Manufacturing Challenges Research Articles

Future Prospects and Challenges in Additive Manufacturing for Complete Dentures: A Narrative Review

The utilization of computer-assisted design and computer-assisted manufacturing (CAD/CAM) techniques in the creation of complete dentures (CDs) has piqued the interest of many people. This article seeks to provide a comprehensive, critical, and objective analysis of the current knowledge of CDs and related technology. The aim of this study is to assess existing literature concerning 3D-printed complete dentures, covering aspects like innovative biomaterials, manufacturing methods and processes, workflow, and clinical effectiveness. The design of the current study included an initial review of 172 titles, an appraisal of abstracts, and finally a selection of articles for rigorous textual analysis. Inconsistencies discovered throughout the selection process were amicably resolved through discourse, culminating in the identification of 65 items. The publications retrieved from a thorough search of the PubMed, Scopus, and Embase databases spanned the years 1994 to 2023. Contemporary digital technology provides evident advantages, but its successful incorporation necessitates meticulous preparation. In the realm of dental healthcare, the digital workflow showcases versatility and a range of applications.

Inefficient transcription is a production bottleneck for artificial therapeutic BiTE® proteins

Antibodies are potent biopharmaceuticals used to treat severe diseases, including cancers. During the past decade, more complex modalities have been developed including bispecific T-cell engager (BiTE®) molecules, e.g. by Amgen. However, non-natural and complex molecule formats often prove to be difficult-to-express (DTE), which is the case for BiTE® molecules. Due to the growing importance of multispecific modalities such as half-life extended (HLE) BiTE® and HLE dual-targeting bispecific T-cell engager (dBiTE) molecules, this artificial class of therapeutic proteins was investigated for molecular bottlenecks in stable production cell lines, by analyzing all relevant steps of recombinant protein production. As a result, drastically reduced intracellular BiTE® molecule-encoding mRNA levels were identified as a potential production bottleneck. Using in vitro transcription (IVT), the transcription rate of the BiTE® molecule-encoding mRNA was identified as the root cause for reduced amounts of intracellular mRNA. In an attempt to improve the transcription rate of a BiTE® molecule, it could be demonstrated that the artificial and special structure of the BiTE® molecule was not the rate limiting step for reduced IVT rate. However, modulation of the primary DNA sequence led to significant improvement of IVT rate. The analyses presented provide insight into the HLE BiTE® / HLE d(BiTE®) class of DTE proteins and perhaps into other classes of DTE proteins, and therefore may lead to identification of further production bottlenecks and optimization strategies to overcome manufacturability challenges associated with various complex therapeutics.

The Importance and Challenges of Primary Chicken Embryo Liver Cells in Studies of Poultry Viral Diseases: A Review

Primary chicken embryo liver (CEL) cells are derived from the liver tissue of chicken embryonated eggs (CEE) using an aseptic isolation technique and growth under a controlled atmosphere in an artificial environment for cell attachment and proliferation. Although this primary cultured cell has been established for more than six decades, utilization of primary cells is still the preferable medium nowadays as the “gold standard” due to several advantages over other diagnostic techniques. Cells provide better adaptability of the viruses and easily mimic the natural host environment with high virus titration. The volume of virus suspension could be increased by applying an immortal chicken embryo liver-derived cell line. The current review aimed to highlight the importance and challenges of using primary chicken embryo liver cells in poultry virus studies. Primary CEL cells are widely used as an alternative host for diagnosis of infectious poultry viruses, cultivation and passaging of virus isolates, and vaccine production. Yet, there are some challenges and limitations in handling this primary cell, which requires appropriate facilities and environment to sustain the rapid growth of confluent monolayer cells, as highlighted in this paper. The availability of specific pathogen-free CEE is a major concern due to limited resources globally, thus creating a challenge for vaccine manufacturers to upscale the cultured cells. Future improvement of primary cell culture preparation necessitates new technology by applying cellular microcarrier in the bioreactor machine for efficient cell growth and subsequent routine virus cultivation. This study can help the researchers understand the advantages of primary CEL cells and their applications due to their significant impact on poultry viruses.

Leveraging the Snap Buckling of Bistable Magnetic Shells to Design a Refreshable Braille Dot

AbstractA design concept is proposed for the building block, a dot, of programmable braille readers utilizing bistable shell buckling, magnetic actuation, and pneumatic loading. The design process is guided by Finite Element simulations, which are initially validated through precision experiments conducted on a scaled‐up, single‐shell model system. Then, the simulations are leveraged to systematically explore the design space, adhering to the standardized geometric and physical specifications of braille systems. The findings demonstrate the feasibility of selecting design parameters that satisfy both geometric requirements and blocking forces under moderate magnetic fields, facilitated by pneumatic loading to switch between the two stable states. While the study is focused on experimentally validated numerical simulations, it is also identify several manufacturing challenges that need to be resolved for future physical implementations .

A Self-Healing System for Polydicyclopentadiene Thermosets.

Self-healing offers promise for addressing structural failures, increasing lifespan, and improving durability in polymeric materials. Implementing self-healing in thermoset polymers faces significant manufacturing challenges, especially due to the elevated temperature requirements of thermoset processing. To introduce self-healing into structural thermosets, the self-healing system must be thermally stable and compatible with the thermoset chemistry. This article demonstrates a self-healing microcapsule-based system stable to frontal polymerization (FP), a rapid and energy-efficient manufacturing process with a self-propagating exothermic reaction (≈200 °C). A thermally latent Grubbs-type complex bearing two N-heterocyclic carbene ligands addresses limitations in conventional G2-based self-healing approaches. Under FP's elevated temperatures, the catalyst remains dormant until activated by a Cu(I) co-reagent, ensuring efficient polymerization of the dicyclopentadiene (DCPD) upon damage to the polyDCPD matrix. The two-part microcapsule system consists of one capsule containing the thermally latent Grubbs-type catalyst dissolved in the solvent, and another capsule containing a Cu(I) coagent blended with liquid DCPD monomer. Using the same chemistry for both matrix fabrication and healing results in strong interfaces as demonstrated by lap-shear tests. In an optimized system, the self-healing system restores the mechanical properties of the tough polyDCPD thermoset. Self-healing efficiencies greater than 90% via tapered double cantilever beam tests are observed.

Rheology in Product Development: An Insight into 3D Printing of Hydrogels and Aerogels.

Rheological characterisation plays a crucial role in developing and optimising advanced materials in the form of hydrogels and aerogels, especially if 3D printing technologies are involved. Applications ranging from tissue engineering to environmental remediation require the fine-tuning of such properties. Nonetheless, their complex rheological behaviour presents unique challenges in additive manufacturing. This review outlines the vital rheological parameters that influence the printability of hydrogel and aerogel inks, emphasising the importance of viscosity, yield stress, and viscoelasticity. Furthermore, the article discusses the latest developments in rheological modifiers and printing techniques that enable precise control over material deposition and resolution in 3D printing. By understanding and manipulating the rheological properties of these materials, researchers can explore new possibilities for applications such as biomedicine or nanotechnology. An optimal 3D printing ink requires strong shear-thinning behaviour for smooth extrusion, forming continuous filaments. Favourable thixotropic properties aid viscosity recovery post-printing, and adequate yield stress and G' are crucial for structural integrity, preventing deformation or collapse in printed objects, and ensuring high-fidelity preservation of shapes. This insight into rheology provides tools for the future of material design and manufacturing in the rapidly evolving field of 3D printing of hydrogels and aerogels.

Investigation of surface imperfection in freeform optics with high-order XY polynomial design

Freeform surfaces find potential applications in optics but pose new challenges for manufacturing and functional testing. A basic description of such surfaces is observed in terms of surface spatial frequencies which have been altered as a result of evolution in the fabrication of optics. While mid-spatial-frequency (MSF) errors arising from manufacturing and metrology processes are well documented, our investigation reveals that such errors originate not only during these stages but also during the surface construction at the design phase, particularly for high-order XY polynomial optical surfaces. The presence of MSF errors can significantly affect the performance of high-performance optical systems across various applications. The study discussed in this paper focuses on the relationship between the resolution of the design dataset of freeform surfaces with high-order polynomials and the subsequent surface imperfections in the production of precision optics. The main contributions of this investigation are the identification of MSF errors at surface construction of the design phase and the control over the MSF errors in design dataset using the 2nd-order Gaussian filtration which will bridge the gap between freeform optics design and ultra-precision manufacturing.

Water vapour resistance modelling of basic weaving structure

Water vapour diffusion through textile fabrics plays a crucial role in maintaining body comfort. Developing and producing comfortable textiles is a major challenge for manufacturers of fibres, yarns and fabrics. This study aims to develop a simple model to predict the water vapour permeability of textile fabrics as a function of their structural parameters to assist manufacturers in developing comfortable fabrics. To achieve this goal, geometric modeling of the woven structure was proposed to calculate porosity at the micro-and macro-pores level. Two mathematical models were introduced based on the principle of diffusion of water vapour through a textile fabric. To validate the two models, a series of 18 samples was prepared with three basic fabric structures: Plain, Twill and Turc Sateen. To vary the compactness of the structures, three weft densities were chosen: 18, 21 and 24 picks/cm. In addition, since the material influences water vapour diffusion, two types of weft yarns were inserted: 50% CO/50% PET and 100% PET. The results show that the two models are reliable for predicting water vapour resistance (Ret) depending on the structural parameters of the textile fabric.

Систематический обзор технологий производства металлической пены

Introduction. The paper presents a comprehensive overview of the manufacturing methods, materials, properties, and challenges associated with cellular metallic foams, primarily focusing on aluminum and titanium-based foams. Cellular metallic foams are gaining interest due to its unique combination of low density, high stiffness, and enhanced energy absorption capabilities. Cellular metallic foam is renowned for its special combinations of physical and mechanical characteristics, containing their increased stiffness, specific strength at high temperatures, light weight, and good energy absorption at relatively low plateau stress. It has extensive uses in the automotive, shipbuilding and space industries. It has high porosity, low relative density and high strength, which increases performance of the product. The aerospace and automotive industries require a material with a high strength-to-weight ratio. Methods. To meet this need, many metal foam production methods have been developed, such as melt route method, deposition method and powder metallurgy method. Melt route method is widely used to manufacture metallic foam as compared to other methods. Results and Discussion. In the production of aluminum foams, the melt route method is usually used. Titanium hydride (TiH2) has been a popular foaming agent, but its high decomposition rate and cost limitations have led to the development of alternative foaming agents, such as CaCO3 (calcium carbonate). Titanium foam is often manufactured using the space holder method. This method involves mixing titanium powder with a space holder material, forming a preform, and then sintering to remove the space holder and produce a porous structure as the space holder method allows for precise control over the properties of the foam, including pore size, porosity, and relative density. Results also indicate that porosity in cellular metallic foams can range from 50 % to 95 %, as reported in various journals. Pore structures can include mixed types, open cells, and closed cells, each offering different mechanical and thermal properties. It is also observed from various literature sources that relative density, which is the ratio of the foam's density to the bulk material's density, varies from 0.02 to 0.44 based on the production method used.

Progress and Remaining Challenges for MicroLED Volume Manufacturing.

Progress and Remaining Challenges for MicroLED Volume Manufacturing.

The comparability tales: A phase-appropriate roadmap for CGT drug product development

Cell and gene therapies (CGTs) have revolutionized patient outcomes and provided careoptions for previously untreatable conditions. The clinical and commercial progress of CGT therapies is hindered bychemistry, manufacturing, and control (CMC) challenges. This article summarizes recommendations from the 2023 Annual Meeting CMC sessions wherein speakers advocated for science-driven comparability strategies, proactive risk assessments, clearer regulatory guidance, and a shift from retrospective to prospective studies. Planning formanufacturing changes, statistical approaches, and consideration of multiple product versions also emerged as crucial elements to help sponsors navigate CMC hurdles for successful CGT clinical and commercial development.

A thermo-mechanical model for hot cracking susceptibility in electron beam powder bed fusion of Ni-base superalloys

Hot cracking is a major challenge in the additive manufacturing of Ni-base superalloys. Most cracking indicators only consider the alloy composition and its effects on solidification behavior, strength, and ductility. We propose a new model that extends these classical cracking indicators by additionally incorporating the transient thermo-mechanical state during melting and solidification. The model is derived from insights into the cracking of thin layers and is mainly based on the elastic strain energy available to drive crack opening in a critical temperature interval. The underlying thermo-mechanical process simulations are implemented in a custom computational framework designed to efficiently model powder bed fusion. The model predictions are validated against experimentally measured crack densities in CMSX-4 processed by electron beam powder bed fusion. The proposed model allows for rationalizing the dependence of cracking susceptibility on the thermal history, which is controlled by scan speed and beam power. Finally, the model is applied to develop a crack mitigation strategy by reducing the built-up strain energy density. This is achieved by heating the melting area to a high temperature before melting, thereby reducing the temperature gradient.

Design and kinematic modeling of a mobile manipulator with hybrid locomotion for agricultural applications

In agriculture, one of the future solutions to eliminate the negative effect on the environment of the classical machineries is to use mobile robots. Small groups of mobile robots will interact with each other in order to inspect, to process or to harvest crops. These robots will have to work in a changing environment, in terms of terrain or road surfaces, the light of the ambient, animals, etc., aspects that will pose challenges for mobile robots. To facilitate the use of robots in agriculture, they must have a simple construction, be extremely reliable, flexible and, last but not least, cheap. These aspects have as effect new challenges for robot manufacturers to find technical solutions to meet the mentioned requirements. In this paper, a conceptual design and modeling of a mobile manipulator with hybrid locomotion, which may be used in agriculture for applications, such as tilling, seeding, weeding, etc, will be discussed.

Morphing concepts in the field of rotorcraft

Drawing inspiration from avian creatures, aeronautical engineers strive to create an ideal wing design that can seamlessly perform in various flight conditions. Avian creatures, as well as bats and other flying organisms, exhibit a striking aptitude to adjust the lift produced by their wings, displaying the capacity to repeatedly tailor their wing configurations to match specific environmental conditions. An example of this is when their wings are tightly tucked during dives for hunting, or fully extended during gliding to conserve energy. Moreover, these organisms can manipulate the curvature and twist of their wings to maintain precise control over their aerial maneuvers. In contrast, engineers in the aircraft industry continue to rely on the standard, robust and structured “one-point design” approach, which remains the most practical and feasible method to apply. Nonetheless, advancements in technology have emerged to address long-standing challenges in wing manufacturing that were previously deemed insurmountable. This convergence of different technologies has given significant momentum and recognition to the field of “morphing discipline”. When considering an aircraft, shape changes primarily relate to the wing of a fixed-wing aircraft or the blade of a rotorcraft. The concept of achieving a "smooth" shape change stems from the crucial need for drag reduction and improved flow quality, resulting in improved overall performance. The state-of-the-art morphing concepts applied to rotorcrafts comprise a wide range of investigations aimed at improving performance. Looking ahead, the primary challenge for morphing technology will be to persuade the industry of its tangible benefits. This encompasses enhanced aerodynamic efficiency, minimized installation footprint when contrasted with conventional control surface mechanisms, reduced overall weight, and an equivalent standard of safety. This research provides an overview of the current development of different control devices and explores the impact of previous and continuous research endeavors in this field. Numerous ideas for managing airflow have been explored with the aim of enhancing the performance abilities of rotary-wing aircraft. These include active morphing in rotorcraft such as leading edge slats, trailing edge flaps, and passive morphing in rotorcraft such as variable rpm rotorcraft. The aim of these blade modifications is to achieve various desired effects such as increasing the maximum lift coefficient, reducing drag, and minimizing vibratory loads. Convincing the industry of these advantages will play a crucial role in shaping the future of morphing technology.

Navigating the Potential Applications and Challenges of Intelligent and Sustainable Manufacturing for a Greener Future

Navigating the Potential Applications and Challenges of Intelligent and Sustainable Manufacturing for a Greener Future

Partial sound source estimation with Helmholtz inverse beamforming as a part of pass-by noise virtualization

Noise has an impact on human health. Therefore, pass-by noise of motor vehicles is legally regulated. The latest norm of the Economic Commission for Europe is ECE R51.03. According to this norm, pass-by noise of motor vehicles must be reduced to a sound pressure level of less or equal 68 dB(A). This poses a challenge for original equipment manufacturers. Firstly, they need a detailed analysis on the influence of contributing vehicle components such as engine, exhaust system and tires to the over-all pass-by noise. Secondly, original equipment manufacturers strive to shorten development cycles and lower production costs. Therefore, predictions of the expected physical behaviour of future cars have gained increasing importance. This leads to the emergence of new technological concepts like digital twins. This paper presents an extension of our latest approach to partial sound source analysis of simulated pass-by noise, i.e. Helmholtz Inverse Beamforming. Moreover, we present the embedding of the results of Helmholtz Inverse Beamforming in a comprehensive virtualization concept of pass-by noise engineering. By combining Helmholtz Inverse Beamforming with machine learning predictions of future cars, this concept enables us to derive target values of acoustic components regarding their pass-by noise.

Delivery of Obecabtagene Autoleucel (obe-cel, AUTO1) for the FELIX Pivotal Study Demonstrating Robust Cell Processing, Robust Release Testing, and Reliable Logistics, Together with Readiness for Sustainable Patient (pt) Care

Background: Obe-cel is an autologous chimeric antigen receptor (CAR) T cell product whose CD19 binding domain has a unique fast off-rate and was designed for improved safety and persistence over existing CD19 CAR T therapies. Successful CAR T therapy relies on a rapid and effective end-to-end process. The challenge for product manufacturing is twofold: first, pts with high tumor burden can have T cells that are highly differentiated and exhausted; second, pts with leukemic cells in circulation have apheresis containing a substantial proportion of leukemic cells that require removal before manufacture can start. Having robust, reliable manufacturing, testing, logistics processes, and teams that are able to provide a consistent CAR T product is key to achieving timely vein-to-certification/vein-to-delivery (V2C/V2D) targets. This abstract reports on the manufacturing, quality control (QC) and logistics processes set up for the FELIX study, and the impact of on-study optimization for scale up of production. Methods: The FELIX clinical study design required manufacturing, testing and logistics processes that could support a global, multicenter study with a target infusion of ~90 pts. The key elements were: 1) manufacturing and testing location: obe-cel was manufactured in Stevenage, UK, chosen because of proximity to a major international airport (London Heathrow) that provides logistics access to Europe and the US, and the ability to leverage existing knowledge and talent; 2) manufacturing process: manufacturing was carried out 7 days/week, was highly automated with mainly closed-system processing, using a Miltenyi Biotec Prodigy ® (https://www.miltenyibiotec.com), 3) analytical procedures: QC procedures, including measuring biological activity and sterility testing, were carried out in-house to reduce turnaround time (TAT); 4) logistics: TAT was minimized and reliability improved by establishing primary and secondary routes plus turnkey contingency plans with courier and charter flight options 5) targets: V2C (time from leukapheresis to quality release) and V2D (time from leukapheresis to delivery of product to the hospital) of ~23 and ~25 days, respectively, for the FELIX study. Results: Between Jul 2021 and Dec 2022 (FELIX Phase II Cohort A), the 32 clinical sites for FELIX in the US, UK and Spain were all supplied obe-cel from the UK. Median V2C and V2D times were 21 and 24 days, respectively. Despite the median leukemic B-cell content in apheresis being 21% (range 0-97%) and the median CD3+ T cell content being 13% (range 1-91%), 96% of manufactured obe-cel batches reached their target dose of 410 x 10 6 CAR T cells. From apheresis to product the median (range) percentage of naïve T cells increased from 20% (1-73%) to 31% (2-74%) while the medians for T CM and T EM remained unchanged at 13% to 13% and 19% to 17%, respectively, and the median TEMRA content decreased from 37% (range 4-93%) to 31% (range 5-90%), indicating that the manufacturing process managed to drive towards a less differentiated T cell phenotype in the final drug product. Transduction rates were consistently high with a median of 70% (range 14-87%). In the morphological Phase II Cohort A of the FELIX study, 112 pts were leukapheresed and 94 (84%) were dosed. All leukapheresis collections and cell product deliveries were executed successfully and with the expected quality, despite the challenges posed by the COVID-19 pandemic. In addition, US international airline flights decreased by 43 % (US Dept of Transportation, Bureau of Transportation Statistics; July 2023) compared with pre COVID-19 pandemic, but sample collection and product delivery were successfully maintained, with no batches impacted. Maintaining consistently short QC and release times were driven by streamlined analytical strategy and batch records. Conclusions: The FELIX study successfully demonstrated the robust operability of obe-cel manufacturing, QC and logistics processes, meeting target V2C and V2D. All apheresis starting material successfully processed despite the multitude of constraints posed by the COVID-19 pandemic. Further optimization and improvements made during the study increased reliability, consistency and precision of the manufacturing process, and supported the development of a new obe-cel manufacturing facility with greater production capacity that aims to achieve a ≥95% manufacturing success rate with ≤15-day V2C times.

API-192, an Allogeneic CD19/20 CAR-NKT Cell Product Derived from Cord Blood CD34+ HSPCs for the Treatment of B-Cell Malignancies

Autologous chimeric antigen receptor (CAR)-T cell therapies induce durable remissions and improve survival in patients with advanced B cell malignancies. However, challenges such as manufacturing variability, cost, and time to treatment highlight the need for an allogeneic, off-the-shelf approach that preserves the efficacy of autologous CAR-T. Additionally, antigen escape is one of the established mechanisms of resistance to current CAR-T therapies which target a single antigen. Classical natural killer T (NKT) cells express an invariant T cell receptor (iTCR) that is restricted to the conserved CD1d protein, making it a promising cell type for allogeneic therapies as they do not require TCR gene editing to avoid graft-vs-host (GvH) disease. Furthermore, NKT cells mediate dendritic cell cross-priming, target immunosuppressive myeloid cells/macrophages in the tumor microenvironment, and directly kill CD1d + tumor cells through the iTCR. Endogenous NKT cells are an extremely rare population in the blood (<1% of lymphocytes), posing manufacturing challenges. API-192 is a human cord blood CD34 + hematopoietic stem and progenitor cell-derived NKT cell product engineered to express dual CARs targeting CD19 and CD20 and armored with soluble IL-15 for improved expansion and persistence. The Appia Cells Utilized for Allogeneic (ACUA) platform enables the production of large numbers of product NKT cells co-expressing multiple transgenes at high purity (>90% iTCR + 19CAR + 20CAR +) with no purification step or gene editing. Phenotypically, API-192 cells are predominantly CD4 -CD8 - or CD4 -CD8 +, express major activating NK receptors, and harbor intracellular stores of cytotoxic molecules, resembling endogenous NKT cells. API-192 kills Raji and Nalm6 tumor cells in a CAR-specific and dose-dependent manner and can control multiple rounds of tumor challenge in vitro. API-192 secretes pro-inflammatory cytokines and proliferates in response to tumor antigen . In human tumor xenograft models in immunocompromised mice, API-192 robustly expands, suppresses tumor growth, and exhibits prolonged persistence, enabling control of a tumor rechallenge 70 days after initial dosing. API-192 expresses lower levels of MHC I and MHC II molecules relative to conventional CAR-T cells and elicits less IFN-γ release by NK and T cells in mixed lymphocyte reaction (MLR) assays, indicative of a more favorable immunogenic profile. Compared to conventional CAR-T cells, API-192 also secretes minimal levels of IFN-γ in response to co-culture with healthy donor peripheral blood mononuclear cells, consistent with the expression of a non-HLA restricted TCR and low GvH risk. These results demonstrate the feasibility, potency, and potential safety of API-192, warranting further development as a novel allogeneic therapy.

Potensi Penggunaan Selulosa Kelapa Sawit Sebagai Bahan Sneakers

The solution to the problem of environmental sustainability is increasingly urgent due to the growing number of consumers which is exacerbated by the use of raw materials for the manufacture of products that are not environmentally friendly. Therefore, the demand for environmentally friendly products or bioproducts has recently become increasingly popular and has become a challenge for manufacturers to increase production and innovation, especially in the footwear sector. One of the innovations that can be used to support the bioproduct mission is the use of material fiber derived from plant waste in the form of cellulose from empty palm oil bunches which has characteristics resembling synthetic leather. The research is supported by the results of a literature study that has been carried out as well as observations in the form of experiments testing several upper materials for resistance and moisture to testing cellulose materials in the sneaker product section. The experimental results show that cellulose materials can support the application of several anatomical parts of upper sneakers with supports in the form of a combination of materials such as cowhide, synthetic materials and corduroy fabrics as supports for cellulose materials. The results of the research are expected to raise awareness among users about the use of sustainable and recyclable materials that can be applied to fashion styles that can compete with non-bioproducts.

Underwater wet laser welding of duplex stainless steel under various water depths

Reports on experiments of underwater wet laser welding (UWLW) are scarce because of the poor forming quality of weldments. To address the key manufacturing challenges such as failure of welding with water depth exceeding 7 mm and the generation of pores and cracks which caused by the rapid water cooling, a specific self-designed flux assisted welding at different water depths (0–30 m) was innovatively proposed in this study. The microstructure, phase distribution, and properties of underwater wet laser welded duplex stainless steel joints were examined. The welding process successfully produced joints free from pores or cracks, even when performed within a 15 m water depth. In conjunction with thermodynamic calculation, the evolution process of welds and the effect of nickel from the flux on phases structure were analyzed. As the water depth increases and the welding speed decreases, the number of pores inside welds increase significantly, and no cracks are found. The penetration of all welds made in deep water is obviously smaller than that of shallow water and increased heat input does not seem to contribute to the increase of weld penetration. With the increase of water depth, a large amount of coarsened austenite consisted of columnar grains and cellular grains appear in weld zone. Texture and dislocation of the weld made in shallow water were investigated. Many dislocations including edge dislocations and dislocation entanglements arranged in austenite phase, while seldom dislocations appear in ferrite phase.