Path Planning Using Optimal Path Search Algorithms and Smoothing for Polymer Soft Robots in a Static Environment

per ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-06111515articlePath Planning Using Optimal Path Search Algorithms and Smoothing for Polymer Soft Robots in a Static EnvironmentAli Esmaillialiesmailli@semnan.ac.ir1Mohammad Hossein Khalesimhkhalesi@semnan.ac.ir2Mohammadreza Doostmohammadian doost@semnan.ac.ir3Semnan UniversitySemnan UniversitySemnan UniversityPolymer soft robots with flexible bodies require smooth paths with continuous curvature for safe navigation. However, classical path planning algorithms such as Dijkstra and A* generate only the shortest path with sharp turns, which is incompatible with the kinematics of these robots. In this study, a path smoothing method is proposed by replacing right-angle corners with circular arcs of variable radius, and evaluated in grid environments with 250 to 1000 random obstacles. Sensitivity analysis shows that increasing obstacle density drastically raises the percentage of path length increase; for instance, in the 1000-obstacle scenario, the path length increases by up to 23% for a radius of 4 meters. The bending efficiency ratio decreases from 90% at a radius of 0.5 m to 20% at 4 m, while the efficiency ratio maintains double-digit values for radii smaller than one meter across all scenarios. Moreover, the average safe distance from obstacles remains around 17 meters in the worst case. Computationally, the A* algorithm performs significantly faster than Dijkstra. The findings provide a quantitative framework for selecting the bending radius according to the requirements of polymer soft robots. This approach can serve as a basis for real‑time path design for polymer soft robots in static, highly cluttered environments.http://irdpt.ir/Article/53574Polymer soft robot path planning algorithm path smoothing static environmentper ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-061111725articleAdvanced polymer nanocomposites for CO₂ absorption: from design to application in greenhouse gas reductionMohammad khalili mahanikhalilimahani80@gmail.com1The increasing concentration of carbon dioxide in the atmosphere, as the primary greenhouse gas, has necessitated the development of efficient and novel capture technologies. Traditional methods, such as liquid amine scrubbing, suffer from drawbacks including high energy consumption, equipment corrosion, and solvent degradation. In this context, solid adsorbents, particularly polymer nanocomposites, have gained significant importance due to their high specific surface area, functionalizability, and ease of regeneration. In this review article, the design principles, adsorption mechanisms (physical, chemical, and combined), types of polymer matrices (polyimide, polysulfone, polyethyleneimine), and effective nanofillers (metal-organic frameworks, graphene oxide, carbon nanotubes, porous nanosilica) are investigated. The results indicate that through amine functionalization, optimal selection of nanofillers, and the simultaneous combination of physical and chemical adsorption, a significant improvement in performance can be achieved. Fabrication methods include solution mixing, melt compounding, and in-situ polymerization. The main challenges include moisture stability, high cost of nanofillers, and process scalability. Key applications of this technology include CO₂ separation from power plant flue gas, natural gas sweetening, and direct air capture. With advances in green synthesis and the development of mixed matrix membranes, polymer nanocomposites offer a promising outlook for a low-carbon future. Simultaneous optimization of components and operating conditions will be key to achieving desirable industrial performance.http://irdpt.ir/Article/53505Polymer nanocomposite selective adsorption carbon dioxide greenhouse gases amine functionalityper ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-061112738articleThe most important rubber plants in the world and the rubber suitable species for Iranmehri nadiri nirimnadiriniri@yahoo.com1-The purpose of this research is to introduce the most important rubber plants in the world, whether trees, shrubs, bushes, or herbs. It also addresses the appropriate conditions for cultivation, keeping, and harvesting, as well as the suitable species for Iran. In this study, preliminary information on the most important plants containing rubber has been provided, and detailed information about the introduced plants has been avoided. It should be noted that in the present study, the name natural rubber does not refer only to rubber obtained from the sap of the Hevea tree, but rather natural rubber is used in its broadest meaning and occasionally refers to other types with different formulas and percentages of rubber content. Studies have shown that the production of some types of natural rubber in Iran is quite possible and that the production of this material in Iran is practical on an economic and commercial scale. It is obvious that with sufficient and methodical research, and the correct selection of the appropriate rubber plant for each region, and the elimination of their agrotechnical and agronomic problems, reaching the current import limits of natural rubber will not be far from being achieved. After the appropriate type of plant has been selected for the country, appropriate technology must be obtained or designed within the country to convert the leachate into solid rubber, so that various types of solid natural rubber can be produced on a mass scale.http://irdpt.ir/Article/53775Rubber plants Natural rubber Hevea tree Suitable species for Iran. per ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-061112951articleA Review on Emerging Granule-Based 3D Printing TechnologyAtefeh Nejadebrahimatefe.nejadebrahim@gmail.com1Zeinab Akbarianzeinabakbarian@mail.ir2Polymer Engineering Department, Qom University of Technology, P.O. Box: 1519-37195, Qom, IranFused granular fabrication, as an emerging extrusion-based additive manufacturing technology, has gained increasing attention as a promising alternative to conventional filament-based systems due to its direct utilization of polymer pellets as feedstock. Eliminating the intermediate filament production step not only reduces material and processing costs but also enhances flexibility in material selection and enables the development of diverse polymeric and composite formulations. These advantages position pellet-based printing as a suitable approach for manufacturing engineering components, biocompatible structures, and large-scale applications. The performance of pellet-fed systems is strongly influenced by the intrinsic properties of the feedstock and the processing parameters. In polymer composites, filler characteristics—including type, particle size, morphology, aspect ratio, and dispersion quality within the polymer matrix—play a critical role in determining melt rheological behavior, extrusion stability, interlayer adhesion, dimensional accuracy, and the final mechanical and functional properties of printed parts. Therefore, successful design of printable formulations requires a comprehensive understanding of the interactions among material structure, filler characteristics, and processing conditions. This review article discusses the fundamentals, advantages, challenges, and applications of granule-based 3D printing and provides a technical and economic comparison with filament-based additive manufacturing. Furthermore, the role of biocompatible polymers and composite systems, the influence of filler characteristics on printability and part performance, and the major challenges in advancing this technology are examined. Finally, future research directions aimed at improving print quality, developing advanced materials, and expanding industrial and biomedical applications are outlined.http://irdpt.ir/Article/536363D Printing Material Extrusion Printing Fused Granular Fabrication Biocompatible Polymersper ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-061115371article123Majid Mirzaeemjmirzaei@nri.ac.ir1Fire-retardant and fire-resistant coatings, as one of the most efficient and cost-effective passive protection strategies, play a key role in delaying ignition, reducing heat transfer, and limiting flame spread. This review article aims to systematize the existing knowledge in four main areas: first, the fundamentals and mechanisms of action, distinguishing between two categories of intumescent coatings (forming a swollen char layer with expansion capability of up to 100 times) and non-intumescent coatings (gas-phase mechanism or glassy layer formation). Second, formulation optimization based on industrial experimental evidence, demonstrating that the selection of an appropriate polymer binder, optimal ratio of main components, and nano-clay and reinforcing fiber additives have a direct impact on the thermal stability and integrity of the char layer. Third, emerging technologies such as nanocomposites and the sol-gel method, which, by creating transparent coatings while preserving the aesthetic appearance of the substrate, have significantly expanded the application range of these systems. In the final section, considering the challenges associated with the direct application of coatings onto sensitive substrates (chemical damage, reduced mechanical strength, and aesthetic alterations), the "indirect application" approach onto supporting materials is proposed as a low-impact strategy consistent with the principles of reversibility. Nevertheless, the lack of systematic studies in direct comparison of different formulations and evaluation of the long-term durability of these coatings remains a fundamental gap in current knowledge.http://irdpt.ir/Article/53753Intumescent coatings non-intumescent coatings nanocomposite sol-gel method passive fire protection formulation optimizationper ipstsپژوهش و توسعه فناوری پلیمر ایران 2538-3345 2588-39332026-061117382articleBiodegradable Smart Polymers Donya Namadi vosoughidonyavosough1384@gmail.com1Fatemeh Zeinoddinifatemehzeinoddini1232@gmail.com2Mehrnoush Mohammadimehrnoush_mohammadi@yahoo.com3Department of Chemical Engineering, South Tehran Campus(ST.C.), Islamic Azad University,Tehran, Iran.Department of Chemical Engineering, South Tehran Campus(ST.C.), Islamic Azad University,Tehran, Iran.Department of Chemical Engineering, South Tehran Campus(ST.C.), Islamic Azad University,Tehran, Iran.Biodegradable smart polymers, as a novel class of advanced materials, have garnered significant attention in recent research due to their unique combination of two key features: responsiveness to external stimuli and controlled biodegradability. These polymers react stimuli such as changes in temperature, pH, light and magnetic fields and have been developed in various types including shape-memory, self-healing, piezoelectric and chromogenic. The impressive advantages of these materials, including high biocompatibility, environmental safety and stability, along with the ability to precisely tune their degradation rate, make them suitable for a wide range of applications. Fields such as advanced drug delivery systems, tissue engineering, smart food packaging, biosensors, nanotechnology and smart agriculture are among the most important application areas for these polymers. Recent research focuses on emerging technologies like four-dimensional (4D) printing, the production of nature-inspired self-healing materials and advanced medical applications. However, the development and commercialization of these polymers face challenges such as high production costs and difficulties in precisely controlling the degradation rate. Activities have also been carried out in Iran to produce these materials, which require technological support, effective policymaking and targeted investment for advancement and expansion. These materials, with their vast potential, promise a bright future in various  industrieshttp://irdpt.ir/Article/53630Polymer Smart Biodegradable Natural polymers Synthetic polymers