Fabrication Challenges Research Articles

Demonstration of a High‐Performance 3 dB Power Splitter in Silicon Nitride Loaded Lithium Niobate on Insulator

AbstractLithium niobate on insulator (LNOI) has emerged as a promising platform for photonic integrated circuits (PICs) due to the excellent electro‐optic (EO) properties of lithium niobate (LN). However, such a platform still lacks many critical passive components with superior performance for constructing PICs. The 3 dB power splitters are one of the important passive components in PICs for separating and combining optical energy to construct the other crucial photonic devices such as Mach–Zehnder modulators, optical switches, and optical phased arrays, et al. In this contribution, an ultra‐broadband and compact 3 dB power splitter is proposed and demonstrated using a tapered subwavelength grating (SWG)‐assisted Y‐branch on a silicon nitride (Si3N4) loaded LNOI platform. The SWG is used to alleviate fabrication challenges and reduce radiation loss while increasing the evanescent coupling. The simulation result shows an excellent operation bandwidth of 800 nm (from 1.2 to 2.0 µm) at the insertion loss (IL) of 0.12 dB. The proposed device with a compact footprint (9.6 × 3 µm2) is finally fabricated on a Si3N4 loaded LNOI platform, and the experimental result shows the IL of <0.2 dB in the wavelength ranges from 1.5 to 1.6 µm, which makes it suitable for broadband PICs required for future communication systems.

A Review of Electrode Manufacturing Methods for Electrical Discharge Machining: Current Status and Future Perspectives for Surface Alloying

In electrical discharge machining (EDM), the tool electrode is one of the substantial components of the system, and it ensures the success or failure of the EDM process. The electrode’s role is to conduct electrical charges and erode the workpiece to the desired shape. Different electrode materials have different impacts on machining. Certain electrode materials remove metal quickly but wear out rapidly, while others degrade slowly but the material removal is too slow. The choice of the electrode has an influence on both the mechanical properties, such as metal removal rate (MRR), wear rate, surface finish, surface modification and machinability, and the electrical properties, such as sparking initiation, time lag, gap contamination and process stability. There are factors to consider when fabricating an electrode, which include the type of workpiece materials, the metallurgical alloying of the materials, the choice of fabrication techniques, the intended use of the electrode, and material cost. Considerable challenges in EDM electrode fabrication have been reported, which include excessive tool wear for green compact electrodes, high toughness for sintered electrodes, and poor rigidity for additively manufactured electrodes. To address these issues, researchers have explored different manufacturing methods, such as casting, conventional machining, electrodeposition, powder metallurgy and additive manufacturing. In this paper, the various techniques attempted and adopted in EDM electrode manufacturing are analyzed and discussed. This paper also sought to give insight into EDM, its various forms, the dielectric fluid’s properties, EDM electrode’s size and shape, the effects of the electrode on the EDM process, material removal, electrode wear, present technologies for electrode fabrication, and the limitations of these technologies. Finally, directions for future research are highlighted.

Nonvolatile tuning of Bragg structures using transparent phase-change materials

Bragg gratings offer high-performance filtering and routing of light on-chip through a periodic modulation of a waveguide’s effective refractive index. Here, we model and experimentally demonstrate the use of Sb2Se3, a nonvolatile and transparent phase-change material, to tune the resonance conditions in two devices which leverage periodic Bragg gratings—a stopband filter and Fabry-Perot cavity. Through simulations, we show that similar refractive indices between silicon and amorphous Sb2Se3 can be used to induce broadband transparency, while the crystalline state can enhance the index contrast in these Bragg devices. Our experimental results show the promise and limitations of this design approach and highlight specific fabrication challenges which need to be addressed in future implementations.

O-Band Grating Couplers Using Silicon Nitride Structures

To test silicon photonics component performances, a silicon (Si) grating coupler (GC) is used to couple the light from a single-mode fiber (SMF) into the chip. However, silicon nitride (Si3N4) waveguides have recently become more popular for realizing photonic integrated circuits (PICs), which may be attributable to their exceptional characteristics, such as minimal absorption and low back reflection (BR) in the O-band spectrum. Thus, to test the photonic chip, a waveguide converter from Si3N4 to Si needs to be added to the photonic circuit, which can lead to more power losses and BR. To avoid this conversion, we propose in this manuscript a configuration of a GC based on Si3N4 structures, which can be employed to minimize the footprint size and obtain better performance. The achievement of high efficiency was possibly obtained by optimizing the structural properties of the waveguide and the coupling angle from the SMF. The results demonstrated high efficiency within the O-band spectrum by using a wavelength of 1310 nm. Notably, at this specific wavelength, the findings indicated a coupling efficiency of −5.52 db. The proposed design of the GC consists of a uniform grating that offers improvements regarding affordability and simplicity in manufacturing compared to other GC models. For instance, using a reflector or a GC with non-uniform grooved teeth introduces challenges in fabrication and incurs higher costs. Thus, the proposed design can be useful for improving the testing abilities of the Si3N4 photonic chips used in transceiver systems.

Fabrication Challenges in Synthesizing Porous Ceramic Membrane to Effective Flue Gas Treatment

Global warming is a serious concern worldwide, while there are many contributors to rise the temperature of earth. One major source to it, is air pollution. It is of utmost importance to apply the necessary remedial actions to address the contaminants in outdoor and indoor environment. In this research a step is taken to treat flue gases, for which membrane technology is introduced. A porous ceramic membrane is synthesized from calcined porous alumina (Al2O3) and activated washed fly ash. Some other additives like starch (C6H10O5) n, binder solution along with ethyl silicate (C8H2O4Si) and a deflocculating agent carbonic acid (H2CO3), are employed. Alongside it, some of the issues are discussed which are faced during fabrication of porous ceramic membrane i.e., crakes in membrane sample, non-active reactants issue, un-even rise or fall during de-moisturization or sintering steps. Further, the membrane sample is characterized through different test including: Further, the membrane sample is characterized through different test including thermogravimetric analysis (TGA) and DTG, which shown a satisfactory results, as there is negligible percentage weight loss after 750°C. X-ray fluorescence (XRF) for fly ash portrayal and X-ray diffraction (XRD) analysis for structure assessing are conducted, which described that the fabricated membrane has a crystalline structure as like ceramic. Archimedes Principal technique is used to determine bulk density, and porosity of the membrane sample, the values are 4.484 g/cm3, and 62.5% respectively. Average pore size of 7.6 µm is find out through optical microscopy test, similarly mechanical strength is found to be 2.7 MPa. Furthermore, a pilot scale visual permeability test is performed for flue gases treatment of combusting fuel containing tyre and coal powder. The results show the compatibility of the fabricated porous ceramic membrane to be utilized for treatment of flue gases.

Microstructure and Elevated Temperature Flexure Testing of Tungsten Produced by Electron Beam Additive Manufacturing

Due to their superior high-temperature thermomechanical capabilities, sputter erosion durability, and excellent resistance to hydrogen isotopes, tungsten materials have garnered significant interest in fusion nuclear applications. However, low room-temperature ductility and complex machining strategies present significant challenges for traditional fabrication. Electron beam powder bed fusion (EB-PBF) shows promise in manufacturing pure tungsten via high thermal energy input, elevated build temperature, and a tightly controlled high-vacuum environment. This work explores the process, structure, and property relationship of pure tungsten fabricated by EB-PBF, where 99.8% relative density was achieved with reduced cracking by isolating the build substrate and optimizing the print parameter suite. Optical and electron imaging revealed that the microstructure contained equiaxed grains along the build direction, with subgrains present in all inspected grains. Flexural testing at ambient and elevated temperatures demonstrated high ductility at 900°C and flexural strength of 470 MPa at room temperature of additively manufactured tungsten.

Rapid, Large Area Fabrication of Porous Graphene Networks Using Photothermal Flash Lamp Carbonization for High Performance Supercapacitors

Graphene materials exhibit intriguing physical, chemical, and mechanical properties. Remarkably high surface area and electrical conductivity make them excellent materials for energy storage applications, especially supercapacitors. The production of graphene requires relatively long processing times, extremely high temperatures within controlled atmospheres, and/or involves multi-step reactions that present challenges for high-throughput fabrication of energy storage devices. Moreover, supercapacitor devices fabricated using graphene suffer from low areal capacitance mainly due to the tortuous path of electrolytes in accessing the bulk of the material, which limits charge storage and transport throughout the thickness of the device.We have developed an efficient photothermal route to large-scale production of few-layer graphene within milliseconds from polymers using high intensity xenon flash lamp on carbon fiber at ambient conditions. The xenon flash lamp provides large-area illumination and a wide emission band (300 nm –1100 nm) that was used to convert the polymeric material directly into few-layer graphene upon millisecond exposures. Specifically, photothermally heating of polyaniline, a rod like polymer with a large absorption cross-section in the emission spectra of xenon flash lamp, led to the formation of macroporous network as shown in Figure 1a. Characterization revealed the formation of few layer graphene ( ID/IG ratio less than 0.3) with good adhesion to the carbon fiber support, enabling the formation of devices in-situ. We investigated the influence of morphology as well as graphene quality on the energy storage capabilities of the obtained devices as shown in Figure 1b. The supercapacitor devices prepared with macroporous few-layer graphene network exhibited a superior areal capacitance of 200 mF/cm2 at 10 mV/s which is an order of magnitude higher than few layer graphene with a conventional film like structure. Also, it retained more than 70% of its capacitance even after increasing the scan rate to 100 mV/s. Moreover, large area processability enabled by this photothermal approach allowed us to easily produce graphene-derived high-performance supercapacitor devices over areas greater than 100 cm2 (Figure 1c) within a few milliseconds at ambient conditions. Hence, this work provides an energy efficient and scalable route to produce high-quality few layer graphene devices with superior energy storage capabilities. Figure 1

Role of Dopants in Fine-Tuning the Electrical and Catalytic Properties of Barium Niobate Perovskites Towards High-Temperature Electrolyzer Application

Perovskite materials are being studied for high temperature electrochemical applications such as solid oxide fuel cells (SOFC) and electrolyzers due to their tunable conductivity and catalytic activity. However, high temperature operation poses significant challenges in both fabrication and durable operation that is further complicated by the operating environment.1 We studied barium niobates with various dopants such as Fe, Ni, Ca, Y, and Mg for B site doping while Sr, K, and La are studied for A site doping. These niobates showed enhanced chemical stability in SOFC relevant conditions and catalytic activity towards methane activation. Nb4+/5+ redox couple seem to be a key reason behind this chemical stability while the size and electronegativity of the dopants affect the electrical properties.2 Catalyst exsolution is explored with dopants such as Fe, Ni, and Co under reducing conditions along with surface bound metallic nanoparticles prepared by an incipient wet synthesis method. Chemical stability of these perovskites was analyzed by an in situ TGA measurements under various gas environments followed by analysis of the powders using PXRD, XPS, SEM, and TEM methodologies.3 Methane activation properties are further analyzed in a temperature programmed reaction setup while Electrochemical properties were evaluated in a home-made setup using different electrolyte materials in the temperature range of 700°C to 900°C. Cyclic voltammetry, impedance spectroscopy, and chronoamperometry measurements coupled with continuous mass spectra analysis was utilized to diagnose any correlation between product distribution and applied potential. Our results demonstrate doped barium niobates as a promising candidate for stable operation in high temperature electrochemical applications. The presentation will discuss these results and provide a correlation between dopants and catalytic activity and chemical stability of doped barium niobate perovskites. References (1) Ramaiyan, K. P.; Denoyer, L. H.; Benavidez, A.; Garzon, F. H. Selective Electrochemical Oxidative Coupling of Methane Mediated by Sr2Fe1.5Mo0.5O6-δ and Its Chemical Stability. Commun. Chem. 2021, 4 (1), 139. https://doi.org/10.1038/s42004-021-00568-1.(2) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv. Mater. Interfaces 2022, 9 (27), 2200796. https://doi.org/10.1002/admi.202200796.(3) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Chemical Stability of BaMg0.33Nb0.67-XFexO3-δ in High Temperature Methane Conversion Environments. under communication - ECS Journal of Solid State Science and Technology.

(Invited) Rapid, Large Area Preparation of Few-Layer Graphene Films Using Xenon Flash Lamp Pyrolysis for High-Performance Structural Micro-Supercapacitors

Graphene offers excellent electrical conductivity and very high surface area, which holds great promise for energy storage applications including supercapacitors. Current preparation methods for graphene require relatively long processing times, extremely high temperatures within controlled atmospheres, and/or involve multi-step reactions that present challenges for high throughput fabrication of graphene-based energy storage devices. We report a novel photothermal route to large-scale production of graphene within milliseconds using a commercially available polymers (polybenzoxazine, polyacrylonitrile and polyaniline) and a high intensity xenon flash lamp on various substrates, including carbon fibers, at ambient conditions. The xenon flash lamp provides large-area illumination and a wide emission band (300 nm –1100 nm) that was used to convert the polymeric material directly into few layer graphene upon millisecond exposures. The precursor material is heated to extremely high temperatures in a fraction of a second – a duration that is much shorter than the timescale for thermal equilibrium. This enabled the conversion of the polymeric material into few layer graphene in air and at room temperature, and without thermally damaging the substrate. Conversion to few-layer graphene was strongly dependent on pulse energy and the local temperature which was controlled via pulse power modulation. The obtained graphene composites at optimized conditions exhibited excellent conductivity (0.1 ohm-cm) with ID/IG ratio of 0.3 (Figure 1a). Particularly, graphene derived from polyaniline resulted in the formation of macroporous network (Figure 1b) with good adhesion to the carbon fiber, all of which facilitate the transport of ions through the material. The fabricated supercapacitor devices exhibited a very high areal capacitance of 200 mF/cm2 at 10 mV/s with retention of more than 70% of their capacitance, even at scan rates up to 100 mV/s. Moreover, mechanically, and structurally stable graphene derived from polyaniline on carbon fiber was utilized for the preparation of structural energy storage devices. We assembled symmetric structural supercapacitor comprised of carbonaceous material (carbon fiber and few-layer graphene) and polymer gel electrolyte. This resulted in the preparation of large area device (40 cm2) as shown in the Figure 1c with the capacitance exceeding 2000 mF and almost complete retention of capacitance after 5000 cycles.The preparation of high-quality graphene via photothermal pyrolysis of polymer is amenable to high throughput processing, enabling large-scale production of high performance structural electrochemical energy storage devices. Figure 1

Optical leaky fin waveguide for long-range optical antennas on high-index contrast photonic circuit platforms

Long-distance light detection and ranging (LiDAR) applications require an aperture size in the order of 30 mm to project 200–300 m. To generate such collimated Gaussian beams from the surface of a chip, this work presents a novel waveguide antenna concept, which we call an “optical leaky fin antenna,” consisting of a tapered waveguide with a narrow vertical “fin” on top. The proposed structure (operating around λ=1.55 μm) overcomes fundamental fabrication challenges encountered in weak apodized gratings, the conventional method to create an off-chip wide Gaussian beam from a waveguide chip. We explore the design space of the antenna by scanning the relevant cross section parameters in a mode solver, and their sensitivity is examined. We also investigate the dispersion of the emission pattern and angle with the wavelength. The simulated design space is then used to construct and simulate an optical antenna to emit a collimated target intensity profile. Results show inherent robustness to crucial design parameters and indicate good scalability of the design. Possibilities and challenges to fabricate this device concept are also discussed. This novel antenna concept illustrates the possibility to integrate long optical antennas required for long-range solid-state LiDAR systems on a high-index contrast platform with a scalable fabrication method.

Challenge for fabrication of silk-based sustainable products based on microscopic biomimetics of hierarchical structure in native silks

Challenge for fabrication of silk-based sustainable products based on microscopic biomimetics of hierarchical structure in native silks

Graphene-based electrodes for ECG signal monitoring: Fabrication methodologies, challenges and future directions

Graphene-based electrodes for ECG signal monitoring: Fabrication methodologies, challenges and future directions

Wafer-scale floating-gate field effect transistor sensor built on carbon nanotubes film for Ppb-level NO2 detection

NO2 is served as an air pollutant and a specific biomarker for disease diagnosis, which becomes a major detection object in environmental protection and health medical fields. Transition metal dichalcogenides (TMDs) materials have attracted considerable attention for their ability to detect NO2 without heating conditions. The requirements in the above fields for the lower limit of NO2 concentration detection are as low as ppb-level, but the trace gas is difficult to cause the large electrical signal changes, which becomes the bottleneck for TMDS materials in NO2 detection. Moreover, TMDs-based conductance sensors are susceptible to humidity interference at room temperature, which also have challenges in device size, batch fabrication, and reproducibility. How to achieve miniaturization and integration of TMDs-based gas sensors will provide a boost to portable detection of NO2 in environmental protection and health medical fields. Herein, on the basis of the principle of top-gate field effect transistor (FET), a strategy of using gas-sensing materials as the floating-gate (FG) in FET sensor is proposed to realize the detection of trace gas. The channel, dielectric layer, and FG are formed by carbon nanotubes, Y2O3, and Pd/WS2 respectively. The unique amplification effect of carbon-based FET on the gas-sensing signal is utilized to achieve NO2 detection down to 20 ppb. Furthermore, visible-light-assisted detection mode is applied to the FG FET sensor, achieving stable anti-humidity property and 100% recoverability at 10%–70% RH. We expect our work can provide a significant approach to developing micro gas sensor chips for environmental detection and portable medical applications.

Methodology of fabricating 3D printing modified plastic single-layer panels with UAV positioning technology in the era of mass customization

Mass customization of prefabricated architecture is becoming increasingly crucial for developing the architectural industry. Advanced technologies such as 3D printing and unmanned aerial vehicles (UAV) has brought opportunities and challenges for traditional fabrication and construction methodology. Based on these emerging digital design tools and intelligent construction methods, this paper presents a novel methodology for fabricating single-layer 3D printing panels using UAV positioning technology, which has the potential to revolutionize the construction process and enhance the overall efficiency. This paper first provides a comprehensive review of the existing technologies in 3D printing and UAV positioning, highlighting their benefits and limitations in the context of construction applications. Next, a step-by-step process for fabricating single-layer 3D printing panels is introduced, detailing the optimal design parameters, material selection, and printing techniques. The utilization of UAV for precise positioning and alignment of the panels is then discussed, including the development of an on-site installation for accurate control. To validate the proposed method, a construction practice of the Chengdu Agricultural Expo Centre is produced o demonstrate the promising manufacturing and installation of single-layer 3D printed panels using UAV positioning technology. The results indicate that this method significantly reduces construction time, material waste, and labour costs, while also demonstrating significant customization and design flexibility.

Engineering Cardiac Tissue for Advanced Heart-On-A-Chip Platforms.

Cardiovascular disease is a major cause of mortality worldwide, and current preclinical models including traditional animal models and 2D cell culture models have limitations in replicating human native heart physiology and response to drugs. Heart-on-a-chip (HoC) technology offers a promising solution by combining the advantages of cardiac tissue engineering and microfluidics to create in vitro 3D cardiac models, which can mimic key aspects of human microphysiological systems and provide controllable microenvironments. Herein, recent advances in HoC technologies are introduced, including engineered cardiac microtissue construction in vitro, microfluidic chip fabrication, microenvironmental stimulation, and real-time feedback systems. The development of cardiac tissue engineering methods is focused for 3D microtissue preparation, advanced strategies for HoC fabrication, and current applications of these platforms. Major challenges in HoC fabrication are discussed and the perspective on the potential for these platforms is provided to advance research and clinical applications.

4d Bioprinting via Molecular Network Contraction for Membranous Tissue Fabrication.

Generation of thin membranous tissues (TMT), such as the cornea, epidermis, and periosteum, presents a difficult fabrication challenge in tissue engineering (TE). TMTs consist of several cell layers that are less than 100μm in thickness per layer. While traditional methods provide the necessary resolution for TMT fabrication, they require significant handling and incorporation of several layers is limited. Extrusion bioprinting offers precise control over deposition of different biomaterials and cell populations within the same construct but lacks the resolution to generate biomimetic TMTs. W e have developed, for the first time, a 4D bioprinting strategy that allows for the generation of cell-laden TMTs. Anionic gelatin methacrylate (GelMA) hydrogels are treated with cationic poly-L-lysine (PLL), which induces charge attraction, microscale network collapse, and macroscale hydrogel shrinking. The impact of shrinking on hydrogel properties, print resolution, and cell viability are presented. Additionally, o ur work suggests that a novel mechanism is occurring, where PLL exhibits a contractile force on GelMA and PLL molecular weight drives GelMA shrinking capabilities. Finally, w e show that this phenomenon can occur while maintaining an encapsulated cell population. These findings address a critical barrier in TE by generating macroscale tissue structures with their microscale TMT counterparts in the same print. This article is protected by copyright. All rights reserved.

A Sewing Approach to the Fabrication of Eco/bioresorbable Electronics.

Eco/bioresorbable electronics represent an emerging class of technology defined by an ability to dissolve or otherwise harmlessly disappear in environmental or biological surroundings after a period of stable operation. The resulting devices provide unique capabilities as temporary biomedical implants, environmental sensors, and related systems. Recent publications report schemes to overcome challenges in fabrication that follow from the low thermostability and/or high chemical reactivity of the eco/bioresorbable constituent materials. Here, this work reports the use of high-speed sewing machines, as the basis for a high-throughput manufacturing technique that addresses many requirements for these applications, without the need for high temperatures or reactive solvents. Results demonstrate that a range of eco/bioresorbable metal wires and polymer threads can be embroidered into complex, user-defined conductive patterns on eco/bioresorbable substrates. Functional electronic components, such as stretchable interconnects and antennas are possible, along with fully integrated systems. Examples of the latter include wirelessly powered light-emitting diodes, radiofrequency identification tags, and temporary cardiac pacemakers. These advances add to a growing range of options in high-throughput, automated fabrication of eco/bioresorbable electronics.

Covalent-organic porous framework (COF) integrated hybrid membranes for energy and environmental applications: Current and future perspectives

BackgroundThe discharging of toxic pollutants into the ecosystem is a growing concern worldwide. Every year a huge amount of various hazardous materials is released into aquatic ecosystems and air, leading to significant harm to humans and the environment. So, it is necessary to develop advanced engineered nanomaterials such as inorganic, metal organic framework (MOFs) and covalent organic framework (COFs) to protect the environment and people exposed to those harmful pollutants. Covalent organic frameworks (COFs) are porous crystalline materials known for excellent separation performance. COFs offer a large surface area, high porosity, low density, flexible molecular sieving, tunable pore size, and high stability, and are compatible with polymers to form MMMs. Furthermore, the modification of COFs by varying functional groups materials will develop high-performance membranes for gas and water treatment and fuel cell applications. MethodsThis article has discussed the crucial properties of COF materials, such as molecular sieving, hydrophilicity, hydrophobicity, framework stability, and surface charge required for membrane performance enhancement. The different strategies for COF membrane fabrication, like in-situ growth, layer-by-layer stacking, blending, etc., were also highlighted. SignificantThe COF membranes for water and wastewater treatment applications, gas separation, and fuel cells were also focused. The performance of literature reported COF membranes were discussed based on their water flux, rejection, gas permeance, selectivity factors, and proton conductivity. Modifying and designing membranes for various separation processes is done by altering the COF's structure and properties to utilize the membrane for practical applications. The fabrication challenges and utilization of COF membranes for different applications and the ways to move forward were addressed.

Broadside-Coupled Niobium Flexible Cables

We have developed fine-pitch, multilayer, superconducting wiring for routing around a ninety-degree corner terminated with wirebonding interfaces. The component-level testbed for the Advanced Telescope for High Energy Astrophysics (ATHENA) X-Ray Integral Field Unit (X-IFU) focal plane requires compact, high-density, low-crosstalk wiring fanout to connect the detectors in the focal plane array with NIST-fabricated SQUID time domain multiplexing (TDM) readout chips. The full assembly baselines two interface chips: a flexible interface chip bending around the corner and a planar silicon carrier chip. The TDM readout is indium bump-bonded to the silicon carrier and afterward the flexible chip is clipped in place and wirebonded to the detector and fanout wiring on the carrier. This assembly is repeated for each side of the hexagonal focal plane structure. As conventional commercial cables are not able to achieve the fine-pitch, low-crosstalk, superconducting wiring required, we fabricate these flexible interface chips in-house via lithographic patterning and etching of sputter deposited thin films to create broadside-coupled superconducting niobium microstrips. Within the chip, the wiring on the flexible polyimide region transitions to silicon substrate for the closely spaced wirebond pads. The Nb microstrip wiring climbing a thick polyimide sidewall presents a fabrication challenge which we shall discuss in this paper. We describe the function of these components to build an effective engineering testbed for the ATHENA X-IFU.

Additive manufacturing for Proton Exchange Membrane (PEM) hydrogen technologies: merits, challenges, and prospects

With the growing demand for green technologies, hydrogen energy devices, such as Proton Exchange Membrane (PEM) fuel cells and water electrolysers, have received accelerated developments. However, the materials and manufacturing cost of these technologies are still relatively expensive which impedes their widespread commercialization. Additive Manufacturing (AM), commonly termed 3D Printing (3DP), with its advanced capabilities, could be a potential pathway to solve the fabrication challenges of PEM parts. Herein, in this paper, the research studies on the novel AM fabrication methods of PEM components are thoroughly reviewed and analysed. The key performance properties, such as corrosion and hydrogen embrittlement resistance, of the additively manufactured materials in the PEM working environment are discussed to emphasise their reliability for the PEM systems. Additionally, the major challenges and required future developments of AM technologies to unlock their full potential for PEM fabrication are identified. This paper provides insights from the latest research developments on the significance of advanced manufacturing technologies in developing sustainable energy systems to address the global energy challenges and climate change effects.