Cold spray additive manufacturing (CSAM) is a cutting-edge high-speed additive manufacturing process enabling the production of high-strength components without relying on traditional high-temperature methods. Unlike other techniques, CSAM produces oxide-free deposits and preserves the feedstock’s original characteristics without adversely affecting the substrate. This makes it ideal for industries requiring materials that maintain structural integrity. This paper explores strategies for improving material quality, focusing on nozzle design, particle size distribution, and fine-tuning of process parameters such as gas pressure, temperature, and spray distance. These factors are key to achieving efficient deposition and optimal bonding, which enhance the mechanical properties of the final products. Challenges in CSAM, including porosity control and achieving uniform coating thickness, are discussed, with solutions offered through the advancements in machine learning (ML). ML algorithms analyze extensive data to predict optimal process parameters, allowing for more precise control, reduced trial-and-error, and improved material usage. Advances in material strength, such as enhanced tensile strength and corrosion resistance, are also highlighted, making CSAM applicable to sectors like aerospace, defense, and automotive. The ability to produce high-performance, durable components positions CSAM as a promising additive-manufacturing technology. By addressing these innovations, this study offers insights into optimizing CSAM processes, guiding future research and industrial applications toward more efficient and high-performing manufacturing systems.

The global demand for button mushrooms has surged in recent years, driven by their health benefits, creating a significant challenge for the mushroom industry in meeting this increasing demand. The increasing reliance on human labor, which is becoming unsustainable due to labor shortages and rising wage costs, highlights the urgent need for automated harvesting solutions. This review examines the integration of automated systems in button mushroom harvesting, delving into the key components such as robots, mechanisms, machine elements, programming, and algorithms. It offers a thorough analysis of the performance, design, operational mechanisms, and advantages and limitations of robotic systems, comparing the different methods employed in automated harvesting. This paper compares the performance of all the mushroom harvesters, including the commercially available ones with manual harvesting, and identifies their potential and limitations. The commercial harvesters are shown to pick 2000 mushrooms per hour on average, which is similar to how much a skilled worker picks at the same time. However, commercial automation harvesting has a relatively low success rate, high initial cost, high operating cost, and energy consumption, identifying areas for future research and challenges. This paper serves as a valuable resource for researchers and industry professionals striving to advance automated harvesting technology and improve its efficiency in meeting the rising demand for button mushrooms.

CSAM is a solid-state process for depositing metal or metal-based composite materials in which the fine particles of metal or composite material are accelerated to supersonic velocity, making successful bonding feasible due to the high-impact velocity and heavy plastic deformation, all without the melting of the feedstock material. This review examines the basic CSAM mechanism, including deposition dynamics, bonding mechanism, dynamic recrystallization, residual stress evolution, and post-spray heat treatments which affect microstructural and mechanical properties. Although controlled by a few key factors like particle velocity, strain rate, and temperature rise, the bonding efficiency itself refines the grains through dynamic recrystallization, hence improving coating strength and performance. The predominating compressive residual stresses that enhance fatigue resistance and mitigation strategies to improve coating durability by post-spray annealing and laser peening are discussed. This review, by providing an overview of material behavior, optimization techniques, and advanced modeling approaches, underlines the CSAM potential for high-performance applications in aerospace, biomedical industries, and machinery. It further underlines its importance for the advancement of manufacturing innovation and materials science.

Button mushrooms (Agaricus bisporus) grow in multilayered Dutch shelves with limited space between two shelves. As an alternative to conventional hand-picking, automated harvesting in recent times has gained widespread popularity. However, automated harvesting of mushrooms faces critical challenges in the form of growing environment, limited spaces, picking forces, and efficiency. End effectors for picking button mushrooms are an integral part of the automated harvesting process. The end effectors developed so far are oversized, bulky, and slow and thus are unsuitable for commercial mushroom harvesting applications. This paper introduces a novel three-finger hybrid gripper with rigid and soft parts, specifically designed for harvesting button mushrooms in automated systems even on narrow shelves. It discusses the design, fabrication, force analysis, and picking performance of the gripper in detail for both individual and clustered mushrooms. The results indicate that the gripping force depends on mushroom density and size. The inclusion of textured soft pads on gripper fingertips performs better compared with plain soft pads by reducing force by up to 20% and improving picking time. The gripper achieved a 100% picking success rate for single-grown mushrooms and 64% for clusters, with reduced picking times compared with existing end effectors. However, harvesting clustered mushrooms led to increased damage, suggesting the need for future improvements.

Floating treatment wetlands (FTWs) are engineered systems that utilize floating platforms planted with aquatic vegetation to treat polluted water such as stormwater, agricultural runoff, and wastewater. FTWs have emerged as promising and environmentally sustainable solutions for water purification. This review synthesizes the current knowledge on FTW design, plant selection, and performance evaluation. It highlights key factors influencing nutrient and heavy metal removal, including the hydraulic retention time, mat thickness, and types of plant species. Recent findings on the roles of root architecture, microbial interactions, and seasonal variability in treatment efficiency are also discussed. Additionally, the review explores advanced analytical methods for monitoring water quality and assessing plant growth and contaminant uptake. Case studies from both laboratory- and field-scale experiments illustrate how variation in FTW configurations impacts pollutant removal efficiency. The review concludes by identifying critical research gaps, including the need for standardized monitoring protocols, strategies to enhance long-term performance, and the integration of FTWs with complementary treatment technologies to improve effectiveness across diverse aquatic environments.

Floating treatment wetlands (FTWs) are engineered systems that use floating platforms planted with aquatic vegetation to treat polluted water such as stormwater, agricultural runoff and wastewater. FTWs have emerged as promising and environmentally sustainable solutions for water purification. This review synthesized current knowledge on FTWs design, plant selection, and performance evaluation. It highlights key factors influencing nutrient and heavy metal removal, including hydraulic retention time, mat thickness, and plant species. Recent findings on the roles of root architecture, microbial interactions, and seasonal variability in treatment efficiency are also discussed. Additionally, the review explores advanced analytical methods for monitoring water quality and assessing plant growth and contaminant uptake. Case studies from both laboratory and field-scale experiments illustrate how variation in FTW configurations impacts pollutant removal efficiency. The review concludes by identifying critical research gaps, including the need for standardized monitoring protocols, strategies to enhance long-term performance, and the integration of FTWs with complementary treatment technologies to improve effectiveness across diverse aquatic environments.