Self-healing Concept Research Articles

Self-Healing concept for musculoskeletal pain management: An evidence-based review

Международные рекомендации обычно включают комплементарные и интегративные подходы к лечению мышечно-скелетной боли. Это улучшает общее самочувствие при одновременном снижении зависимости от традиционных фармакологических методов лечения и связанного с ними риска побочных эффектов.

Self-Healing concept for musculoskeletal pain management: An evidence-based review

Medzinárodné smernice bežne integrujú komplementárne a integratívne prístupy do manažmentu muskuloskeletálnej bolesti, čo zlepšuje celkovú kvalitu života a súčasne znižuje závislosť na konvenčnej farmakologickej liečbe a súvisiace riziko vedľajších účinkov.

Self-Healing concept for musculoskeletal pain management: An evidence-based review

As diretrizes internacionais costumam integrar abordagens complementares e integrativas na gestão da dor músculo-esquelética. Isto melhora o bem-estar geral ao mesmo tempo que reduz a dependência de tratamentos farmacológicos convencionais e o risco associado de efeitos indesejáveis.

Investigating Cracks Prevention in Concrete Utilizing the Self-Healing Concept of Bacillus Subtilis Bacteria

Concrete is the most common and widely used construction material. In the concrete structure, cracks are sometimes produced due to external loads and other reasons. Due to cracks, the concrete begins to take compression loads in the structure; therefore, repairing such cracks is essential. Different methods are used to repair the cracks in concrete, but in this thesis, we are working on bacteria base self-healing of cracks in concrete. For self-healing concrete different types of bacteria are used but we are using the bacteria named Bacillus subtilis in concrete. By adding bacillus subtilis and calcium lactate we find that the concrete becomes more strengthened and self-healed as compared to normal concrete. There are two methods of adding the bacteria to concrete which is direct adding an encapsulation method. We followed the direct application method in this method the bacteria is added directly to concrete. The test results show that the bacterial concrete has higher compression strength and self-healing concrete.

Review on Self-Healing Thermal Barrier Coatings for Space Applications

Abstract The demand for reusable space transportation systems is increasing, which leads to the need for higher-performance, reliable rocket engines at the lowest possible cost. The steep thermal gradient in the combustion chamber of rocket engines is catered by certain cooling mechanisms. In the case of reusable rocket engines, a progressive deformation and thinning of the cooling passage wall during engine operation is encountered because of the plastic ratcheting after numerous thermal cycles. This phenomenon may lead to the catastrophic failure of the engine when in operation and it also limits the number of operation cycles, adding cost. Thermal barrier coating (TBC) was successfully employed initially, and the functionally graded coatings were subsequently employed. However, the spallation of TBCs exists upon repeated thermal cycles. It is felt as necessary to induct the self-healing concept in such applications to enhance the number of thermal cycles. Various researchers have investigated crack-healing behavior of ceramic materials in recent years. This article provides a comprehensive analysis on the findings in the self-healing TBC and discusses future perspectives in this research area. This article mainly focusses on self-healing systems based on molybdenum disilicide (MoSi2)/MoSi2(B) with yttria partially stabilized zirconia and MCrAlY. In addition, the isothermal kinetics of MoSi2/MoSi2B and the formation of zircon are also discussed. The methodology of encapsulating the self-healing particles in order to avoid premature oxidation of MoSi2 self-healing particles is also discussed.

Would Self-healing be economically justifiable on LV networks?

Self-healing (SH) functions have been studied through pilots on E-REDESMedium Voltage (MV) network with positive results. The natural next step would be to apply the SH concept to Low Voltage (LV) networks. However, LV and MV networks have distinct characteristics (criticality, capillarity, complexity, energy distributed by km of network, technology, etc.). The economic criteria that justify SH on MV network are not applicable to LV networks. This article presents and discusses several challenges related to implement SH to LV networks and other aspects to be considered. The SH concept is discussed when applied to LV network. Also, the advantages that operational management can achieve with this concept available on daily operations. Other big challenge is the technology evolution that must occur on sensors and, most of all, actuators, to accommodate automatisms and to be remotely monitored and controlled. Also, a telecommunication solution needs to be established to support the real-time interaction between all the components. Last, but not least, the economic aspect. How and when can an extra cost be justifiable on a network that didn't felt the necessity to be automated for so many years. Should we start to consider it now? Two use-cases are proposed.

Self-Healing: A Concept for Musculoskeletal Body Pain Management - Scientific Evidence and Mode of Action.

Traditionally, musculoskeletal pain management has focused on the use of conventional treatments to relieve pain. However, multi-modal integrative medicine including alternative/complementary treatments is becoming more widely used and integrated into treatment guidelines around the world. The uptake of this approach varies according to country, with generally a higher uptake in developed countries and in females aged more than 40 years. Integral to the concept described here, is that the body has an innate ability to self-heal, which can be optimized by the use of integrative medical strategies. Stress triggers for acute or recurring musculoskeletal pain are diverse and can range from physical to psychological. The mechanism by which the body responds to triggers and initiates the self-healing processes is complex, but five body networks or processes are thought to be integral: the nervous system, microcirculation/vasodilation, immune modulation, muscular relaxation/contraction and psychological balance. Multi-modal integrative medicine approaches include nutritional/dietary modification, postural/muscular training exercises, and cognitive behavioral mind/body techniques. This article will review the self-healing concept and provide plausible scientific evidence where available.

Meta-Analysis and Machine Learning Models to Optimize the Efficiency of Self-Healing Capacity of Cementitious Material.

Concrete and cement-based materials inherently possess an autogenous self-healing capacity. Despite the huge amount of literature on the topic, self-healing concepts still fail to consistently enter design strategies able to effectively quantify their benefits on structural performance. This study aims to develop quantitative relationships through statistical models and artificial neural network (ANN) by establishing a correlation between the mix proportions, exposure type and time, and width of the initial crack against suitably defined self-healing indices (SHI), quantifying the recovery of material performance. Furthermore, it is intended to pave the way towards consistent incorporation of self-healing concepts into durability-based design approaches for reinforced concrete structures, aimed at quantifying, with reliable confidence, the benefits in terms of slower degradation of the structural performance and extension of the service lifespan. It has been observed that the exposure type, crack width and presence of healing stimulators such as crystalline admixtures has the most significant effect on enhancing SHI and hence self-healing efficiency. However, other parameters, such as the amount of fibers and Supplementary Cementitious Materials have less impact on the autogenous self-healing. The study proposes, through suitably built design charts and ANN analysis, a straightforward input–output model to quickly predict and evaluate, and hence “design”, the self-healing efficiency of cement-based materials.

Self-healing materials for space applications: overview of present development and major limitations

In the last decade, self-healing materials have become extremely appealing for the field of space applications, due to their technological evolution and the consequent possibility of designing space systems and structures able to repair autonomously after damage arising from impacts with micrometeoroids and orbital debris, from accidental contact with sharp objects, from structural fatigue or simply due to material aging. The integration of these novel materials in the design of spacecraft structures would result in increased reliability and safety leading to longer operational life and missions. Such concepts will bring a decisive boost enabling new mission scenario for the establishment of new orbital stations, settlement on the Moon and human exploration of Mars.The proposed review aims at presenting the newest and most promising self-healing materials and associated technologies for space application, along with the issues related to their current technological limitations in combination with the effect of the space environment. An introductory part about the outlooks and challenges of space exploration and the self-healing concept is followed by a brief description of the space environment and its possible effects on the performance of materials. Self-healing materials are then analysed in detail, moving from the general intrinsic and extrinsic categories down to the specific mechanisms.

Evaluation of Methodologies for Assessing Self-Healing Performance of Concrete with Mineral Expansive Agents: An Interlaboratory Study.

Self-healing concrete has the potential to optimise traditional design approaches; however, commercial uptake requires the ability to harmonize against standardized frameworks. Within EU SARCOS COST Action, different interlaboratory tests were executed on different self-healing techniques. This paper reports on the evaluation of the effectiveness of proposed experimental methodologies suited for self-healing concrete with expansive mineral additions. Concrete prisms and discs with MgO-based healing agents were produced and precracked. Water absorption and water flow tests were executed over a healing period spanning 6 months to assess the sealing efficiency, and the crack width reduction with time was monitored. High variability was reported for both reference (REF) and healing-addition (ADD) series affecting the reproducibility of cracking. However, within each lab, the crack width creation was repeatable. ADD reported larger crack widths. The latter influenced the observed healing making direct comparisons across labs prone to errors. Water absorption tests highlighted were susceptible to application errors. Concurrently, the potential of water flow tests as a facile method for assessment of healing performance was shown across all labs. Overall, the importance of repeatability and reproducibility of testing methods is highlighted in providing a sound basis for incorporation of self-healing concepts in practical applications.

A new generation self-healing composite materials

Self-healing is a certain type of unique physicochemical property, by which the material can be able to repair automatically the damage or fracture part of our tissue due to accident and used successfully at the time of operation. This damage may be due to accidents or by ageing processes. This self-healing concept is a blessing to medical science. Now-a-days extensive work is carried out with the self-healing materials. The mechanism of self-healing is of two kinds, the first one is autonomic systems, which requires no stimulus and the second one is non-autonomic system, which requires external stimulus such as heat or light for repairing damaged tissue. Self-healing materials behaves like elastomers and have a number of important applications in commercial and industrial sectors. The self-healing composite act as a significant healing agent and create an external trigger by initiating the process. Self-healing material is a novel sustainable material and can be successfully applied in many fields especially in tissue engineering.

A Review of Self-healing Metals: Fundamentals, Design Principles and Performance

Self-healing metals possess the capability to autonomously repair structural damage during service. While self-healing concepts remain challenging to be realized in metals and metallic systems due to the small atomic volume of the mobile atoms, the slow diffusion unless at high temperatures and the strong isotropic metallic bonds, the scientific interest has increased sharply and promising progress is obtained. This article provides a comprehensive and updated review on the developments and limitations associated with the various modes of potentially healable damage induced in metals and alloys, i.e., stress-induced damage, irradiation-induced damage in bulk materials and contact damage in corrosion protective coatings. The spontaneous intrinsic healing mechanisms not requiring external assistance other than the material operating at the right temperature and an assisted healing mechanism with external intervention are reviewed. Promising strategies to achieve self-healing in metals are identified. Finally, we give some prospects for future research directions in self-healing metals.

Semi-alive architecture “from healing to self-healing in architecture”

Buildings are exposed to external factors, time factor, and usage during their operational life that their sustainability, toughness, and shape get affected negatively. Those factors also reduce the reliability of building materials and technologies used in them since buildings are lifeless being and they don’t possess the properties of living beings. For decades, scientists tried to transform the properties of living beings to various science fields such as computing, architecture, and others. One of the most important properties is the ability of living beings to heal from damage and to resist external factors. The concept of healing in architecture refers to developing maintenance and preservation techniques but they remain traditional and don’t evolve to the concept of sustainability. Therefore, more attention has been given to making buildings possess self-healing property and making them sustainable so that they last for the most possible period while reducing maintenance costs and preserving them. Hence, this study is concerned with “the problem of the absence of a complete knowledgeable vision of the self-healing concept in architecture and that of transferring the properties of this concept from living beings to architecture”, while the object of the study “is to transform buildings from being dead to being semi-alive those can specify and fix damage by themselves, so they can renew themselves or resist external factors”. In order to achieve its objective, this study have taken the concept of healing in general and particularity in architecture form various angles, from the effects of healing on the user or the environment and also the effect on the building itself, to recommending traditional methods of maintenance, renovation, and rehabilitation to achieve healing. Also, the study was concerned with self-healing concept in general and how to achieve it in architecture with the aid of technological advancements via surveillance systems of the structural health, developments in building materials, self-assembly, and renewal and how it affected the designers’ design strategy and philosophy. A comparison was also made between healing and self-healing methodologies in order to achieve sustainability in architecture before finishing the study with conclusions.

Self‐repairing hardware architecture for safety‐critical cyber‐physical‐systems

Digital embedded systems in safety-critical cyber-physical-systems (CPSs) require high levels of resilience and robustness against different fault classes. In recent years, self-healing concepts based on biological physiology have received attention for the design and implementation of reliable systems. However, many of these approaches have not been architected from the outset with safety in mind, nor have they been targeted for the safety-related automation industry where the significant need exists. This study presents a new self-healing hardware architecture inspired by integrating biological concepts, fault tolerance techniques, and IEC 61131-3 operational schematics to facilitate adaption in automation and critical infrastructure. The proposed architecture is organised in two levels: the critical functions layer used for providing the intended service of the application and the healing layer that continuously monitors the correct execution of that application and generates health syndromes to heal any failure occurrence inside the functions layer. Finally, two industrial applications have been mapped on this architecture to date, and the authors believe the nexus of its concepts can positively impact the next generation of critical CPSs in industrial automation.

Self-healing hardware systems: A review

Self-healing is increasingly becoming a promising approach to designing reliable digital systems, and it refers to the ability of a system to detect faults or failures and fix them through healing or repairing. Digital systems with architecture for self-healing are expected to compensate faults. However, there are a few research challenges that need to be overcome before self-healing becomes a mainstream approach. For example, current self-healing techniques face challenges such as scalability, reliability, area overhead, and mapping. This paper explains the self-healing concept and investigates the self-healing approaches related to digital design in the literature. It gives a general overview of the topic and explains levels of abstraction at which self-healing can be used: hardware level, application level, and system level. The paper presents multiple related works at each level of abstraction. In the faulted phase, different types of faults and fault detection methods are described. For the evaluation of a self-healing technique, this paper presents the parameters which can be used to evaluate a self-healing method. These parameters are redundancy rate, the maximum ratio of repair, self-healing time consumption, reliability, and area overhead. The paper also presents a comparison between previous works of self-healing in terms of evaluation techniques. Implementations using VHDL and ISE Xilinx Vertex-5 for self-healing on Embryonic Hardware (EmHW) and Network-on-Chip (NoC) are also presented. The simulation results show the contribution of self-healing to improve system reliability and mean time to failure.

On the Development of a Space Satellite Mirror with Intrinsic Self-Healing Properties

In the aerospace industry the demand for very strong and light components is a permanent objective and for this matter composite materials began to be used at large scales in construction of space structures. The presence of micrometeoroids and orbital debris in space, particularly in the lower earth orbit, presents a continuous hazard to orbiting satellites, spacecraft, and the International Space Station. Among the 8700 objects larger than 10 cm in Earth Orbits, only about 6% are operational satellites and the remainder is space debris. Likewise, a major challenge for space missions is the material selection due to the fact that in space materials present a higher degradation rate and they are subjected to wear and structural damage, especially when facing extreme environmental conditions. In this paper, a self-healing concept embedded into a Carbon Fiber Reinforced Polymer (CFRP) composite parabolic satellite mirror is under development at COMOTI Research & Development Institute for Gas Turbines. The goal of the research is to provide a material that increases the operational life of satellites in Low Earth Orbit (LEO). The work addresses two different but interconnected fields, material science for developing a multifunctional composite material having an embedded self-healing system and aerospace field for developing a new, lightweight structure. The self-healing system under study consists in a blend of microcapsules containing variations of dicyclopentadiene (DCPD) monomers, 5-Vinyl-2-norbornene (VNB), 5-Ethylidene-2-norbornene (5E2N or ENB) and ethylene glycol dicyclopentenyl ether methacrylate (EGDP).

Demonstration of self-healing barrier films for vacuum insulation panels

This article presents the demonstration of a rapid self-healing system for barrier films of vacuum insulation panels (VIPs). The proposed self-healing films can improve the durability of VIPs by in-situ remediation of film defects. The self-healing concept has seen limited applications in buildings, and the current work is the first proposed application to VIPs. VIPs can achieve an order-of-magnitude lower thermal conductivity than traditional foam and fibrous building insulations. The key to the ultra-low thermal conductivity of VIPs is an evacuated core that is fully-encapsulated within impermeable barrier films. Evacuation of the core eliminates the gas conductivity, which is the dominant contributor to heat transfer in traditional insulation materials. Thus, the integrity of the VIP barrier films is critical. The proposed self-healing system can seal accidental cuts and punctures to the barrier films to maintain their impermeability and, hence, the low conductivity of VIPs.Here, the proof-of-principle of a two-part chemical reaction-based self-healing system is presented, including the evaluations of reaction kinetics using chemical-structure analysis and time-dependent viscosity change, and demonstration of self-healing performance via puncture tests in a vacuum pump apparatus. Multiple chemical combinations of epoxies and curing agents were investigated with respect to reaction kinetics and chemical stability. Epon 8111 as an epoxy and poly(ethyelenimine) (PEI) as a curing agent were identified as the optimum chemicals with a curing time of 22 s as evaluated by an agitating stirrer experiment. 1H nuclear magnetic resonance (NMR) spectra analysis identified the curing reaction occurring mainly via the Michael amine-acrylate addition. The measured time-dependent viscosity change of diluted Epon 8111 and PEI solutions agreed well with a gelation model of typical epoxy curing kinetics, which predicted a very fast reaction rate for the undiluted chemicals. Finally, puncture tests of small-scale film specimens containing Epon 8111 and PEI in a vacuum pump system demonstrated that the self-healing reaction happens very rapidly and the healed films maintain the system vacuum.

Taking a microfluidic approach to the production of self-healing construction materials

Taking a microfluidic approach to the production of self-healing construction materials

Flexible aromatic disulfide monomers for high-performance self-healable linear and cross-linked poly(urethane-urea) coatings

Implementation of the self-healing concept in coatings is challenging because they have to combine mechanical strength and chain mobility. This challenge is addressed in this work by studying the effect of the polymer microstructure on the mechanical properties and self-healing ability of waterborne poly(urethane-urea) coatings containing aromatic disulfide dynamic bonds. The structural modifications studied are the concentration and flexibility of the aromatic disulfide units and the effect of cross-linking. The effects and limits of these structural changes on the mechanical properties of the polymers and their healability were determined via a combination of DMA measurements, tensile tests, and rheological and scratch closure experiments. It was found that the flexibility of the disulfide unit was key to develop more efficient self-healing materials which offer the necessary molecular mobility for self-healing while simultaneously maintaining a level of mechanical strength that are essential for coating applications.

Mechanical behavior of aeronautical composites containing self-healing microcapsules

Purpose Over the last decades, self-healing materials based on polymers are attracting increasing interest due to their potential for detecting and “autonomically” healing damage. The use of embedded self-healing microcapsules represents one of the most popular self-healing concepts. Yet, extensive investigations are still needed to convince on the efficiency of the above concept. The paper aims to discuss these issues. Design/methodology/approach In the present work, the effect of embedded self-healing microcapsules on the ILSS behavior of carbon fiber reinforced composite materials has been studied. Moreover, the self-healing efficiency has been assessed. The results of the mechanical tests were discussed supported by scanning electron microscope (SEM) as well as by Attenuated Total Reflection–Fourier-transform infrared spectroscopy (ATR–FTIR) analyses. Findings The results indicate a general trend of a degraded mechanical behavior of the enhanced materials, as the microcapsules exhibit a non-uniform dispersion and form agglomerations which act as internal defects. A remarkable value of the self-healing efficiency has been found for materials with limited damage, e.g. matrix micro-cracks. However, for significant damage, in terms of large matrix cracks and delaminations as well as fiber breakages, the self-healing efficiency is limited. Originality/value The results obtained by SEM analysis as well as by ATR–FTIR spectroscopy constitute a strong indication that the self-healing mechanism has been activated. However, further investigation should be conducted in order to provide definite evidence.