Smart Materials Research Articles

Correction: Electronic textiles (E-Textiles): types, fabrication methods, and recent strategies to overcome durability challenges (washability & flexibility)

Correction: Electronic textiles (E-Textiles): types, fabrication methods, and recent strategies to overcome durability challenges (washability & flexibility)

Multifunctional Smart Fabrics with Integration of Self-Cleaning, Energy Harvesting, and Thermal Management Properties.

Due to their good wearability, smart fabrics have gradually developed into one of the important components of multifunctional flexible electronics. Nevertheless, function integration is typically accomplished through the intricate stacking of diverse modules, which inevitably compromises comfort and elevates processing complexities. The integration of these discrete functional modules into a unified design for smart fabrics represents a superior solution. Here, we put forward a rational approach to functional integration for the typical challenges of thermal management, energy supply, and surface contamination in smart fabrics. This sandwich-structured multilayer fabric (MLF) is obtained by continuous electrospinning of two layer P(VDF-HFP) fabric and one layer P(VDF-HFP) fabric functionalized with core-shell SiO2/ZnO/ZIF-8 (SZZ) nanoparticles. Specifically, MLFs achieve effective and stable energy harvesting in triboelectric nanogenerators (TENGs) with hydrophobicity and antibacterial properties. Meanwhile, MLFs also have high mid-infrared emissivity and sunlight reflectivity, successfully realizing radiative cooling under different climates, and have been applied in wearing clothing, roof shading, and car covers. This work may contribute to the design and manufacturing of next-generation thermal comfort smart fabrics and wearable electronics, particularly in terms of the rational design of multifunctional devices.

Numerical Analysis of Steel Frame Using Electro-Mechanical Impedance Technique

Nowadays, piezoelectric materials are most widely used in structural health monitoring (SHM) system for nondestructive evaluation. In this paper the damage study using electro-mechanical impedance (EMI) technique, which is nondestructive method of SHM. This paper presents a numerical analysis of four-story steel frame and multiple damages were induced in the steel frame by utilizing smart material like Lead Zirconate Titanate (PZT). A PZT-4 piezoelectric material was embedded in the beam of the frame. The type of damping used in steel frame model was Rayleigh damping. The numerical analysis was done in COMSOL MULTIPHYSICS 6.2 and frequency domain analysis was done, from that admittance values were find out for 30-300KHz frequency range. The real part of the admittance gives conductance values. Then, conductance verses frequency graph was created that will indicate the structural health and performance. Moreover, root mean square deviation (RMSD) index was found out for each case that provides a quantitative measure of deviation.

Starch-based bio-membrane for water purification, biomedical waste, and environmental remediation.

This review article explores the utilization of starch-based materials as smart materials for the removal of dyes and heavy metals from wastewater, highlighting their cost-effectiveness, biodegradability, and biocompatibility. It addresses the critical need for clean water, emphasizing the contamination caused by industrial activities, such as printing, textile, cosmetic, and leather tanning industries. Starch and its derivatives demonstrate significant potential in water purification technology, effectively removing toxicants through hydrogen bonding, electrostatic interactions, and complexation. The review also discusses the application of starch-based materials in the biomedical field, particularly as drug carriers. Starch-based microspheres, hydrogels, nano-spheres, and nano-composites exhibit sustained drug-release properties and are effective in transporting various drugs, including DOX, quercetin, 5-Fluorouracil, glycyrrhizic acid, paclitaxel, tetracycline hydrochloride, amoxicillin, ciprofloxacin, and moxifloxacin. These materials show good antimicrobial activity against a range of pathogens, including C. albicans, E. coli, S. aureus, C. neoformance, B. subtilis, A. niger, A. fumigatus, and A. terreus. While highlighting the significant achievements of starch-based materials, the review also discusses current limitations and areas for future development. Key weaknesses include the need for enhanced adsorption capacities and the challenge of scaling up production for industrial applications. The review concludes by identifying development directions, such as improving functionalization techniques and exploring new applications in water purification and drug delivery systems. This article aims to assist researchers in advancing the field of starch-based materials for environmental and biomedical applications.

Development of Graphene Coated Wearable Electronic Textiles for Biomedical and Health Monitoring Devices

Graphene-based highly, conductive, flexible, washable, and breathable textile electrodes have been developed using the pad-dry-cure method. It is found that the electrical conductivity of the graphenecoated textile electrodes was significantly improved by padding process.

A Flatworm‐Like Hydrogel with Surface Double‐Network Structure for Re‐Programmable Multimode Actuations

AbstractProgrammable stimuli‐responsive hydrogels have rapidly developed for various complex biomimetic actuations, but they commonly can only be programmed once. Herein, a flatworm‐like hydrogel (FLH) with bi‐surface double‐network structure (photothermal‐responsive FLH‐1 and pH‐responsive FLH‐2) has been explored, through UV‐polymerizing sodium poly(methylacrylic‐acid) (PMAA‐Na) and poly (N‐isopropylacrylamide) (PNIPAM) second‐networks on two surfaces of polyacrylamide‐graphene (PAAm‐G) substrate hydrogel first‐network respectively. First, the graphene can both control the thickness of the UV‐polymerized surface second‐network and endow the FLH with high‐efficient photothermal conversion for near‐infrared light (NIR)‐responsive actuation. More importantly, different from common pH‐/photothermal bi‐responsive actuating hydrogels, one FLH can be designed as various original shapes by pH‐responsive FLH‐2, for reprogrammable NIR‐responsive multimode complex actuations via FLH‐1. Finally, the FLH‐1 and FLH‐2 can be strongly integrated together by the interpenetrating structure of flatworm‐like structure between second‐network and first‐network, to endow the FLH with excellent stability for enduring complex deformations. Consequently, the synergy of re‐programmable original shapes via FLH‐2 and NIR‐responsive actuation by FLH‐1, can endow one FLH with multimode actuations for high‐level biomimetic devices. This work can provide a general method by non‐touching design of re‐programmable hydrogel with two stimuli‐responsive layers for multimode complex actuations, which also will inspire explorations of other reprogrammable intelligent materials.

A review on recent trends in smart textiles

Recent advancements in both domestic and international research have considerably enhanced the development of smart fibers and smart textile, which are now being increasingly integrated into the textile industry. Advanced textiles encompass five primary functions; sensors, data processing, actuators, storage and communication. These technologies must be effectively integrated into clothing, ensuring they meet essential requirements like comfort, durability, and resilience to routine maintenance. Designers engaged with traditional textiles might address challenges by integrating smart materials and re-evaluating their design methodologies to leverage the distinctive properties of these advanced materials. This review examines recent developments in Smart Textiles, emphasizing the materials and their recent trends.

A Step Forward for Smart Clothes: Printed Fabric-Based Hybrid Electronics for Wearable Health Monitoring

Smart clothes equipped with flexible sensing systems provide a comfortable means to track health status in real time. Although these sensors are flexible and small, the core signal-processing units still rely on a conventional printed circuit board (PCB), making current health-monitoring devices bulky and inconvenient to wear. In this study, a printed fabric-based hybrid circuit was designed and prepared—with a series of characteristics, such as surface/sectional morphology, electrical properties, and stability—to study its reliability. Furthermore, to verify the function of the fabric-based circuit, simulations and measurements of the circuit, as well as the collection and processing of a normal adult’s electrophysiological signals, were conducted. Under 10,000 stretching and bending cycles with a certain elongation and bending angle, the resistance remained 0.27 Ω/cm and 0.64 Ω/cm, respectively, demonstrating excellent conductivity and reliability. Additionally, the results of the simulation and experiment showed that the circuit can successfully amplify weak electrocardiogram (ECG) signals with a magnification of 1600 times with environmental filtering and 50 Hz of industrial frequency interference. This technology can monitor human electrophysiological signals, such as ECGs, electromyograms (EMGs), and joint motion, providing valuable practical guidance for the unobtrusive monitoring of smart clothes.

Model-based design of a mechanically intelligent shape-morphing structure

Soft robotics has significant interest within the industrial applications due to its advantages in flexibility and adaptability. Nevertheless, its potential is challenged by low stiffness and limited deformability, particularly in large-scale application scenarios such as underwater and offshore engineering. The integration of smart materials and morphing structures presents a promising avenue for enhancing the capabilities of soft robotic systems, especially in large deformation and variations in stiffness. In this study, we propose a multiple smart materials based mechanically intelligent structure devised through a model-based design framework. Specifically, the intelligent structure incorporates smart hydrogel and shape memory polymer (SMP). Employing the finite element method (FEM), we simulated the complex interactions among smart material to analyze the performance characteristics of the intelligent structure. The results demonstrate that, utilizing smart hydrogel and shape memory polymer (SMP) can effectively attain large deformation and exhibit variable stiffness due to the shape memory effect. Besides, the shape-morphing structures exhibit customized behaviours including bending, curling, and elongation, all while reducing reliance on external power sources. In conclusion, utilizing multiple smart materials within the model-based design framework offers an efficient approach for developing mechanically intelligent structure capable of complex deformations and variable stiffness, thereby providing support for underwater or offshore engineering applications.

Nonlinear Control System for Flat Plate Structures Considering Interference Based on Operator Theory and Optimization Method

In recent years, vibration control utilizing smart materials has garnered considerable attention. In this paper, we aim to achieve vibration suppression of a plate structure with a tail-fin shape by employing piezoelectric actuators—one of the smart materials. The plate structure is rigorously modeled based on the Kirchhoff–Love plate theory, while the piezoelectric actuators are formulated in accordance with the Prandtl–Ishlinskii model. This research proposed a control system that addresses the interference effects arising during vibration control by dividing multiple piezoelectric elements into two groups and implementing MIMO control. The efficacy of the proposed control method was validated through simulations and experiments.

The future of wearable health technology: From monitoring to preventive healthcare

Wearable health technology has undergone rapid development, evolving from simple fitness trackers to sophisticated medical devices that provide real-time monitoring and data collection. As these technologies become increasingly integrated into healthcare systems, their potential to shift from reactive treatment to proactive preventive care is gaining attention. This review paper explores the current state of wearable health devices, including the key technologies that enable monitoring and data analysis, and discusses the latest advancements such as AI integration, smart fabrics, and implantable wearables. The paper also delves into the significant role these technologies play in preventive healthcare by enabling continuous monitoring, early disease detection, and personalized health interventions. Furthermore, it addresses the challenges facing wearables, including issues of data accuracy, privacy, and user compliance. Finally, the paper explores future directions and ethical considerations, emphasizing the potential for wearables to reshape healthcare by promoting more accessible, equitable, and preventive healthcare solutions.

A new concept of structural smart fabric activated by shape memory alloys

Abstract This work presents the development, prototyping and validation of a new concept of structure called Structural Smart Fabric (SSF). An SSF is a chainmail fabric composed by interconnected elements, called cells, which can be stiffened by reactive elements, such as those made by Shape Memory Alloy (SMA). Exploiting the shape memory functionality, SSFs are capable of sensing and reacting to external stimuli. Based on this concept, in this study we propose an SSF that integrates SMA wires into a 3D-printed chainmail structure. The shape memory effect of these wires is used as an actuating mechanism that, at high temperature, tightens the adjacent cells together and provides increased structural stiffness. In this study, finite element simulations were initially conducted to enhance the comprehension of the SSF’s mechanical behaviour. The influence of the initial cell spacing on the SSF stiffness and the wire stress profiles was evaluated during bending loading, as well as the evolution of contact pressure profiles between adjacent cells. This numerical approach enabled to tune the design of the SSF prototypes which were successively manufactured using Selective Laser Sintering (SLS) additive manufacturing technology with PA12. After the integration with the SMA wires, the SSF prototypes were tested under a 3-point bending configuration at different temperatures. The results revealed a remarkable increase in structural stiffness at elevated temperatures compared to ambient conditions. This study set the basis for a deeper understanding of SSF's unique capabilities and potential applications in fields where adaptive and responsive structures are required.

Application of Smart Polymer Materialsarts

With the wide application of polymer materials, the performance of ordinary polymer materials gradually cannot meet the shortcomings of use in special environments, such as limited strength, insufficient wear resistance, poor stability and so on. And can not adjust and repair according to changes in the environment. Therefore, the demand for intelligent polymer materials has gradually expanded, and has been applied to a variety of fields after research. This paper introduces the information and application of three kinds of intelligent polymer materials: targeting, shape memory and self-healing. Targeting is mainly used in cancer or other diseases that require precise drug delivery; The characteristics of shape memory can be applied to plaster and surgical sutures in the medical field, and can also be applied to the performance upgrade of traditional manufacturing industry. Self-healing can be used to improve the service life of composite materials by using different methods according to the requirements of different material use scenarios.

Analysis of fatigue degradation process and modelling of an elliptical crack in the locking system of a PET bottle blower

In the dynamic world of Polyethylene Terephthalate (PET) bottle production, ensuring the reliability of blow molding machines is paramount, particularly the locking mechanisms that endure significant cyclic loads during operation. This study investigates the fatigue degradation and crack propagation within the locking system of a two-cavity, 2-liter PET bottle blow molder. By modeling an elliptical crack in the most stressed component, we explore the complex stress distribution and the impact of repeated opening and closing cycles on the system’s integrity. Utilizing advanced finite element analysis (FEA), our research provides a comprehensive understanding of the stress intensity factors and safety margins under varying loading conditions. The results not only enhance predictive maintenance strategies but also offer valuable insights into extending the operational lifespan of these machines, thereby improving safety and reliability in industrial applications. This study opens new avenues in the field of component lifespan prediction. By combining artificial intelligence, machine learning, and innovative materials, it aims to improve the reliability and lifespan of PET blow molders.

SENSORY-FOCUSED FOOTWEAR DESIGN: MERGING ART AND WELL-BEING FOR INDIVIDUALS WITH AUTISM

The application of art in footwear design presents a unique opportunity to enhance the well-being of children and adults with autism by incorporating controlled sensory stimuli. This approach integrates natural elements—like trees, flowers, and serene colors—into shoes, creating a calming sensory experience. Colors such as blue, green, and lilac are strategically chosen for their soothing effects, fostering emotional stability and reducing stress. Research indicates that these hues promote relaxation, with blue associated with tranquility, green symbolizing nature, and lilac evoking spirituality. The texture of the footwear plays a crucial role as well, incorporating raised patterns inspired by natural forms to provide subtle, relaxing tactile stimulation. This allows for pleasant sensory interaction, particularly for individuals sensitive to excessive stimuli. Comfort is further enhanced by the inclusion of soft, non-slip insoles that distribute weight evenly and ensure safety, especially in environments where slips may occur. Recent studies reinforce the importance of creating environments that promote calm and comfort, highlighting innovative solutions that improve quality of life for individuals with sensory challenges. The design of therapeutic gardens and the development of responsive smart clothing illustrate a growing recognition of the benefits of integrating art and nature into everyday experiences. Overall, this focus on empathetic and inclusive design reflects a societal shift toward understanding and addressing the unique needs of those with autism. By prioritizing sensory-friendly features in everyday products, the integration of art into footwear not only enhances aesthetic value but also contributes significantly to emotional and physical well-being, creating a more inclusive world.

The Influence of Halogen Anions on the Color/Fluorescence Dual‐Switching Behaviors of 1,10‐Phenanthroline‐Based Viologen Derivatives

AbstractStimuli‐responsive color/fluorescence dual‐switchable materials have garnered significant attention in displays, sensors, and anti‐counterfeiting. However, current material systems are hampered by the single stimulus‐response and unregulated fluorescence. Viologen derivatives featuring fluorophore as N‐substituent and halogen anions as counteranions not only exhibit responsiveness to both electric and light stimuli but also enable adjustable emission. In this work, we explored the influence of halogen anions on the color/fluorescence dual‐switching behaviors of 1,10‐phenanthroline‐based viologen derivatives. The energy level gaps for phen‐Vio[2Cl−] (2.93 eV), phen‐Vio[2Br−] (2.67 eV), and phen‐Vio[2I−] (2.34 eV) decreased with the decrease of electron affinity of halogen anions (Cl−>Br−>I−), which leads to a sequential improvement in their electrochromic/electrofluorochromic and photochromic/photofluorochromic properties. This work has important guidance for the design and development of smart materials and their optoelectronic devices.

Wearable variable-emittance devices—The future of dynamic personal thermoregulation

Using infrared electrochromism as the strategy to combat the fluctuation of environmental conditions, wearable variable-emittance (WeaVE) devices are able to integrate the functionality of personal thermoregulation and closed-loop control into the future textile, featuring its large tunable range, ultra-low energy consumption, lightweight, and wearability. Recently, this new wearable technology has evolved beyond planar electrochromic cells and is moving closer to woven textiles. To further improve electrochromic performance and wearability, comprehensive progress is necessary from materials science to fabrication techniques. In this Perspective, we elaborate on the mechanisms behind electrochemically active WeaVE devices, analyze how dynamic and fundamental studies may improve the electrochromic performance, and explore the possibility of incorporating nanophotonic designs in the development of this future smart textile through research.

Multifunctional green synthesized silver nanoparticle and polypyrrole-based e-textile for wearable thermoregulation applications

Electronic textiles (e-textiles) build upon existing technologies to develop truly smart textiles: garments that sense, react, and adapt. Thermoregulatory e-textiles are an area of significant interest across the field. Designing e-textiles that satisfy electrical performance and simple construction is a significant challenge. To address these issues, a simple dip-coating and in-situ polymerization method was used to develop the first example of a thermoregulatory e-textile using green synthesized silver nanoparticles (AgNP) and polypyrrole (Ppy), based on the method previously reported (Naysmith, A.; Mian, N.S.; Rana, S. Development of conductive textile fabric using Plackett–Burman optimized green synthesized silver nanoparticles and in situ polymerized polypyrrole. Green Chemistry Letters and Reviews 2023, 16 (1)). This methodology was optimized using a Taguchi statistical design determining the optimal AgNP-Ppy synthesis method to obtain high performance Joule heating e-textiles, novel within the field of e-textiles. Reactant concentration and reaction time had the largest effects on the electrical resistance of subsequent e-textiles. The result is the first example of an e-textile heater based on green synthesized AgNPs. The e-textile demonstrated exceptional Joule heating (120°C), low electrical resistance (37 Ω), resistive temperature sensing behavior (negative TCR = −0.0046), and increased thermal conductivity (19.55 l (Wm−1 K−1)); the strain sensing behavior (gauge factor = −0.07). This work extends knowledge of the development and challenges within e-textile technologies as the field creates the next generation of textiles.

Temperature dependent effect of nano-scale phase change materials on fresh and hardened cement based mortar

One of the smart and innovative materials used to produce environmentally friendly energy-saving concrete is temperature dependent phase change (PCM) materials. In this study, the fresh and hardened concrete properties of the mortars including PCM in different ratios (0%, 2.5%, 5%) were investigated experimentally. Rheological properties such as slump-flow, specific viscosity, and yield stress tests were determined at different temperatures (from 20 to 50 °C). Time-dependent physical, mechanical, and thermal properties such as ultrasound pulse velocity (UPV), electrical resistivity, dynamic modulus of elasticity, compressive and flexural strength, thermogravimetric (TGA), and thermal conductivity tests were carried out. According to the experimental findings, the workability and hardened properties of mortars were decreased by using PCM. However, the rheological properties of fresh mortar change depending on temperature due to PCM absorbing the heat. Therefore, the fresh properties of mortar with PCM can be controlled by temperature. It was also found that the phase change of mortars with PCM can be obtained by measuring the electrical or UPV tests at different temperatures.

Thin-film electrodes of dielectric elastomer-based actuators for an active vibration control system

Precision research and technological equipment, as a rule, is not able to provide its specification characteristics without a high-quality vibration protection system. Active vibration control of an object is provided with the help of an additional source of movement, an actuator. The most promising high accuracy actuators are based on smart materials, such as materials with shape memory, piezoelectric and magnetostrictive materials, electro- and magnetic active fluids and elastomers. Dielectric elastomer is one of the types of electroactive polymers. Actuators based on a dielectric elastomer show high performance in terms of accuracy and speed and operate due to the controllable deformation of the elastomer under the action of a high voltage electric field. The paper provides a comparison of actuators based on sheet and thin film control electrodes. The influence of the quality of the polymer surface and the type of electrodes on the travel range of the actuator and maximum amplitude of vibrations the system can suppress on the basis of a dielectric elastomer is estimated. The formation of the electrode by magnetron sputtering in vacuum makes it possible to create a thin-film layer of copper that covers the elastomer, despite the developed surface. The effect of ion treatment of an elastomer before coating on the quality of the formed electrode is considered. After the ion treatment, the surface of the elastomer acquires a more uniform regular structure. A thin-film electrode layer is formed according to the topology of the elastomer to an accomplished standard.