Promising Role of Polylactic Acid as an Ingenious Biomaterial in Scaffolds, Drug Delivery, Tissue Engineering, and Medical Implants: Research Developments, and Prospective Applications

In the present scenario, the research is now being focused on the naturally occurring polymers that can gradually replace the existing synthetic polymers for the development of bio composites having applications in medical surgeries and human implants. With promising mechanical properties and bio compatibility with human tissues, poly lactic acid (PLA) is now being viewed as a future bio material. In order to examine the applicability of PLA in human implants, the current article sheds light on the synthesis of PLA and its various copolymers used to alter its physical and mechanical properties. In the latter half, various processes used for the fabrication of biomaterials are discussed in detail. Finally, biomaterials that are currently in use in the field of biomedical (Scaffolding, drug delivery, tissue engineering, medical implants, derma, cosmetics, medical surgeries, and human implants) are represented with respective advantages in the sphere of biomaterials

Natural Fibers and Biopolymers Characterization: A Future Potential Composite Material

Now days, green composite materials are now gaining popularity for the various industrial applications. It is a combination of naturally occurring reinforcement like jute, sisal, flax, hemp, and kenaf; and matrix materials like biopolymers or bio resins which have been derived from starch, and vegetable oils. It is becoming more desirable due to its properties like biodegradability, renewability and environment friendly. The present paper presents the various natural fibers and their combinations with biopolymers. The paper also reflects the key issue related to hydrophilic nature of natural fibers and their remedies for a good fiber and bio polymer adhesion. Furthermore the strategy used and major attributes of the green composite are also discussed

Optimization on tribological properties of natural fiber reinforced brake friction composite materials: Effect of objective and subjective weighting methods

This research aims to study the effect of objective and subjective weighting methods in multi-attribute decision-making (MADM) and then develop a systematic framework for selecting the best natural fiber-reinforced friction composite for automobile braking applications. Therefore, sixteen friction composites with varying weight amounts (5, 10, 15, and 20 wt%) of pineapple, ramie, hemp, and banana fibers were fabricated and evaluated for tribological properties. The experimental results, such as friction coefficient, fade-recovery performance, friction fluctuations, wear, friction stability, and variability aspects, were discussed and considered performance attributes for selecting optimal composition. The results indicated that the incorporation of varying amounts of natural fibers has different effects on the tribological properties, making it challenging to prioritize the performance of the composites to choose the best from the set of composite alternatives. Therefore, EDAS (evaluation based on the distance from the average solution) MADM approach has been applied to pick the best alternative from sixteen natural fiber-based brake friction composites. As an input to EDAS, different types of objective and subjective weighting methods were used to identify the importance of each attribute. These methods include the CRITIC (criteria importance through inter-criteria correlation), entropy, BWM (best-worst method), and AHP (analytic hierarchy process). The results show that the composite alternative with 5 wt% ramie fiber exhibits the optimal tribological properties. The sensitivity analysis and validation reveal the robustness of the results, demonstrating that the same alternative dominates in diverse MADM and weighting conditions

A review on active techniques in microchannel heat sink for miniaturization problem in electronic industry

With continuous miniaturization of modern electronic components, the need of better cooling devices also keeps on increasing. The improper thermal management of these devices not only hampers the efficiency but can also cause permanent damage. Among various techniques, microchannel heat sink has shown most favourable performance. To further enhance the performance, two techniques i.e., active and passive are used. In passive technique, no external power source is required like heat sink design alteration and working fluid modification. External power source is necessary for heat transfer augmentation in the microchannel heat sink when using the active approach. Due to compact size of microchannel, active techniques are not used more often. However, the present work highlights the different active technique used in microchannel i.e., Electrostatic forces, flow pulsation, magnetic field, acoustic effects, and vibration active techniques. Above mentioned techniques have been analysed in detail

Waste marble dust-filled sustainable polymer composite selection using a multi-criteria decision-making technique

This research works with the optimal design of marble dust-filled polymer composites using a multi-criteria decision-making (MCDM) technique. Polylactic acid (PLA) and recycled polyethylene terephthalate (rPET)-based composites containing 0, 5, 10, and 20 wt% of marble dust were developed and evaluated for various physicomechanical and wear properties. The results showed that the incorporation of marble dust improved the modulus and hardness of both PLA and rPET. Moreover, a marginal improvement in flexural strength was noted while the tensile and impact strength of the matrices were deteriorating due to marble dust addition. The outcomes of wear analysis demonstrated an improvement in wear resistance up until 10 wt% filler reinforcement, after which the incidence of dust particles peeling off from the matrix was observed, thereby reducing its efficiency. The best tensile modulus of 3.23 GPa, flexural modulus of 4.39 GPa, and hardness of 83.95 Shore D were obtained for 20 wt% marble dust-filled PLA composites. The lowest density of 1.24 g/cc and the highest tensile strength of 57.94 MPa were recorded for neat PLA, while the highest impact strength of 30.94 kJ/m2 was recorded for neat rPET. The lowest wear of 0.01 g was obtained for the rPET containing 5 wt% marble dust content. The experimental results revealed that for the examined criteria, the order of composite preference is not the same. Therefore, the optimal composite was identified by adopting a preference selection index-based MCDM technique. The findings demonstrated that the 10 wt% marble dust-filled PLA composite appears to be the best solution with favorable physical, mechanical, and wear properties

Thermal and Sliding Wear Properties of Wood Waste-Filled Poly(Lactic Acid) Biocomposites

In our study, the effects of wood waste content (0, 2.5, 5, 7.5, and 10 wt.%) on thermal and dry sliding wear properties of poly(lactic acid) (PLA) biocomposites were investigated. The wear of developed composites was examined under dry contact conditions at different operating parameters, such as sliding velocity (1 m/s, 2 m/s, and 3 m/s) and normal load (10 N, 20 N, and 30 N) at a fixed sliding distance of 2000 m. Thermogravimetric analysis demonstrated that the inclusion of wood waste decreased the thermal stability of PLA biocomposites. The experimental results indicate that wear of biocomposites increased with a rise in load and sliding velocity. There was a 26–38% reduction in wear compared with pure PLA when 2.5 wt.% wood waste was added to composites. The Taguchi method with L25 orthogonal array was used to analyze the sliding wear behavior of the developed biocomposites. The results indicate that the wood waste content with 46.82% contribution emerged as the most crucial parameter affecting the wear of PLA biocomposites. The worn surfaces of the biocomposites were examined by scanning electron microscopy to study possible wear mechanisms and correlate them with the obtained wear results

Mechanical properties of fibre/filler based polylactic Acid (PLA) composites: a brief review

Being a biodegradable polymer, poly(lactic acid) (PLA) based composites receive greater preference over nonbiodegradable plastics. Poly(lactic acid) has to find its place in various applications such as polymer composites, agriculture, biomedical, etc. Polymer composites based on PLA possess comparable mechanical strength, endurance, flexibility and endures future opportunities. Several combinations of natural fibers and filler-based PLA composites have been fabricated and investigated for physical and mechanical changes. Moreover, several biopolymers and compatibilizers are added to PLA to provide rigidity. The paper presents a tabulated review of the various natural fiber/filter-based PLA composites and the preparation and outcomes. In addition, enhancement made by the reinforcement of nano filler in the PLA are also discussed in brief. The significance of PLA in the biomedical application has been discussed in brief. The paper also shed lights in the social and economic aspects of PLA

Optimal Design of Wood/Rice Husk-waste-Filled PLA Biocomposites Using Integrated CRITIC–MABAC-Based Decision-Making Algorithm

Based on the criteria importance through inter-criteria correlation (CRITIC) and the multi-attributive border approximation area comparison (MABAC), a decision-making algorithm was developed to select the optimal biocomposite material according to several conflicting attributes. Poly(lactic acid) (PLA)-based binary biocomposites containing wood waste and ternary biocomposites containing wood waste/rice husk with an overall additive content of 0, 2.5, 5, 7.5 and 10 wt.% were manufactured and evaluated for physicomechanical and wear properties. For the algorithm, the following performance attributes were considered through testing: the evaluated physical (density, water absorption), mechanical (tensile, flexural, compressive and impact) and sliding wear properties. The water absorption and strength properties were found to be the highest for unfilled PLA, while modulus performance remained the highest for 10 wt.% rice husk/wood-waste-added PLA biocomposites. The density of PLA biocomposites increased as rice husk increased, while it decreased as wood waste increased. The lowest and highest density values were recorded for 10 wt.% wood waste and rice husk/wood-waste-containing PLA biocomposites, respectively. The lowest wear was exhibited by the 5 wt.% rice husk/wood-waste-loaded PLA biocomposite. The experimental results were composition dependent and devoid of any discernible trend. Consequently, prioritizing the performance of PLA biocomposites to choose the best one among a collection of alternatives became challenging. Therefore, a decision-making algorithm, called CRITIC–MABAC, was used to select the optimal composition. The importance of attributes was determined by assigning weight using the CRITIC method, while the MABAC method was employed to assess the complete ranking of the biocomposites. The results achieved from the hybrid CRITIC–MABAC approach demonstrated that the 7.5 wt.% wood-waste-added PLA biocomposite exhibited the optimal physicomechanical and wear properties

Thermo-hydraulic investigation of open micro prism pin fin heat sink having varying prism sides

The current trend of miniaturization in many electronic devices, like computer processors, high-speed servers, MEMS devices, etc., has shown augmented performance. Still, thermal management is a significant concern for them. The present work performed a numerical analysis on the microchannel heat sink's open micro prism pin fin configuration (MCHS). The influence of prism pin fin sides (3 to 9) has been studied for copper substrate and working fluid water (single phase fluid flow). Finite volume-based commercial code has been opted to perform the numerical simulations. The present configurations simulated different Reynolds numbers (50–300) under the heat flux of 500 kW/m2. Observation revealed that the four-side arrangements have the best performance due to prominent secondary flow leading to efficient fluid mixing, whereas three-side configurations have the worst performance. Further, an increase in pin fin sides from 5 to 9 has almost negligible variation in thermal and hydraulic characteristics because of similar fluid flow characteristics. The four-side micro prism pin fin configuration has been further analysed by varying the prism radius from 0.175 mm to 0.325 mm. It was observed that a prism radius between 0.250 mm and 0.275 mm led to optimum overall performance due to more stable secondary fluid flow