Photonic crystal （PC） with a periodic dielectric structure exhibits photonic band gap property. It can produce bright and gorgeous structural colors through physical optics upon interaction with incident light. Over the course of evolution， many organisms， such as peacocks， hummingbirds， and insects， have gradually developed complex photonic crystal structures， progressing from one-dimensional nanostructured photonic gratings or multilayers to three-dimensional colloidal crystals， thereby presenting rich and colorful structural colors. Inspired by nature， researchers have developed a series of innovative visual biosensors by fabricating artificial photonic crystal structures and integrating them into biosensor technology. These biosensors， incorporating photonic crystal structures， can visually respond to various stimuli， such as temperature， stress， environmental pH， and small molecules， by altering lattice parameters， dielectric constants， or Bragg diffraction angles through the combination of photonic crystal chromophoric structures and responsive materials. They show great potential in cell mechanics monitoring， drug transport tracking， bionic skin design， wearable bionic materials， and disease prevention and treatment. This review summarizes the application status of photonic crystals in the field of biosensors， including the basic concept of photonic crystal structure color， the photonic crystal structure phenomena in different dimensions in nature， the temperature， mechanics， environmental pH， and molecular response types of photonic crystal structure color biosensors， and their specific applications. Finally， the development prospects of photonic crystal biosensors in the fields of precision medicine， physiological monitoring， and environmental sensing in the future are prospected， emphasizing the importance of ongoing research and improvement of responsive photonic crystal biosensors， to drive advancements in bionic materials and medical science and technology.

Polymer-nanocomposite based flexible and stretchable strain sensors offer portability， simple sensing mechanism， and stable signals， attracting considerable attention in wearable electronics. This paper reviews the research progress of polymer-nanocomposite flexible stretchable strain sensors， with a focus on introducing common types of the properties of polymers and the types of sensing materials. The evaluation of sensing performance mainly includes sensing range and sensitivity. The main factors affecting sensing performance include the selection of polymer materials， the configuration of the conductive network， and the structure design. Although the construction of different types of structures， such as micro-cracks， pore structure， and wavy structure， can contribute to improving the stretchability and sensitivity of the sensor， it is still a challenge to balance its broad detection range and high sensitivity. The main advanced research trends of sensing performance improvements can be oriented towards the selection of highly elastic polymer materials， the optimization of conductive network configuration， and the design of new structures. Polymer-nanocomposite based flexible and stretchable strain sensors will have broad application prospects in human motion detection， personal health monitoring， phonation monitoring， medical monitoring， and futuristic home design.

Flexible phase change composites （FPCCs） are a type of functional material that combines phase change energy storage with flexibility and are widely used in intelligent thermal management，wearable devices，electronic heat dissipation，and other fields. This review expounds the research status of flexible phase change composites，compares and analyzes different methods of their synthesis process，phase change material selection，composite methods and performance regulation；elaborates on the application of flexible phase change composites in intelligent textiles，building energy conservation，electronic equipment heat dissipation and marine platform protection，and looks forward to their advantages in energy storage performance，flexible regulation，high adaptability and future application expansion.

Recombinant collagen hydrogels are ideal materials for promoting wound healing but currently suffer from weak mechanical strength and single functionality，which limit their practical applications. A multifunctional hydrogel with a multi-network structure polymethylacrylamide-acrylic acid/tannic acid/recombinant collagen （MA-AAC/TA/COL） is preparedusing in-situ polymerization. The main raw materials include recombinant collagen，tannic acid，methylacrylamide，and acrylic acid. The microstructure，mechanical properties，swelling performance，adhesive property，self-healing ability，antioxidant activity，antibacterial performance，and biocompatibility of hydrogels with different components are explored. The results show that the multi-network structure design effectively enhances the mechanical properties of the hydrogel. Its maximum tensile strain reaches （250.2±2.7）% and maximum tensile stress is （130±3） kPa. It can withstand 80% compressive deformation without breaking and the maximum compressive strength is （4.23±0.18） MPa. The hydrogel exhibits certain pH sensitivity with different swelling rates under various pH conditions. It has a maximum adhesive strength of （36.27±5.03） kPa on pig skin，a self-healing rate of 67.7% and an in-vitro antioxidant rate of （80.2±0.9）%. It shows good antibacterial effects against E.coli and S.aureus with an antibacterial rate close to 99.99%. Additionally，the hydrogel has low cytotoxicity with a cell survival rate greater than 80%. The MA-AAC/TA/COL hydrogel is expected to serve as a multifunctional wound dressing and find application in the field of wound treatment.

Chronic wounds present significant clinical challenges due to factors such as microbial infection and an imbalanced healing microenvironment， making the healing process difficult and necessitating the development of novel dressings capable of providing both dynamic biological therapy and electrical signal modulation. However， existing hydrogel materials still face considerable difficulties in integrating multiple functionalities， including bioactivity， mechanical flexibility， conductivity， and stimuli-responsive release. To address this， this study proposes a multi-network synergistic design strategy. By combining carboxymethyl agarose （CMA）， sodium alginate （SA）， and polyvinyl alcohol （PVA）， and incorporating multivalent ions Ca²⁺， Mg²⁺， and Zn²⁺， a triple-network hydrogel （CaPSC‑MZ） with ion-conductive and pH-responsive ion-release capabilities has been successfully constructed. The results demonstrate that through the modification of agarose and the multi-network structural design， the CaPSC-MZ hydrogel exhibits an average pore size of approximately 91.47 μm， providing favorable swelling properties （50.07%） and a high water retention capacity （13.13%）. The CaPSC-MZ hydrogel also demonstrates excellent foldability. Moreover， the release of Ca²⁺， Mg²⁺， and Zn²⁺ is enhanced under acidic conditions， achieving a conductivity of up to 24.81 mS/cm. Additionally， CCK-8 experiments confirm that the CaPSC-MZ hydrogel exhibits excellent biocompatibility and promotes cell proliferation. Therefore， this study provides a new material design strategy for developing smart wound dressings with integrated electrical conduction， dynamic therapeutic functionality， and mechanically adaptive properties， showing promising potential in the field of wound management.

This study presents a novel dual-modal flexible sensor that employs an optical-electrical signal decoupling strategy to achieve strain and gas detection， thereby overcoming the limitations of conventional single-modal flexible sensors. The device is constructed using a wrapped-yarn structure， in which polystyrene-butadiene-styrene （SBS） conductive fibers modified with dopamine hydrochloride and polypyrrole （SBS/PDA/PPy） function as the core strain-sensing component， wrapped with tetraphenylethylene-doped thermoplastic polyurethane （TPE-TPU） fibers serve as the gas-responsive component. Experimental results demonstrate that， for gas sensing， the sensor achieves a low detection limit of 59.4 mL/m³ for tetrahydrofuran （THF）， along with a fluorescence quenching efficiency of 78.3% and excellent reversibility and stability. For strain sensing， the device exhibits a broad detection range of 0%-60%， a high gauge factor of 30.455， a rapid response time of 167 ms， and remarkable cycling durability exceeding 1000 cycles. Wearable tests further validate its reliable performance in monitoring human joint motion and respiratory activity. Overall， this work provides a robust strategy for developing multifunctional flexible sensors and demonstrates significant potential for applications in human behavior monitoring and early warning of volatile organic compound gas concentrations in high-risk environments.

Flexible wearable sensors， as a new generation of artificial intelligence devices， have shown great potential for applications in fields such as human health monitoring， human-computer interaction， and artificial intelligence due to their outstanding performance. However， the rapid development of pressure sensors with high compressibility and sensitivity remains a significant challenge. In this study， we successfully polymerize polypyrrole conductive particles on a polyurethane sponge substrate using a one-step method. A highly compressible sponge is prepared economically and efficiently， and a flexible pressure sensor has been successfully assembled. Due to the three-dimensional porous structure of the polyurethane sponge， it exhibits a high sensitivity response （range of pressure≤1.3 kPa， sensitivity=98.73 kPa^-1） and good reproducibility （>2000 compression cycles） under applied pressure. Due to its excellent performance response， the sensors can be placed in different parts of the human body for practical monitoring of physiological and motion signals. In addition， a 5×5 pixel sensing array was prepared for spatial position and pressure analysis， demonstrating the feasibility of sensors in monitoring personal physiological parameters and human-machine interfaces.

As a novel class of smart materials with high flexibility and large deformation，ionic polymer-metal composites （IPMCs） exhibit exceptional electro-actuated deformation characteristics，demonstrating significant potential in flexible robotics，micro-electro-mechanical systems，and biomedical engineering. Nevertheless，their inherent nonlinear dynamic responses and complex kinetic behaviors pose substantial challenges to precise control，severely limiting their deployment in high-performance systems. To overcome this bottleneck，the present study establishes a dynamic response model for high-flexibility，large-deformation IPMCs and optimizes their transfer function based on equivalent-circuit theory. Through an in-depth analysis of the material’s nonlinear properties，a precise constitutive relationship between the physical system and the numerical model is established. To achieve model-order reduction from an infinite-dimensional to a finite-dimensional representation，identification criteria tailored to the large-deformation characteristics of the material are formulated，and three distinct identification methods are employed for systematic identification of its electro-actuated deformation behavior. Results indicate that the refined weighted-iterative algorithm offers markedly superior identification performance，achieving an accuracy exceeding 98%. Additionally，the study reveals that during electro-actuated deformation，the amplitude and phase angle of the material’s dynamic response decrease with increasing resistance but increase with increasing capacitance. The optimized model proposed herein can effectively guide the design and fabrication of IPMCs while enabling high-precision control of their large-deformation behavior. This work provides a solid theoretical foundation for the development of control systems for such materials and holds significant scientific and engineering value for advancing their flexible applications in high-performance domains.

Driven by the “dual-carbon” strategy，which accelerates energy structure transformation，the market demand for high-performance electrochemical energy storage systems has surged significantly. Lithium-ion energy storage devices，leveraging the low atomic weight and low electrode potential of lithium，exhibit substantially higher energy density than other systems and have become a core pillar of modern energy infrastructure. However，their energy density and cycle life still struggle to meet the escalating application requirements，with the irreversible loss of active lithium in anode materials constituting the primary constraint. Prelithiation technology addresses this by introducing an additional lithium source to regulate active lithium precisely，significantly enhancing initial coulombic efficiency and overcoming the application bottleneck of high-capacity materials. Furthermore，it compensates for lithium loss during cycling to extend cycle life and effectively modulates the anode potential window，ensuring stable operation of specialized devices while increasing single-cell energy density. This review systematically summarizes the principles and characteristics of three representative anode prelithiation techniques developed in recent years，including contact prelithiation，electrochemical prelithiation，and chemical prelithiation. It comparatively analyzes the improvements these techniques impart on key energy storage device parameters （initial Coulombic efficiency，cycle life，rate capability，and energy density） based on core operational metrics，including methodology，prelithiation speed and precision，residue control，and active lithium utilization. Considering industrial compatibility，implementation complexity，cost-effectiveness，and economic balance，the review critically assesses the industrial potential and existing challenges of each technique，summarizing realized industrial application cases. From an engineering application perspective，it synthesizes the technical advantages and disadvantages，outlines future development trends and research directions to address current limitations，and aims to provide theoretical guidance for commercial technology advancement.

A solid oxide fuel cell （SOFC） is a green and efficient electrochemical device for energy conversion. Due to the use of solid ceramics as electrolyte materials， it needs to work in a high-temperature environment of 600-1000 ℃. The high-temperature environment can accelerate the aging of equipment materials， resulting in the rapid decline of battery performance. SOFC technology operating at intermediate- and low-temperatures can improve the startup speed of the system， enhance the durability of the equipment， and expand the scope of equipment selection. Therefore， the development of intermediate and low-temperature SOFC technology is crucial to achieve its commercial application. Since charge transfer and oxygen exchange reactions in solid electrolytes are thermally activated processes， reducing the operating temperature of SOFCs will elevate the ohmic polarization of the electrolyte and exacerbate the polarization loss of the electrode， thereby compromising the actual output power of the SOFC system. In recent years， studies on intermediate- and low-temperature SOFC technology have primarily focused on optimizing the microstructure and chemical composition of electrode and electrolyte materials. In this review， the research progress on the SOFC key materials， including both electrode and electrolyte materials， is systematically summarized. Furthermore， the future design strategies and development directions of these key SOFC materials are prospected.