Smart Composite Materials Research Articles

Mechanical properties and damage mechanism of SMAHC laminates

Abstract The combination of smart materials and composite materials to achieve lightweight and intelligent structures has been an important research direction in recent years. In this paper, a three-dimensional woven hybrid shape memory alloy (SMA actuator) is modularly implanted into a composite laminate to prepare a SMA hybrid composite (SMAHC) laminate. The orthogonal test was designed with the three variables of SMA actuator modular implantation position, SMA pre-strain and SMA number. According to the orthogonal test results and finite element results, the influence of the three variables on the stiffness before heating, the stiffness change rate after heating and the strength of SMAHC laminates was studied. According to the test index, the influence of the three variables on the results was further evaluated. The results show that the implantation position has the greatest influence on the mechanical properties of SMAHC laminates, followed by SMA pre-strain, and the number of SMA has the least influence. The location and form of damage of SMAHC laminates are further summarized, and the bending damage mechanism of SMAHC laminates is analyzed.

Optimizing the grasping behavior of a soft robot's gripper

AbstractIn this study, smart composite materials based on 4D printing technology were used to determine the grasping ability of four‐claw gripper of soft robot. First, fused deposition modeling (FDM) is used to prepare polylactic acid (PLA) strips on the surface of a rectangular bamboo substrate to create a single‐claw gripper for a smart composite soft robot, while using stimulus (heat) to deform and recover its original shape. Here, the authors first evaluate the deformation and recovery angle of the single‐claw gripper of the smart composite soft robot, as well as various processing parameters such as heating temperature and time. This study then used FDM to print PLA ribbons on cross‐shaped bamboo sheets to design the four‐claw gripper of soft robot and its gripper technology was actuation type. Then, the four‐claw gripper of soft robot was used to grab the table tennis ball to test its grasping ability. Finally, four processing parameters (width of claw, pitch of PLA ribbon, heating temperature, and heating time) were applied to determine the grasping ability of the four‐claw gripper of soft robot. The optimal processing parameters for the grasping ability of the four‐claw gripper of soft robot were width of claw of 20.2 mm, pitch of PLA ribbon of 1 mm, heating temperature of 200°C, and the heating time of 15 s. The authors also applied the operation window of two processing parameters to discuss the success of the grasping ability of the four‐claw gripper of soft robot. The innovation of this study is the use of PLA/bamboo composite materials as the four‐claw gripper of soft robot and these materials are cheap, easy to obtain, and can be recycled naturally. This study uses a simple thermal stimulus to enable the four‐claw gripper of soft robot to easily grasp irregular objects.Highlights The innovative composite material of polylactic acid and bamboo fabricated by 3D printing. Width of claw and heating temperature are the key factors on grasping ability. Operating window of grasping ability appears on four‐claw gripper of soft robot.

Anchoring mycelium on CNTs to make strong and smart self-regenerative composite materials

How to develop new recycled composite materials to meet the growing global demand for sustainable materials is of great interest. In this paper, by leveraging the growth of mycelium to anchor CNTs, the self-regenerative mycelium-CNTs composite materials (MCCs) are created. It demonstrates good strength (∼30 MPa), self-healing (restore ∼98 % original strength), and self-sensing properties. Finally, a human care-computer interaction device is developed to demonstrate the application of this technology. Our manufacturing process utilizes the autonomous growth of living cells grown in in vitro cultures to produce regenerable living composites that do not require harsh chemical processing and polluting exhaust emissions. The final mechanical properties are comparable to commercial polymer plastics, and their functional properties can be further tuned by introducing nanoparticles.

Drop-on-Demand 3D Printing of Programable Magnetic Composites for Soft Robotics

Soft robotics have become increasingly popular as a versatile alternative to traditional robotics. Magnetic composite materials, which respond to external magnetic fields, have attracted significant interest in this field due to their programmable two-way actuation and shape-morphing capabilities. Additive manufacturing (AM), also known as 3D printing, allows for the incorporation of different functional composite materials to create active components for soft robotic systems. However, current AM methods have limitations, especially when it comes to printing smart composite materials with high functional material content. This is a key requirement for enhancing responsiveness to external stimuli. Commonly used AM methods for smart magnetic composites, such as direct ink writing (DIW), confront challenges in achieving discontinuous printing, and enabling multi-material control at the voxel level, while some AM techniques are not suitable for producing composite materials. To address these limitations, we employed high-viscosity drop-on-demand (DoD) jetting and developed versatile programmable magnetic composites filled with micron-sized hard magnetic particles. This method bridges the gap between conventional ink-jetting and DIW, which require inks with viscosities at opposite ends of the spectrum. This high-viscosity DoD jetting enables continuous, discontinuous, and non-contact printing, making it a versatile and effective method for printing functional magnetic composites even with micron-sized fillers. Furthermore, we demonstrated stable magnetic domain programming and two-way shape-morphing actuations of printed structures for soft robotics. In summary, our work highlights high-viscosity DoD jetting as a promising method for printing functional magnetic composites and other similar materials for a wide range of applications.

Smart Composite Materials with Self-Healing Properties: A Review on Design and Applications.

Research on self-healing materials spans multiple academic disciplines and employs a variety of methodologies. Nature has been a major source of inspiration for developing self-healing materials and will likely continue to inspire innovative ideas in this field. This review article covers the principles of self-healing mechanisms, focusing on both autonomous and non-autonomous procedures. It explores both intrinsic and extrinsic self-healing abilities by considering their components, structures, and design. Additionally, a detailed analysis of the application of these materials across various sectors is provided, including aerospace, automotive, marine, energy, medical and healthcare, military, and construction. Finally, the review paper highlights the advancements in encapsulation technologies for microcapsules, their thermal stability, their mechanical properties, and the compatibility of healing agents with the matrix, which play a crucial role in the effectiveness of self-healing processes.

Experimental investigation on flexural performance of concrete beams strengthened with SMA-GFRP-ECC smart composite materials

The structural performance improvement of concrete members is by far a crucial theoretical issue for engineers, and the development of modern smart and composite materials makes it possible to gradually enhance the durability design of the concrete structure. In this study, six beams of the same size and reinforcement ratio, the proposed composite beam (SMA-GFRP-ECC) and five comparative beams (RC, R-ECC, SS-ECC, GFRP-ECC, SMA-ECC), were designed and tested under low-cycle unidirectional cyclic loading and unloading conditions. The energy dissipation capacity, displacement ductility, residual deformation, and self-repairing performance of each concrete beam were evaluated. Afterward, a concise calculation model for the studied composite beam is deduced and developed based on the existing relevant constitutive models and concrete assumptions. The test results indicate that compared with RC beams, the composite reinforced ECC beams show obvious multi-cracking and smaller crack width during the loading process and have good bending ductility. The innovative SMA-GFRP-ECC beam is capable of a high bearing capacity, ductility, and damage self-repairing. The new proposed beam has more than 80% of the maximum crack width recovery capacity during unloading. Hence, the proposed SMA-GFRP-ECC beam is a rather good first attempt of strengthened beams, combining the advantages of SMA, GFRP, and ECC.

Synthetic oil gels with organoclays in the formulation of magnetorheological fluids

Magnetorheological fluids (MRF) are smart composite materials that, under an external magnetic field, show a reversible solid-liquid transition in less than 10 ms. This study aimed to evaluate which organoclays would jellify a synthetic oil for the formulation of MRF. Three dispersant additives for carbonyl iron powder were evaluated. Fifteen different gelling additives from four clay families, bentonites, hectorites, montmorillonites, and mixed mineral thixotropes (MMT), were dispersed in oil only, keeping the same concentration, without iron particles. The gels were then tested through amplitude and frequency sweeps in oscillatory rheometry to evaluate their viscoelastic behavior. The thixotropy of the gels was measured through the “three-interval” test in a rheometer. After selecting the best gelling additive to prepare the MRF, three dispersing additives had their rheology evaluated to determine the best magnetorheological effect and redispersibility after 1 year of sample preparation. In the linear viscoelastic region, all MMT clays resulted in a weak viscoelastic gel (G′∼100 to 300 Pa and G″∼30 to 50 Pa). Some of the bentonite clays jellified, and others did not. The best organoclays were montmorillonites and hectorites, which formed consistent viscoelastic gels (G′∼1 to 5 kPa and G″∼70 to 250 Pa). The best organoclay presented a yield stress σ0 = (42 ± 3) Pa, a storage modulus G′ = (2690 ± 201) Pa, and a cohesive energy density (CED) = 98 mJ/m3, and it was selected to explore the rheology of MRF with three dispersant additives: octan-1-ol, octan-1-amine, and L-α-Phosphatidylcholine. All the MRFs were prepared using carbonyl iron powder HS (BASF SE) in oil gels and with the same organoclay. All three dispersant additives showed a thixotropic recovery above 100% in the three-interval test. Regarding the redispersibility after 1 year, the MRF formulations with octan-1-amine and lecithin were reproved, as they reached normal force peaks of 19 and 24 N, while the work was 28 and 415 mJ, respectively. The best MRF was formulated with octan-1-ol, and resulted in a normal force of 0.33 N and 3.4 mJ at 35 mm of vane penetration. Therefore, we conclude that the MRF with octan-1-ol and montmorillonite #6 showed a better balance between thixotropy, MR effect, and, above all, good redispersibility.

Advanced multifunctional Co/N co-doped carbon foam-based phase change materials for wearable thermal management

To cope with the complex and changeable extreme environments, extending multifunctionality is crucial for potable smart wearable composite phase change materials (PCMs). Herein, we developed advanced Co/N co-doped carbon foam-based multifunctional “five-in-one” composite PCMs integrating dual-temperature thermal management, light-triggered heating, waterproof, flame retardant, and microwave absorption through high-temperature calcination of melamine foam@ZIF67 and melting encapsulation of paraffin wax (PW). Benefiting from the strong full-spectrum absorption, fast photon and phonon transport, and local surface plasmon resonance effect, our designed foam-based composite PCMs exhibited an ultrahigh photothermal conversion efficiency of 95.17 %. More importantly, foam-based composite PCMs demonstrated excellent thermal management, structural stability and thermal storage stability after undergoing 300 heating–cooling cycles. Furthermore, foam-based composite PCMs showed superior microwave absorption (RLmin = -57.93 dB), good flame retardancy and satisfactory hydrophobicity (contact angle > 100°). Thus, our developed multifunctional foam-based composite PCMs provide great potential for personalized thermal management and anti-radiation smart wearables even in harsh environments (e.g., rain, snow, sweat, fire, extreme cold, extreme heat and electromagnetic interference), creating a versatile platform for smart wearable light-triggered phase change heater with on-demand properties.

Efficient Chlorostannate Modification of Magnetite Nanoparticles for Their Biofunctionalization.

Magnetite nanoparticles (MNPs) are highly favored materials for a wide range of applications, from smart composite materials and biosensors to targeted drug delivery. These multifunctional applications typically require the biofunctional coating of MNPs that involves various conjugation techniques to form stable MNP-biomolecule complexes. In this study, a cost-effective method is developed for the chlorostannate modification of MNP surfaces that provides efficient one-step conjugation with biomolecules. The proposed method was validated using MNPs obtained via an optimized co-precipitation technique that included the use of degassed water, argon atmosphere, and the pre-filtering of FeCl2 and FeCl3 solutions followed by MNP surface modification using stannous chloride. The resulting chlorostannated nanoparticles were comprehensively characterized, and their efficiency was compared with both carboxylate-modified and unmodified MNPs. The biorecognition performance of MNPs was verified via magnetic immunochromatography. Mouse monoclonal antibodies to folic acid served as model biomolecules conjugated with the MNP to produce nanobioconjugates, while folic acid-gelatin conjugates were immobilized on the test lines of immunochromatography lateral flow test strips. The specific trapping of the obtained nanobioconjugates via antibody-antigen interactions was registered via the highly sensitive magnetic particle quantification technique. The developed chlorostannate modification of MNPs is a versatile, rapid, and convenient tool for creating multifunctional nanobioconjugates with applications that span in vitro diagnostics, magnetic separation, and potential in vivo uses.

Shape-Stabilized PEGylated Silica Aerogel-Composite as an Energy Saving Building Material.

Balancing thermal and visual comfort in buildings necessitates effective insulation to counteract heat loss and gain, especially with temperature variances. One promising approach is to combine phase change materials, such as poly(ethylene glycol) (PEG), with high-performance insulators like silica aerogel (Siag). To bolster opto-thermal performance in building envelopes, we introduce a smart insulation composite material through PEG integration, i.e., PEGalyation with Siag. Central to this thermal behavior is the PEG's phase change properties, which foster a shape-stabilized framework with Siag through their porous confinement. Preliminary observations indicate notable capabilities of obstructing near-infrared light while preserving satisfactory visible transparency. An optimized Siag@PEG composite with 5% loading of PEG has the visible range transmission of ∼92%, a decrease of ∼72% in thermal conductivity which is lower than pure glass and PEG, leading to a temperature dependent switchable hydrophobic to hydrophilic wettability characteristics. As a prototype window, the thermal performance evaluation of the synthesized composite, through experimental and computational studies, shows a decrease in indoor temperature of ∼20% with a higher temperature difference of ∼20 °C between outdoor and indoor weather conditions. This lightweight composite can act as sponge media to fill inside the double-paned window and for retrofitting existing glazing to boost the energy efficiency of buildings with facile manufacturing and scalability.

Toward the development of a new smart composite structure based on piezoelectric polymer and flax fiber materials: Manufacturing and experimental characterization

Although technologies and processes for creating smart composite structures have been established, significant limitations still necessitate additional research to overcome. Indeed, numerous studies have highlighted the challenges of embedding active elements, often leading to compromises in the structural integrity of smart composite materials. In contrast, this study introduces a novel perspective, offering innovative insights and valuable contributions to the existing knowledge. The primary contribution of this study lies in addressing the critical need for the seamless integration of active materials within composite structures. To demonstrate this, our study considers the potential integration of Polyvinylidene Fluoride (PVDF), a polymer-based piezoelectric material, with pre-impregnated unidirectional flax fibers to produce a smart composite structure. The consolidation molding process was adopted to manufacture the smart composite samples for investigations. Experimental analysis were then considered to evaluate the influence of the embedded PVDF film on the mechanical performance of the structure and to assess the resulting functional properties. X-ray micro-computed tomography and an additional strength-of-material test approach, Interlaminar Shear Strength (ILSS), were performed to explore the impact of the insertion on the integrity of the laminate structure. On the other hand, we conducted vibration tests to assess the electromechanical properties. The tomography results reveal void elimination in the edges of the active material insert, which could be attributed to the choice of thin film materials. Moreover, the ILSS results highlight the minimal impact of PVDF material on mechanical performance, showcasing a mere 0.69% degradation of the material strength. These results are comparable to the recently reported works but with an appreciable margin of improvement. The vibration test response demonstrates the ability of the embedded piezoelectric material to generate voltage, which validates our integration procedure. The smart composite material’s sensitivity to ambient vibrations and its power generation potential show promise for sensing and energy harvesting.

Experimental Investigation of Cumulative Damage and Self-Healing Properties of Smart Cementitious Composite under Continuous Compression Load.

This study investigated the effect of sustained loading on the cumulative damage of a newly developed smart cement-based self-healing composite material (SMA-ECC). SMA-ECC is composed of engineered cementitious composite (ECC) and shape memory alloy (SMA) fibers. A uniaxial compressive test with five predefined loading levels (0%, 30%, 40%, 50%, and 60% of compressive strength) was conducted on SMA-ECC hollow-cylindrical specimens and ECC control hollow-cylindrical specimens. The cumulative damage was mainly determined by changes in the total water absorption of different groups of specimens during three different periods (not loaded, at a predefined loading level, and after unloading). A normalized water content index was proposed to couple the effects of self-healing, sustained loading, and cumulative damage. The test results indicate that the cumulative water absorption of SMA-ECC was 35% lower than that of ECC, which may indicate less irreparable damage. In addition, the self-healing ability of SMA-ECC specimens under different compression load levels was evaluated through normalized water content analysis. SMA-ECC exhibited a 100% repair rate at load levels of 30% and 40%. At a higher load level of 60%, the repair rate of SMA-ECC was 76%. These results collectively emphasize the significant impermeability and self-healing performance of SMA-ECC after unloading.

Composition, Structures, and Preparation of Smart Composite Materials Based on Polyurethane and Modified Silicon Carbide Particles with Controllable Characteristics and Kinetics of the Shape Memory Effect

Composition, Structures, and Preparation of Smart Composite Materials Based on Polyurethane and Modified Silicon Carbide Particles with Controllable Characteristics and Kinetics of the Shape Memory Effect

Numerical Simulation of Magnetoelectric Composite for Power Supply of Small Biomedical Devices

This paper introduces a comparative numerical modeling and simulation study of a smart composite material combining piezoelectric ceramics Terfenol-D/GFRP/PZT-5H and Terfenol-D/PZT-5H. The remarkable combination of high output voltage coefficients and substantial power output positions this composite as an ideal candidate for energy transduction applications, particularly in wireless power devices within the field of biomedical applications. Additionally, we explored the potential of PZT-5A to evaluate the feasibility of modeling both piezoelectric and magnetostrictive self-sensing responses under the influence of applied stress. This numerical investigation was complemented by a series of mechanical tests aimed at characterizing the piezoelectric and magnetostrictive responses, as well as the material's mechanical strength.The results obtained demonstrate the successful accomplishment of active vibration control through the development of a smart self-sensing composite material. This composite harnesses the piezoelectric properties of PZT-5A ceramics and the magnetostrictive properties of Terfenol-D. The remarkable combination of a high output voltage coefficient and substantial power output positions this composite as an exceptional candidate for energy transduction applications, particularly in the realm of biomedical devices requiring wireless power. Specifically, Terfenol-D/GFRP/PZT-5H composite materials show promise for enhancing wireless powering solutions in biomedical applications

Опережающая подготовка специалистов для космического строительства

This article considers the issue of training designers and technicians for the creation of orbital and planetary structures within the group of specialties 24.00.00 “Aviation and rocket and space technology”. This work is relevant due to the expanding plans for the construction of national and international space stations in the Earth and the Moon orbits, and the construction of bases on the surface of celestial bodies. It is assumed that the exploration of celestial bodies can begin before the end of this decade with the bases created on the surface of the Moon. It is noted that the implementation of these projects must involve the modular principle, the use of robotic mechanisms, smart composite materials, natural resources of celestial bodies and solar energy. Several international master’s degree programs in space construction and architecture are described in brief. As an example, the key features of the new master’s degree curriculum in the field of training 24.04.01 “Rocket complexes and Cosmonautics” developed at the Department of SM-13 “Rocket and Space Composite Structures” at the Bauman Moscow State Technical University are given. A number of new disciplines, new for an aerospace university have been included in the curriculum for the master’s degree graduate to form the necessary competencies in the field of space construction.

Solution to the traffic problems of long and deep water straits–smart submerged floating tunnel and its research

Submerged floating tunnel (SFT) is a new type of structure across long and deep water straits and waterways with good application prospects. The structure is different from the traditional large-span bridges and immersed tunnels, which can effectively avoid difficulty under the construction of bridges foundation in deep water straits and channel, the high cost of large span bridge, influence of typhoons and heavy fog et al. severe weather on the vehicle driving on the bridges, a series of technical problems confronted under the construction of immersed tunnel or tunnel excavation in complex marine geology and the deep sea and risk control and so on. This paper, in the light of the characteristics of submerged floating tunnels and the requirements of marine deep water environment, discusses some of technical challenges faced in the designing and building the SFT, points out that it is necessary to systematically study the design and load condition, the smart composite material and shape optimization, the calculation theory and method for analyzing the structural behavior, the structure safety evaluation, construction methods and key technology, and engineering risk analysis, smart monitoring, evaluation and control, code or guide for design and construction of SFT. It lays foundation for design, construction and engineering risk analysis, etc. of submerged floating tunnel across the long and deep waterways in the future.

4D printing of multi-stimuli responsive rigid smart composite materials with self-healing ability

Smart materials combined with favourable mechanical strength, high self-healing efficiency, and multi-stimuli responsive ability show promising applications in diverse fields, such as biotechnology and minimally invasive devices. However, the mutually exclusive conflicts among these properties make it challenging to balance them simultaneously. In this study, we proposed a multi-stimuli responsive rigid smart material based on modularization scheme for the first time, which can respond to temperature and magnetic stimulation, are designed and successfully prepared by 4D printing of shape memory epoxy resin, Fe3O4@GO, and self-healing microcapsules. The resultant smart materials show excellent tensile strength (17.2 MPa), high self-healing efficiency (91.2%) at room temperature, and rapid magnetic-stimuli responsive (15 s). It is worth noting that the recovery rate of fractured samples can be still up to 82.0% after three times fracture repairs, suggesting their strong self-healing ability at room temperature. More importantly, the obtained materials can be further exploited for a wide variety of applications, such as smart space deformable structures, temperature sensors, and grippers, exhibiting enormous potential for the development of next-generation smart structural components.

Collective transport and reconfigurable assembly of nematic colloids by light-driven cooperative molecular reorientations.

Nanomotors in nature have inspired scientists to design synthetic molecular motors to drive the motion of microscale objects by cooperative action. Light-driven molecular motors have been synthesized, but using their cooperative reorganization to control the collective transport of colloids and to realize the reconfiguration of colloidal assembly remains a challenge. In this work, topological vortices are imprinted in the monolayers of azobenzene molecules which further interface with nematic liquid crystals (LCs). The light-driven cooperative reorientations of the azobenzene molecules induce the collective motion of LC molecules and thus the spatiotemporal evolutions of the nematic disclination networks which are defined by the controlled patterns of vortices. Continuum simulations provide physical insight into the morphology change of the disclination networks. When microcolloids are dispersed in the LC medium, the colloidal assembly is not only transported and reconfigured by the collective change of the disclination lines but also controlled by the elastic energy landscape defined by the predesigned orientational patterns. The collective transport and reconfiguration of colloidal assemblies can also be programmed by manipulating the irradiated polarization. This work opens opportunities to design programmable colloidal machines and smart composite materials.

Evaluation of conductive smart composite polymeric materials for potential applicationsin structural health monitoring and strain detection

The presented work collects results from the evaluation of electrical response to mechanical deformation and formation of defects presented by different polymeric based composite materials with potential for applications in Structural Health Monitoring and Strain Detection. With the aim of showing the variety of key materials in sectors like civil aviation, wind energy, automotive or railway that present this ability, specimens of very different nature have been analyzed: a) thermoplastic commercial 3D printing filaments loaded with carbonic fillers; b) epoxy resin loaded with Carbon Nanotubes and c) long carbon fiber reinforced resin composite. Measurements of electrical properties of these materials were taken to evaluate their capability to detect the presence of structural defects of different sizes as well as its spatial location. On the other hand, simultaneous measurements of electrical resistivity and mechanical strain during tensile tests were performed to analyze the potential of materials as strain detectors. All composites studied have shown a positive response (modification of electrical performance) to external mechanical stimulus: induced damage and deformations.Graphical

Long period grating fibre sensor for detection of impurities infesting smart polymer composites

An analysis of using Long Period Grating Fibre Sensors (LPGFS) as detectors of Smart Composite Polymer Material (SCPM) impurity infestation is presented. The analysis is performed by using a self-developed simulation package. The investigated LPGFS is operated as mounted into a self-interference (SILPG) setup embedded in polymer matrix. The LPGFS constitutes the feedback loop of an automation system. The simulation results are compared with experimental ones and a good agreement between the two kinds of data being observed. The analysis is aiming to an optimized design of this type of sensors for accomplishing the proposed task which means enlarged applications range in aeronautics, industry, medicine and defence of SCPM.