Materials Science

From the Ground Up-Materials Science in Singapore.

The Cambridge Engineering Selector (CES) is a tool that focuses on material, process, and shape combinations of product design. The Resource Consumption Model (RCM) is a tool that focuses on production process resources, resource costs, production volume, production capacity, and manufacturing cycle time. Both tools help identify viable manufacturing process alternatives to meet stated manufacturing objectives.

Today supply chain management has become one of the crucial factors for gaining and sustaining a competitive advantage. Enterprises that can more effectively manage their supply chain network have a higher likelihood of success in the marketplace. To this end, companies need not only make the “make” or “buy” decisions but also differentiate across potential suppliers in order to improve operational performance, and hence, supplier selection is one of the key decisions aiding effective supply chain management. Many studies have also pointed out that the integration of product and supply chain is a key factor for profitability and efficiency. However, prior studies mostly address supply chain performance after the creation of a new product; and only a few studies discuss when and how to incorporate supply chain decisions during product design. In the studies that cover product design, product family and product platform concepts are presented as enabling vehicles for mass customization, which require a considerable investment, and hence might be out of reach for small to medium size enterprises (SME). Accordingly, there is a need to develop a methodology that can consider manufacturability and supply chain issues at the product design stage. This paper presents a graph theory based optimization methodology to tackle this problem. The supplier selection issue is considered by evaluating its impact on both engineering (e.g., process planning) and operational performance (e.g., cost and time), which are then aggregated as the supply chain performance at the conceptual design stage. A case study in the bicycle industry demonstrates the advantages of this methodology. The synchronized structure of the supply chain and the product design results in simultaneous optimization of both design and supply chain decisions during the early design stages.

An overview of the effect of stirrer design on the mechanical properties of Aluminium Alloy Matrix Composites fabricated by stir casting

Fetal therapies have become available for a restricted number of life-threatening clinical conditions. Harnessing tissue engineering for prenatal applications has not been widely pursued even though isolating cells from fetal and extraembryonic tissues has been routinely done for years. The objectives of this thesis were twofold: i) the development of materials based and tissue engineering based strategies to prevent iatrogenic preterm prelabour rupture of fetal membranes (iPPROM) after diagnostic or therapeutic interventions into the amniotic cavity and ii) the generation of tissue substitutes from patient derived fetal cells, which can be employed for prenatal or perinanal transplantation to restore or replace defective tissues. For the prevention of iPPROM, mussel-mimetic tissue adhesive (mussel glue) a biomaterial which was recently described to not compromise cell viability and to have good tissue sealing capability was compared to fibrin glue. In this in vivo study we assessed whether in a mid-gestational rabbit model punctured fetal membranes could be efficiently sealed with mussel glue. Mussel glue showed comparable in vivo performance to fibrin glue in sealing fetal membranes though no apparent healing of the membranes could be observed in any of the samples. The limited ability of naturally derived scaffolds to promote fetal membrane healing inspired the engineering of synthetic plugging material with specifically tailored biological and mechanical properties which could activate the cells in the amnion and induce a healing response. In this thesis the modularly designed biomimetic poly(ethylene glycol) (PEG)-based hydrogel platform (called TG-PEG from here on) was used together with fetal cells to demonstrate that upon presentation of appropriate biological cues in 3D tissue mimicking environment, mesenchymal progenitor cells from amnion can be mobilized, induced to proliferate and supported in maintaining their native extracellular matrix production, thus creating a suitable environment for healing to take place. These data provide the basis for future engineering of materials with defined mechanical and biochemical properties and the ability to present migration and proliferation inducing factors, namely PDGF, bFGF, or EGF which could be key in resolving the clinical problem of iPPROM and allowing the field of fetal surgery to move forward. Cleft palate, where the bones of the palatal halves fail to fuse properly, is one of the most common birth defects. Tissue engineering has been envisioned as a treatment option but current approaches have been limited by the lack of i) appropriate autologous cell sources and ii) structural organization and vascularization. Tissue engineering of cleft palates using of autologous amniocentesis-derived and thus ethically unproblematic fetal amniotic fluid cells (AFCs) could be done parallel to the ongoing pregnancy with living reconstruction material being ready when the child is born. We describe using TG-PEG hydrogels to first evaluate 3D osteogenic differentiation of AFCs and creation of vascular structures from AFC derived endothelial cells (enAFC) and undifferentiated AFC either in random or organized channel cocultures in vitro and in vivo. Next, these approaches were combined in an osteogenic matrix with a channel perfused with enAFC and finally the integration and functional properties of these fetal bone constructs was tested in ectopic mouse model.

. Production efficiency as well as the reduction of energy consumption and waste are the main drivers for the improvement of large-scale production in chemical industry. In addition, the demand for new processes – these days especially related to the chemical energy conversion as basis for the Energiewende – are additional triggers for innovation. Catalysis, well recognized by the public e.g. in form of the 3-way automobile catalyst, plays an important role for about 90% of all processes in chemical industry. The development of new and improved catalysts is a challenge for chemists – as is the search for new structural materials for mechanical engineers. Due to the often-necessary noble and thus expensive metals (e.g. palladium) in many catalysts, structural and chemical function have been developed separately in the two communities. Recent progress in catalytically active materials allows replacing expensive noble metals in selected catalytic processes by significant cheaper elements [1]. This offers the new perspective to combine structural and chemical functionality by innovative materials. Within this area, intermetallic compounds with their peculiar combination of crystal and electronic structure [2], represent an interesting class of materials to address this vision as will be shown in the contribution.

Mechanical Properties: Key Topics in Materials Science and Engineering provides a practical overview of tensile testing and what it reveals about the strength of materials and the load-carrying capabilities of structural components. The book is organized in two sections roughly equal in length. The first section is a tutorial on mechanical properties and behaviors expressed in the form of load-displacement and stress-strain curves. The section that follows furthers the learning process by guiding readers through a series of real-world problems and their respective solutions. The information in this book is particularly well suited for early-career engineers, especially those involved in product design.

Collaborative innovation, in which multiple companies try to incorporate content generated by consumers into new product development, is becoming increasingly popular. The fact that overconfidence usually increases with more data means that companies integrating large amounts of consumer-generated content in collaborative innovation have a strong tendency to be overconfident. We study the effects associated with overconfidence in collaborative innovation, where overconfidence is defined as a decision maker’s cognitive bias that leads to an overestimation of the precision of an uncertain event. In our collaborative innovation model, an online shopping platform collects and assimilates content (such as online reviews) generated by consumers to generate a product design and then sells that design to the manufacturer, after which the manufacturer produces a corresponding new product and sets a retail price. In this article, we mainly focus on how overconfidence impacts the product design strategy, pricing strategies, and decision makers’ equilibrium profit levels. We demonstrate that overconfidence can be a positive force for collaborative innovation and even lead to a win-win-win situation for the platform, manufacturer, and consumer. We show that overconfidence can make the platform change its product design strategy from aesthetic-oriented in the unbiased scenario to functionality-oriented in the biased scenario. Furthermore, we show that each of the two product design strategies has its own scope of application; neither is universally dominant.

Addition of fillers to polymers has long been used as a strategy to enhance the properties of polymers. In the last two decades, however, a class of materials termed as "polymer nanocomposites" (PNC) has evolved to refer to blends of polymers and inorganic fillers in which the inorganic component has one or more dimensions below 100 nm.1-3 Examples of such materials include mixtures of a variety of homopolymers and multicomponent polymers blended with fillers such as clays, nanotubes, Fullerenes, polyhedral oligomeric silsesquioxanes (POSS), nanoscopic silica particles, and so forth.2-7 Initial interest and research in such materials arose from the significant property enhancements reported for extremely low loadings of nanofillers. These reports fueled intense research into the mechanical, electrical, barrier, and fire retardancy properties of PNCs and have led to some notable commercial technologies utilizing PNCs.1, 8-10 More recent efforts have expanded the above class of studies and materials by examining the properties of nanocomposites involving polymer blends and block copolymers, where the potential to create multifunctional materials possessing novel electrical, magnetic, and optical properties have been reported.11, 12 However, despite the scale of intense research on PNCs, much of the initial promise of PNCs has not yet borne out. In this viewpoint article, I present an (admittedly) personal perspective of some of the issues confronting the field of PNCs, focusing especially on the opportunities by which theory, modeling, and computer simulations from polymer physics may aid in realizing the full potential of PNCs. Many of the common nanofillers used in PNCs are unfortunately characterized by strong van der waals interparticle attractions, which promote their agglomeration.13 Moreover, the effective interactions between nanofillers are also influenced by the polymer-filler interactions, and if the latter are unfavorable, it leads to conditions conducive to the aggregation of the fillers. Aggregation and clustering of the fillers typically leads to a significant reduction in the interfacial contact between the fillers and the polymer and hence a deterioration of the property enhancements that can be attained in PNCs. Consequently, achieving stable, dispersed configurations of nanofillers in the polymer matrix is a prime requirement to realize the full property potential of PNCs. Many experimental strategies have been explo-red to overcome the above challenge.14 These have ranged from using polymer-filler combinations, which are known to exhibit favorable affinities to functionalizing the fillers by self-assembling surfactant and grafting polymers to promote favorable polymer-filler interactions (and provide a steric barrier against agglomeration). Also, successful strategies using external fields to promote nonequilibrium dispersion of the nanofiller have been demonstrated.15 From a theoretical perspective, the outstanding question confronting the design of such strategies is "For specified combination of matrix polymer(s), filler(s), the functionalizing moieties and/or external fields, can we predict the equilibrium and nonequilibrium structural characteristics of the PNC dispersion?" Anisotropy of fillers: Most of the PNCs explored for applications involve filler particles such as clays, carbon nanotubes, nanofibers, and so forth, which exhibit considerable shape anisotropy. Indeed, such fillers prove most suitable for exploiting significant polymer-filler interfacial contact at even extremely low loadings of the filler. In contrast, very few of the aforementioned theories and simulations deal with the phase behavior and structure of mixtures of anisotropic fillers dispersed in single and multicomponent polymers.27-29 The rich literature of colloidal physics suggests that the equilibrium characteristics of anisotropic colloids can be expected to be significantly different and richer compared with their isotropic counterparts.30 Moreover, situations combining anisotropic fillers with multicomponent polymers such as block copolymers can be expected to reveal a rich interplay between polymer self-assembly and colloidal phase behavior. It will be of significant interest to PNC research to translate some of the theoretical advances achieved in the context of spherical fillers to the corresponding situations involving anisotropic fillers. Role of Functionalization: As mentioned earlier, functionalization of the fillers is a common strategy to overcome the issue of agglomeration of fillers. However, in much of the existing theories, the role of functionalization is treated either empirically as a modified polymer-filler interaction18, 23 or in more detailed formalism as a modification of the effective polymer-mediated potentials between the fillers. The first approach can be deemed reasonable for small oligomeric or surfactant-like functionalizers, but suffers from the drawback that it leaves open the question of the relationship between the polymer-filler interaction and the physicochemical properties of the functionalizing group. The second approach has typically been effected for the situation of grafted polymer functionalizers.31 It is, however, a pairwise interaction approach that works only for the homogeneous phase of the polymer matrix and in addition neglects multibody effects, which may become important when either long grafting polymers or higher concentrations of fillers are used. Overall, it would be desirable to develop a suite of simulations and/or modeling tools that, similar to the nongrafted case, can obviate such assumptions while still being able to predict the structure of the PNC dispersion. Structure under nonequilibrium and external field conditions: Despite the best experimental strategies, nonequilibrium effects resulting from filler aggregation and/or external fields are bound to remain important for many applications of PNCs, especially for situations involving anisotropic fillers. Some unresolved questions include: "How does the structure of a PNC dispersion evolve upon dispersing the fillers in the polymer matrix?," "Can quantities such as the fractal dimension and cluster size distributions be predicted for specified polymer-filler combinations?," "How does externally applied shear, electric, and magnetic fields (and combinations thereof) impact upon the nonequilibrium state of the dispersion?" Although computer simulations may shed light on some of the relevant issues, the time and length scales, which can be probed by such means may not necessarily overlap with experimental regimes, and there is a need for development of appropriate theoretical models to address pertinent issues. There have been some notable theoretical advances in this regard in the context of colloidal science,32, 33 and a preliminary assessment of their applicability to the field of PNCs would be extremely beneficial. However, issues unique to PNCs, such as the significant anisotropy of the fillers, potentially long-ranged interparticle interactions (mediated by the polymers), the dynamical and rheological response of the polymer matrix, are expected to prove important and provide fertile and challenging areas for theoretical research. Detailed structural characteristics: Many experimental studies of the mechanical, electrical, and rheological behavior of PNCs have suggested an intimate connection between enhanced macroscopic properties and the percolation behavior of the fillers.10, 34-36 Although such features can be directly extracted in computer simulations, existing theoretical frameworks mostly concern with the phase behavior and/or structural features at a pair correlation level. It may be of interest to the PNC experimental community to develop a theoretical framework, which can predict the the influence of different interactions, functionalization, and external fields upon more detailed structural characteristics such as the percolation characteristics37, 38 fractal and cluster dimensions of the fillers in the polymer matrix. Connection to atomistic details: Much of the above discussion focused on some open questions in the context of structure of PNCs as examined from a "coarse-grained" polymer physics perspective. Although such efforts are valuable for providing design guidelines, deducing mechanistic underpinnings and suggesting new experimental strategies, questions involving the detailed chemistry of the filler, polymer and functional groups cannot typically be answered in such frameworks. This situation is compounded by the fact that much of the coarse-grained modeling of PNCs use potentials and interaction parameters, which cannot also be directly determined from experimental measurements. The latter contrasts with the analogous situation in multicomponent polymer melts and solutions where experimental solubility measurements provide direct information on the parameters used in the corresponding coarse-grained theories.39 Addressing this shortcoming in the context of PNCs requires the development of efficient computer simulation tools and methodologies, which can render the connection between the chemistry of the components and the coarse-grained parameters more quantitative. The research field of "coarse-graining methodologies" is undergoing intense development in the context of simple and polymeric fluids.40-42 Although some notable "multiscale" efforts have also occurred in the context of PNCs,43, 44 much work remains to be done in surmounting the time, length scale challenges accompanying the interactions, structure, and properties of PNCs. Detailed structural information: Much of the aforementioned macroscopic theories were developed for model structural representations such as random or completely aligned dispersions while ignoring PNC specific features such as aggregation and/or complex structural arrangement of the fillers. Consequently, it is not surprising that such ideal models cannot quantitatively predict the properties of PNCs. One potential area for future research is the development of macroscopic models capable of accommodating detailed structural information, such as experimentally obtainable pair correlation functions of the fillers or cluster sizes and fractal dimension of aggregates, while rendering quantitative predictions regarding the macroscopic properties of PNCs. This area has recently seen some notable advances, especially arising from numerical continuum mechanical approaches.47-49 It may be envisioned that the results of such efforts can be used to guide the refinement of classical models to accommodate the PNC specific features. Interfacial effects: An important feature that distinguishes PNCs from traditional composites is the presence of significant amounts of polymer-filler interfaces and its influence upon the macroscopic properties. To highlight the resulting issues, I point out the status with respect to the "simpler" situation of polymer films supported on a solid substrate. In such contexts, experiments have clearly demonstrated that the polymer-surface interactions can lead to properties for the polymer layer, which are in general markedly different from that of the bulk polymeric material.50 Moreover, for properties such as glass transition temperatures,51 aging dynamics,52, 53 and elastic moduli,54 the interfacial effects have been shown to persist to extremely long length scales relative to the physical dimensions of the polymer. In the context of properties that exhibit only a short ranged interfacial effects (such as solubility of penetrants and mechanical properties), the aforementioned approaches may suffice to accommodate the influence of polymer-filler interfaces upon macroscopic properties. However, to endow a predictive value to theories, quantitative connections between the physicochemical polymer-filler interactions and the properties of the interfacial layer (or the parameters in the boundary conditions) in such models needs to be established. Although computer simulations may aid in this effort, in many cases, new formalisms may be necessary to discern quantities such as "local" mechanical properties,55 "local" conductivities, "local" penetrant diffusivities, and so forth, in such efforts. Once the connections between polymer-filler interactions and the interfacial properties are firmly established, "homogenization theories" similar to that used for the macroscopic properties of composites and dispersed media may be pursued. However, such approaches still need to be augmented to account for the possibility of complex structural arrangement of the fillers (an issue discussed earlier) and the overlap of interfacial layers which may consequently arise. As discussed earlier, some interfacial properties (such as the glass transition temperatures) are known to display long ranged variations influenced by the surface of the fillers, and in such cases, boundary condition and/or three-phase model approaches are likely to prove inadequate for capturing the influence of polymer-filler interfaces upon the macroscopic properties of the system. Refining the existing models to account for such properties represents an extremely challenging task, because in many cases there is a lack of understanding of the physics underlying such long ranged variations in polymer thin films. Moving to PNCs brings even more complications, such as the possibility for overlap of interfacial layers arising from different particles (such overlaps become very likely for long-ranged effects), leading to significant multibody interaction effects. Overall, this is an area for which the directions of theoretical modeling are far less clear (to me), suggesting that radically new ideas may be necessary to make progress in understanding and predicting the properties of polymer thin films and PNCs. The above represents an opinionated selection of some of the open questions confronting theoretical modeling of polymer nanocomposite systems. While active research is in progress in a number of the above-mentioned areas, successful fruition in many of the issues requires a confluence of ideas from different fields, viz., colloid and polymer physics, statistical and continuum mechanics, modeling and simulation approaches, and most importantly, experiments and theories. While technology and experiments are likely to provide more focus to the issues and theoretical efforts, progress in the above delineated issues is expected to have significant fundamental implications for many related areas of polymer and colloidal science, and may also potentially lead to uses and applications of PNCs above and beyond what has been realized or even dreamed about. This research program on polymer nanocomposites has been graciously supported by research grants from the National Science Foundation, American Chemical Society, Air Force Research Laboratories, Robert A. Welch Foundation, and the US Army Research Office under grant W911NF-07-1-0268. The author thanks Dr. Victor Pryamitsyn for useful comments which helped to shape the ideas expressed in this viewpoint. The author also acknowledges Profs. Glenn Fredrickson, Kenneth Schweizer, John Torkelson, Peter Green, Donald Paul, Jack Douglas, Sanat Kumar, Richard Vaia, and Ramanan Krishnamoorti for many discussions over the years while patiently educating him on the issues in polymer nanocomposites.

This review article presents a comprehensive analysis of recent advancements in sound insulating materials, focusing on the characterization of material types and their properties from 2015 to 2024. It examined the application of various natural and synthetic materials, including fibrous, porous, composite, polymeric, and advanced materials, in architectural and environmental acoustics. A systematic search in the Scopus database identified relevant articles that were classified according to the material types and their inherent properties. The analysis covered key aspects such as thermal, mechanical, chemical, and physical characteristics, and their impact on sound insulation performance. Unlike previous studies that focused on classic materials or single aspects, this review used analytical and database tools to identify recent research trends. This review highlights the development of advanced and sustainable materials for noise reduction that address challenges in both building acoustics and environmental sound pollution.

The ability for a product developer to successfully launch useful products is tied to the company’s product design strategies. Due to the complexity of perception and expectations on new product design from customers and the diverse perspectives of the product developer, any approaches without systematically analyzing these complex criteria to assess decision making on product design strategies are therefore deemed as inappropriate. A systematic approach to determine appropriate product design strategies based on the attributes of product design and customer expectations should thus be considered. This research focuses on the investigation of shape formulation process using evolutionary grammars (EG) and non-linear product design analysis with Kano model to refine product design strategies. Through the strategic integration of evolutionary grammars and Kano model, the complex effects on the evolutionary design process and product design strategies are revealed. In order to demonstrate the viability of the approach, experiments are described and a comparison analysis on three EG-Kano reference models is performed. Upon determining the appropriate EG-Kano reference model, the product developer can refine the product design strategies to suit the targeted market.

The research aims to produce, model, and optimise the mechanical properties of novel composite material through a structured multidisciplinary approach. The primary objective is to combine materials science, mechanical engineering, and statistical concepts to ensure Design for Manufacturability (DFM) from the industrial perspective. More specifically, the article is intended to determine the optimal mixture components and predictive model of Al-Si alloy with Al2O3 by accommodating multi-responses that enable DFM. The study adopted ASTM standards to prepare and test the novel composite material. Additionally, the Mixture Design of Experiment (DOE) approach was used to design the experimentation and subsequent analysis. In addition, microstructural images, Cox Response Trace plot, and Response Optimiser plot are effectively utilised to draw robust inferences. For multi-response modelling and optimisation, the composite material’s mechanical properties, like impact strength, hardness, density, and tensile strength, are considered. The study determines that innovative composite material will yield better results when Al-Alloy is 94.65 wt% and Al2O3 is 5.35 wt% from a multi-responses perspective. Further, it provides predictive models with a high level of predictability. Besides, the research shows that novel composite material has better mechanical properties from a practical perspective. The article not only provides the mechanical properties of a new class of material but also shows the effective utilisation of material science and statistical concepts to develop the novel material in a structured manner. This composite material can be used as a replacement for various parts of automobiles and aircraft. Additionally, researchers can use the article’s modelling and optimisation approach as a paradigm to create durable composite materials.

In the world of business competition, entrepreneurs are demanded to be able to respond and act quickly to face increasingly fierce business competition within the scope of one location. Entrepreneurs are expected to be able to compete healthily and competitively to create the most exciting innovations to maintain their loyalty. Each entrepreneur will make every effort to influence the buyer's decision by consumers so that they are interested in the products they market. This explanatory research uses primary data collected from respondents to be processed through SPSS, data and statistical application. In this study, the objects are the relationship between price, product design, location, store atmosphere, and consumer decisions. The subject of this research is a Culinary Cafe located in Malang City. The sampling technique used is purposive sampling, and the sample obtained is 100 respondents. The data analysis used is descriptive statistics, and multiple regression is used to test the hypothesis in this study. The results show that the variables of price, product design, and location significantly affect purchase decisions, while store atmosphere has no significant effect on purchase decisions. And from the simultaneous test results, the four independent variables together affect purchase decisions at Culinary Cafes in Malang City. Companies can use the implications of this research to make decisions to attract consumers to make purchases.

This study aims to determine the effect of Product Quality, Product Design, Green Product, Brand Image, and Purchase Decision variables. The results of the research on the t test indicate that the Product Quality variable (X1) has no significant effect on purchasing decisions with a significance value of 0.432 > 0.05 and a t count value 1.98498 < t table 4.020; Product Design variable (X2) has no significant effect on purchasing decisions with a significance value of 0.931 > 0.05 and a t-count value of 1.98498 < t table 4.020; Green Product variable (X3) has no significant effect on purchasing decisions with a significance value of 0.270 > 0.05 and a t-count value of 1.98498 < t table 4.020; Brand Image variable (X4) has no significant effect on purchasing decisions with a significance value of 0.451 > 0.05 and a t-count value of 1.98498 < t table 4.020. Based on the results of the F test, the variables of product quality, product design, Green Products and Brand Image simultaneously do not have a positive effect on the purchasing decision variables, because the significance value is 0.681 > 0.05.
 Keywords : Product Quality, Product Design, Green Product, Brand Image, Purchase Decision

In this study, nano-ZrO 2, which was treated by silane couple agent, incorporated in phenyl silicone rubber at low concentration (≤3.0%) and cured by Room Temperature Vulcanized (RTV) method.The effects of different additive amount of nano-ZrO 2 on the mechanical properties, thermal conductivity and electrical conductivity of phenyl silicone rubber were investigated.The thermal conductivity, tensile strength and volume resistivity of nanocomposites increased firstly and then decreased.The dielectric constant of nanocomposites decreased firstly and then increased with the content of nanoparticles.We were interested to find that phenyl silicone rubber had a maximum thermal conductivity (0.399W/(m• K)), a maximum volume resistivity (1.08×10 12 Ω•cm)and a minimum dielectric constant (2.775), with a definite total mass fraction of the particle (0.06%).Compared with the thermal comductivity of pure silicone rubber (0.130W/(m• K)), it increased more than three times in the addition amount of 0.06wt%.Moreover, the silicone rubber keeps a high tensile strength.