and dynamic textile displays are demonstrated,confirming their application potential in smart textiles,wearable devices,flexible displays,and human–machine interfaces.Moreover,combination of the fabrication and the demonstrated applications is expected to bridge the gap between lab research and industry and accelerate the commercialization of TCSs.

Ultrastable and High-Performance Silk Energy Harvesting Textiles

Energy harvesting textiles(EHTs)have attracted much attention in wearable electronics and the internet-of-things for real-time mechanical energy harvesting associated with human activities.However,to satisfy practical application requirements,especially the demand for long-term use,it is challenging to construct an energy harvesting textile with elegant trade-off between mechanical and triboelectric performance.In this study,an energy harvesting textile was constructed using natural silk inspired hierarchical structural designs combined with rational material screening;this design strategy provides multiscale opportunities to optimize the mechanical and triboelectric performance of the final textile system.The resulting EHTs with traditional advantages of textiles showed good mechanical properties(tensile strength of 237±13 MPa and toughness of 4.5±0.4 MJ m−3 for single yarns),high power output(3.5 mW m−2),and excellent structural stability(99%conductivity maintained after 2.3 million multi-type cyclic deformations without severe change in appearance),exhibiting broad application prospects in integrated intelligent clothing,energy harvesting,and human-interactive interfaces.

Correction to:Ultrastable and High-Performance Silk Energy Harvesting Textiles

In the original publication,there is line dislocation in Fig.8d.The correct Fig.8 is provided in this correction.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were made.

Silk-derived peptide nanospirals assembled by self-propelled wormlike filaments

Swirl-like nanospiral is a common structure found in free-swimming biological systems,such as microtubules and actin filaments or slender bacteria.It is desired for artificially designed dynamic nanomaterials.However,the spiral formation has rarely been reported in both engineered peptides and regenerated proteins.Herein,we report that such a unique assembly behavior can be achieved by using a fusion peptide consisting of a silk-derived peptide(i.e.,GAGAGAGY)and a hydrophobic,photoresponsive azobenzene(Azo)segment.In this fusion structure,GAGAGAGY acts as a domain that spontaneously forms an elongated filament in an aqueous solution,while Azo acts as a"light-operated switch"that can undergo photoinduced isomerization to modulate the self-propulsion forces and assembly behavior.With this design,the critical factors that affect the assembly of Azo-GAGAGAGY filament,including(i)length and flexibility of filaments;(ii)propulsion,and(iii)excluded volume interactions force the tip of the filament to wind up,can be regulated to realize the spiral formation.In addition,the configurations of Azo-GAGAGAGY filaments,such as straight nanoribbons,wavy nanoribbons,single-circle spiral,and multiple-circle spiral,can be facilely mediated by changing the preparation procedure,concentration,and pH value of Azo-GAGAGAGY solution,as these changes have significant influences on self-propulsion forces.Our findings can help in the better understanding of nonequilibrium thermodynamics and collective behavior of biological systems.The findings can be used as a guideline for the designs of nanoactuators,microswimmers,transformable microrobots,and intelligent drug carriers.

In-situ growth of low-dimensional perovskite-based insular nanocrystals for highly efficient light emitting diodes

Regulation of perovskite growth plays a critical role in the development of high-performance optoelectronic devices.However,judicious control of the grain growth for perovskite light emitting diodes is elusive due to its multiple requirements in terms of morphology,composition,and defect.Herein,we demonstrate a supramolecular dynamic coordination strategy to regulate perovskite crystallization.The combined use of crown ether and sodium trifluoroacetate can coordinate with A site and B site cations in ABX_(3) perovskite,respectively.The formation of supramolecular structure retard perovskite nucleation,while the transformation of supramolecular intermediate structure enables the release of components for slow perovskite growth.This judicious control enables a segmented growth,inducing the growth of insular nanocrystal consist of low-dimensional structure.Light emitting diode based on this perovskite film eventually brings a peak external quantum efficiency up to 23.9%,ranking among the highest efficiency achieved.The homogeneous nano-island structure also enables high-efficiency large area(1 cm^(2))device up to 21.6%,and a record high value of 13.6%for highly semi-transparent ones.

Biopolymer Nanofibers for Nanogenerator Development

The development of nanogenerators(NGs)with optimal performances and functionalities requires more novel materials.Over the past decade,biopolymer nanofibers(BPNFs)have become critical sustainable building blocks in energy-related fields because they have distinctive nanostructures and properties and can be obtained from abundant and renewable resources.This review summarizes recent advances in the use of BPNFs for NG development.We will begin by introducing various strategies for fabricating BPNFs with diverse structures and performances.Then,we will systematically present the utilization of polysaccharide and protein nanofibers for NGs.We will mainly focus on the use of BPNFs to generate bulk materials with tailored structures and properties for assembling of triboelectric and piezoelectric NGs.The use of BPNFs to construct NGs for the generation of electricity from moisture and osmosis is also discussed.Finally,we illustrate our personal perspectives on several issues that require special attention with regard to future developments in this active field.

Violin String Inspired Core-Sheath Silk/Steel Yarns for Wearable Triboelectric Nanogenerator Applications

Triboelectric nanogenerator(TENG)has attracted considerable attention in wearable electronics and energy harvesting associated with human activities.Fiber/yarn electrodes are widely applied in the wearable TENG system,which remains a challenge to guarantee mechanical ductility and stable electrical functions during long-term use.Inspired by high quality violin strings core-sheath design,silk/stainless-steel integrated yarns(SSYs)are continuously produced by simple co-wrapping spinning technique,which shows excellent mechanical strength,flexibility,conductivity,weaveability and triboelectric function.The SSYs can be modified to achieve tunable surface morphology.Finally,TENG cables have been fabricated,which can be stretched up to 100%and reveal a fast responsiveness to the stretching extent(voltage output of about 0.2,0.6,1.8,2.8 V at 13%,25%,38%,50%stretching,respectively).The TENG cables integrated textiles can not only harvest the energy generated by body movement but can also work as a self-supplied motion detector.

Silk Fibroin Nacre

Producing lightweight,mechanically strong,ductile,and biocompatible materials remains a significant challenge in material engineering due to the conflict between structural and mechanical features.Inspired by the“brick-and-mortar”structure of nacre,a construction with a naturally optimized structure-performance-function relationship,this study developed silk fibroin(SF)nacre as a silk protein-based nacre by integrating ice-templating and thermoplastic molding techniques.SF nacres are similar to natural nacre in microstructure,and their strength and toughness are even superior to natural nacres.These mechani-cal properties permit machining by extreme processing techniques,such as ion beam lithography.Furthermore,SF nacre can be used to modulate the polarization of laser beams and generate bright structural colors.Biocompatibility,mechanical robustness,good processability,and tunable coloration allow SF nacres to be used as a plastic replacement for structural engineering and biomedical use,showing promising advancement of such implantable devices towards clinical translation.

Nanofibril Organization in Silk Fiber as Inspiration for Ductile and Damage-Tolerant Fiber Design

Ductile and damage-tolerant fibers(DDTFs)are desired in aerospace engineering,mechanical engineering,and biomedical engineering because of their ability to prevent the catastrophic sudden structural/mechanical failure.However,in practice,design and fabrication of DDTFs remain a major challenge due to finite fiber size and limited processing techniques.In this regard,animal silks can provide inspirations.They are hierarchically structured protein fibers with an elegant trade-off of mechanical strength,extensibility and damage tolerance,making them one of the toughest materials known.In this article,we confirmed that nanofibril organization could improve the ductility and damage-tolerance of silk fibers through restricted fibril shearing,controlled slippage and cleavage.Inspired by these strategies,we further established a rational strategy to produce polyamide DDTFs by combining electrospinning and yarn-spinning techniques.The resultant polymeric DDTFs show a silk-like fracture resistance behavior,indicating potential applications in smart textile,biomedicine,and mechanical engineering.

Quantitative Evaluation of Pseudo Strain Signals Caused by Yarn Structural Deformation

Yarn-based strain sensors(YSSs)have shown great promising in the fabrication of wearable devices for their good comfortability and fexible designability.However,the false signals generated by the changes in the yarn structure of the YSSs are usually ignored.In this study,the generation,the characteristic,and the prediction of these signals were investigated.We recognized that these signals are composed of two negative pseudo peaks and a spurious resistance response plateau.These responses are found to have nothing in common with a true tensile strain,but be attributed to plastic deformation of the fbers.This is due to the fact that the deformation of YSSs exceeds the linear elastic range of the fbers.Although the use of pure elastic fbers can eliminate the spurious resistance response plateau,it will lead to an increase in the pseudo peak to the value compared with a true strain signal peak.Hence,a theoretical model was established to decouple the real signals from the false responses,ensuring the high sensing accuracy of YSSs for applications in wearable devices and artifcial intelligence interfaces.This work provides an in-depth understanding of the response of the YSSs,which might provide inspiration and guidance in the design of high-accuracy fber-based strain sensors.