Predicting the Mechanical Behavior of a Bioinspired Nanocomposite through Machine Learning

The bioinspired nacre or bone structure represents a remarkable example of tough,strong,lightweight,and multifunctional structures in biological materials that can be an inspiration to design bioinspired high-performance materials.The bioinspired structure consists of hard grains and soft material interfaces.While the material interface has a very low volume percentage,its property has the ability to determine the bulk material response.Machine learning technology nowadays is widely used in material science.A machine learning model was utilized to predict the material response based on the material interface properties in a bioinspired nanocomposite.This model was trained on a comprehensive dataset of material response and interface properties,allowing it to make accurate predictions.The results of this study demonstrate the efficiency and high accuracy of the machine learning model.The successful application of machine learning into the material property prediction process has the potential to greatly enhance both the efficiency and accuracy of the material design process.

Bioinspired fish-scale-like magnesium composites strengthened by contextures of continuous titanium fibers:Lessons from nature

Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers.The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures.In particular,the double-Bouligand architecture can effectively deflect cracking paths,alleviate strain localization,and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite,representing a successful implementation of the property-optimizing mechanisms in fish scales.The strength of the composites,specifically the effect of their bioinspired architectures,was interpreted based on the adaptation of classical laminate theory.This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.

Energy-absorbing porous materials:Bioinspired architecture and fabrication

Energy-absorbing materials are widely used in transportations,sports,and the military applications.Particularly,porous materials,including natural and artificial materials,have attracted tremendous attentions due to their light weight and excellent energy absorption capability.This review summarizes the recent progresses in the natural and artificial energy-absorbing porous materials.First,we review the typical natural porous materials including cuttlebone,bighorn sheep horn,pomelo peel,and sunflower stem pith.The architectures,energy absorption abilities,and mechanisms of these typical natural materials and their bioinspired materials are summarized.Then,we provide a review on the fabrication methods of artificial energy-absorbing porous materials,such as conventional foaming and three-dimensional(3D)printing.Finally,we address the challenges and prospects for the future development of energy-absorbing porous materials.More importantly,our review provides a direct guidance for the design and fabrication of energy-absorbing porous materials required for various engineering applications.

Self-Exfoliation of Flake Graphite for Bioinspired Compositing with Aramid Nanofiber toward Integration of Mechanical and Thermoconductive Properties

Flexible yet highly thermoconductive materials are essential for the development of next-generation flexible electronic devices.Herein,we report a bioinspired nanostructured film with the integration of large ductility and high thermal conductivity based on self-exfoliated pristine graphene and three-dimensional aramid nanofiber network.A self-grinding strategy to directly exfoliate flake graphite into few-layer and few-defect pristine graphene is successfully developed through mutual shear friction between graphite particles,generating largely enhanced yield and productivity in comparison to normal liquid-based exfoliation strategies,such as ultrasonication,high-shear mixing and ball milling.Inspired by nacre,a new bioinspired layered structural design model containing three-dimensional nanofiber network is proposed and implemented with an interconnected aramid nanofiber network and high-loading graphene nanosheets by a developed continuous assembly strategy of sol-gel-film transformation.It is revealed that the bioinspired film not only exhibits nacre-like ductile deformation behavior by releasing the hidden length of curved aramid nanofibers,but also possesses good thermal transport ability by directionally conducting heat along pristine graphene nanosheets.

Daytime Radiative Cooling:Artificial and Bioinspired Strategies

Traditional cooling systems have been posing a significant challenge to the global energy crisis and climate change due to the high energy consumption of the cooling process.In recent years,the emerging daytime radiative cooling provides a promising solution to address the bottleneck of traditional cooling technology by passively dissipating heat radiation to outer space without any energy consumption through the atmospheric transparency window(8~13μm).Whereas its stringent optical criteria require sophisticated and high cost fabrication producers,which hinders the applicability of radiative cooling technology.Many efforts have been devoted to develop high-efficiency and low-cost daytime radiative cooling technologies for practical application,including the nanophotonics based artificial strategy and bioinspired strategy.In order to systematically summarize the development and latest advance of daytime radiative cooling to help developing the most promising approach,here in this paper we will review and compare the two typical strategies on exploring the prospect approach for applicable radiative cooling technology.We will firstly sketch the fundamental of radiative cooling and summarize the common methods for construction radiative cooling devices.Then we will put an emphasis on the summarization and comparison of the two strategies for designing the radiative cooling device,and outlook the prospect and extending application of the daytime radiative cooling technology.

Nature-inspired materials and designs for flexible lithium-ion batteries

Flexible lithium-ion batteries(FLBs)are of critical importance to the seamless power supply of flexible and wearable electronic devices.However,the simultaneous acquirements of mechanical deformability and high energy density remain a major challenge for FLBs.Through billions of years of evolutions,many plants and animals have developed unique compositional and structural characteristics,which enable them to have both high mechanical deformability and robustness to cope with the complex and stressful environment.Inspired by nature,many new materials and designs emerge recently to achieve mechanically flexible and high storage capacity of lithiumion batteries at the same time.Here,we summarize these novel FLBs inspired by natural and biological materials and designs.We first give a brief introduction to the fundamentals and challenges of FLBs.Then,we highlight the latest achievements based on nature inspiration,including fiber-shaped FLBs,origami and kirigami-derived FLBs,and the nature-inspired structural designs in FLBs.Finally,we discuss the current status,remaining challenges,and future opportunities for the development of FLBs.This concise yet focused review highlights current inspirations in FLBs and wishes to broaden our view of FLB materials and designs,which can be directly“borrowed”from nature.

Bioinspired nanocomposites with self-adaptive mechanical properties

Conventional synthetic materials have fixed mechanical properties and suffer defects,damage,and degradation over time.This makes them unable to adapt to changing environments and leads to limited lifecycles.Recently,self-adaptive materials inspired by natural materials have emerged as a solution to address these problems.With the ability to change their mechanical properties based on changing mechanical environments,repairing defects,and maintaining their mechanical properties,these materials can lead to improved performance while decreasing waste.In this review,we explore self-adaptive phenomena found in nature that have inspired the development of synthetic self-adaptive materials,and the mechanisms that have been employed to create the next generation of materials.The potential applications of these materials,the challenges that existing approaches face,and future research opportunities are also discussed.

基于天然指状蔷薇珊瑚礁结构的仿生珊瑚修复材料

在对天然指状蔷薇珊瑚礁(Md CR)进行了全面化学成分、物理形貌及力学性能分析的基础上,以白水泥(WCE)为基底,通过添加发泡剂(LG-2258)和壳聚糖(CS),模拟Md CR的化学组成及物理结构,制备了3种Md CR仿生材料。通过SEM、FTIR、EDS、ICP-OES和微机控制电子万能试验机对Md CR及Md CR仿生材料进行了结构表征、化学成分测定和性能测试,并将Md CR移植到仿生材料上,放置于模拟海水中进行了为期6个月人工培育。结果表明,Md CR仿生材料具有与Md CR相似的孔隙结构、力学性能及化学组成;珊瑚虫可附着在仿生材料表面生长出新的珊瑚组织,Md CR在仿生材料表面培育平均增长10.36 mm。

Bioinspired designs in active metal-based batteries

Active metal-based batteries are drawing increased attention because of their inherent high energy density and specific capacity.Some grand challenges,such as dendrite growth,electrode degradation,rapid performance fading,etc.,have limited their practical application.Bioinspiration,which involves taking cues from the structures and functions of the natural world,can lead to a wealth of conceptually fresh approaches to regulator the metal ion transportation to achieve a dendrite-free metal plating,thwart the side-reaction reactions,and retard the structural distortions,for a more reliable and secure operation of active metal-based batteries.In this review,we concentrate on the fabrication and application of bioinspired designs in active metal-based batteries with enhanced performance,along with discussion on the challenges and opportunities associated with this promising topic.We anticipate that this review can offer some insights into the development of functional materials by learning from nature and provide some approaches for the innovations of either the battery structures or the energy materials for metal-based batteries.

Bioinspired Self-Healing Organic Materials： Chemical Mechanisms and Fabrications

Design and preparation of organic materials having the ability to automatically restore their mechanical and physical properties are of great importance because of the extensive application ranging from aerospace components to microcircuitry, where the accessibility is highly limited and the reparability of materials is lower. The self-healing behavior is actually a dy- namic property of material, resembling what is possessed by nature living systems. Therefore, fabrication of most self-healing materials is actually inspired by nature. This tutorial review focuses on the basic chemical mechanisms that have been suc- cessfully adopted in designing self-healing organic materials. It specially covers recent development in the design of materials with durable, easy repairable or self-healing superhydrophobic surfaces and coatings.

Bioinspired design of hybrid composite materials

Mimicking the natural design motifs of structural biological materials is a promising approach to achieve a unique combination of strength and toughness for engineering materials.In this study,we proposed a 2D computational model,which is a two-hierarchy hybrid composite inspired by the ultrastructural features of bone.The model is composed of alternating parallel array of two subunits(A&B)mimicking‘mineralized collagen fibril’and‘extrafibrillar matrix’of bone at ultrastructural level.The subunit-A is formed by short stiff platelets embedded within a soft matrix.The subunit-B consists of randomly distributed stiff grains bonded by a thin layer of tough adhesive phase.To assess the performance of the bioinspired design,a conventional unidirectional long-fiber composite made with the same amount of hard and soft phases was studied.The finite element simulation results indicated that the toughness,strength and elastic modulus of the bioinspired composite was 312%,83%,and 55%of that of the conventional composite,respectively.The toughness improvement was attributed to the prevalent energy-dissipating damage of adhesive phase in subunit-B and crack-bridging by subunit-A,the two major toughening mechanisms in the model.This study exemplifies some insights into natural design of materials to gain better material performance.

Biological and bioinspired materials: Structure leading to functional and mechanical performance

Nature has achieved materials with properties and mechanisms that go far beyond the current know-how of the engineering-materials industry.The remarkable efficiency of biological materials,such as their exceptional properties that rely on weak constituents,high performance per unit mass,and diverse functionalities in addition to mechanical properties,has been mostly attributed to their hierarchical structure.Key strategies for bioinspired materials include formulating the fundamental understanding of biological materials that act as inspiration,correlating this fundamental understanding to engineering needs/problems,and fabricating hierarchically structured materials with enhanced properties accordingly.The vast,existing literature on biological and bioinspired materials can be discussed in terms of functional and mechanical aspects.Through essential representative properties and materials,the development of bioinspired materials utilizes the design strategies from biological systems to innovatively augment material performance for various practical applications,such as marine,aerospace,medical,and civil engineering.Despite the current challenges,bioinspired materials have become an important part in promoting innovations and breakthroughs in the modern materials industry.

Bioinspired Adaptive Gel Materials with Synergistic Heterostructures

In nature, many biological soft tissues with synergistic heterostructures, such as sea cucumbers, skeletal muscles and cartilages, exhibit high functionality to adapt to complex environments. In artificial soft materials, hydrogels are similar to biological soft tissues due to the unique integration of ＂soft and wet＂ properties and elastic characteristics. However, currently hydrogel materials lack their necessary adaptability, including narrow working temperature windows and uncontrollable mechanics, thus restrict their engineering application in complex environments. Inspired by abovementionedbiological soft tissues, researchers have increasingly developed heterostructural gel materials as functional soft materials with high adaptability to various mechanical and environmental conditions. This article summarizes our recent work on high-performance adaptive gel materials with synergistic heterostructures, including the critical design criteria and the state-of-the-art fabrication strategies of our gel materials. The functional adaptation properties of these heterostructural gel materials are also presented in details, including temperature, wettability, mechanical and shape adaption.

Construction and application of bioinspired nanochannels based on two-dimensional materials

With the development of nanotechnology and materials science,bioinspired nanochannels appeared by mimicking the intelligent functions of biological ion channels.They have attracted a great deal of at-tention in recent years due to their controllable structure and tunable chemical properties.Inspired by the layered microstructure of nacre,2D layered materials as excellent matrix material of nanochannel come into our field of vision.Bionic nanochannels based on 2D materials have the advantages of facile preparation,tunable channel size and length,easy expansion,and modification,etc.Therefore,the 2D layered nanofluid system based on bionic nanochannels from 2D layered materials has great potential in biomimetic microsensors,membrane separations,energy conversion,and so on.In this paper,we focus on the construction and application of bionic nanochannels based on 2D layer materials.First,a basic understanding of nanochannels based on 2D materials is briefly introduced,we also present the property of the 2D materials and construction strategies of bionic nanochannels.Subsequently,the application of these nanochannels in responsive channels and energy conversion is discussed.The unsolved challenges and prospects of 2D materials-based nanochannels are proposed in the end.

Engineering Mechanical Strong Biomaterials Inspired by Structural Building Blocks in Nature

The intricate multiscale architectures in natural structural building blocks provide many sources of inspiration for the designs of artificial biomaterials.In nature,the assembly of highly ordered molecular crystals and amorphous aggregates often derives from inter-and intra-molecular interactions of biomacromolecules,e.g.,proteinaceous materials.The structural biomaterials derived from the protein self-assembly behave with remarkable mechanical performance.However,there is still a grand challenge to mimic the mechanical properties of natural protein-based biomaterials in a rational design fashion to yield comparable man-made synthetic ensembles.In this review,a brief perspective on current challenges and advances in terms of bioinspired structural materials is presented.We outline a framework for mimicking protein self-assembly of natural building blocks across multiscale and highlight the critical role of synthetic biology and chemical modifications in material biosynthesis.Particularly,we focus on the design and promising applications of protein-based fibers,adhesives,dynamic hydrogels and engineered living materials,in which natural mechanical functions are effectively reproduced.

Bioinspired directional liquid transport induced by the corner effect

Many natural creatures have demonstrated unique abilities in directional liquid transport(DLT)for better adapting to the local environment,which,for a long time,have inspired the material fabrication for applications in microfluidics,self-cleaning,water collection,etc.Recently,DLTs aroused by the corner effect have been witnessed in various natural organisms,where liquid transports/spreads spontaneously along the corner structures in microgrooves,wedges or conical structures driven by micro-/nano-scaled capillary forces without external energy input.Particularly,these DLTs show advantages of ultrahigh speed,continuous proceeding,and/or external controllability.Here,we reviewed recent research advances on the bioinspired DLTs induced by the corner effect,as well as the involved mechanisms and the artificial counterpart materials with various applications.We also introduced some bioinspired materials that are capable of stimulus-responsive DLT under external fields.Finally,we suggested perspectives of the bioinspired DLTs in liquid manipulations.

水凝胶基仿生离子通道及其智能离子传输

离子可控传输是维持众多正常生理活动的重要基础,而实现可控离子传输的关键是生命体系中的各类蛋白质离子通道.受此启发,科研工作者开发了一系列仿生智能离子通道,实现了类似生命体中的可控离子传输.其中,基于水凝胶体系的离子通道由于其空间荷电性和三维互通特性,展现出高离子选择性和高离子通量的优点.同时,水凝胶基离子通道的生物相容性、可形变特性及稳定的离子储存特性,使其成为智能离子传输领域的研究热点之一,该类材料已被广泛应用于离子-电子电路、医疗健康、能源转化与存储以及资源与环境等领域.本文主要从水凝胶基智能离子通道的构筑方法出发,阐述了凝胶内部离子传输机制,并对其在各领域的应用进行了总结,最后对目前水凝胶基离子通道存在的问题及未来发展趋势进行了展望.

Multiscale cellulose-based fireproof and thermal insulation gel materials with water-regulated forms

Different forms of construction materials(e.g.,paints,foams,and boards)dramatically improve the quality of life.With the increasing environmental requirements for buildings,it is necessary to develop a comprehensive sustainable construction material that is flexible in application and exhibits excellent performance,such as fireproofing and thermal insulation.Herein,an adjustable multiform material strategy by water regulation is proposed to meet the needs of comprehensive applications and reduce environmental costs.Multiform gels are constructed based on multiscale cellulose fibers and hollow glass microspheres,with fireproofing and thermal insulation.Unlike traditional materials,this multiscale cellulose-based gel can change forms from dispersion to paste to dough by adjusting its water content,which can realize various construction forms,including paints,foams,and low-density boards according to different scenarios and corresponding needs.

用于皮肤伤口愈合的仿生天然产物的医用粘合剂研究进展

组织粘合剂或伤口敷料可以保护伤口表面并提供有利于伤口愈合的环境。组织粘合剂作为封闭创口或止血的缝合线/钉的替代品,近年来在创伤修复领域受到越来越多的关注。但目前大多数商用组织粘合剂存在粘合强度不足,生物相容性欠佳,功能单一等问题。幸运的是,自然界存在许多天然粘性产物,它们为医用粘合剂的开发提供了新的思路。本文将就天然粘性产物粘合机制及受其影响开发的相关仿生粘合材料进行综述。

贝壳珍珠层及其仿生材料的研究进展

贝壳珍珠层是一种天然的有机-无机层状复合材料,其独特的多尺度、多级次"砖-泥"组装结构赋予其优异的机械性能.受贝壳珍珠层启发,人们已利用不同方法制备了一系列仿生高强超韧层状复合材料,这些材料在航空航天、军事、民用工程及机械等领域表现出广阔的应用前景.本文就贝壳珍珠层的结构及增韧机制和近年来仿贝壳材料的制备方法及其研究进展进行了综述,并提出一些看法和思考.