Rapid Fabrication Research Articles

Geometrical and Optical Properties of Optical Components Manufactured by Means of Stereolithography

Additive manufacturing (AM) is a fast-growing technology that supports the rapid fabrication of prototypes. Already, employing AM technologies in early product development stages can help to accelerate the time from conceptualisation phase to the market entry. Furthermore, advances in the field of materials, such as highly transparent resins in the visible wavelength spectrum, also open application potentials for the design and fabrication of optical components. Three highly transparent resins from different suppliers are studied in this work regarding their influence on the geometrical and optical properties of additively manufactured components. The different materials were processed using a masked stereolithography 3D printer. Geometrical and optical properties of the generated test samples were analysed by means of laser scanning microscopy and spectrophotometry, respectively. A clear correlation between optical properties of the resin and the solidified samples was identified. It was further found that while spin coating does not significantly affect the geometrical properties, a strong influence on the resulting optical properties could be observed. The highest transmission properties, in the range of up to 90%, were determined for samples that were spin-coated on both surfaces. Thus, applying a spin coating operation to additively manufactured optical components is recommended for the highest transmission properties.

Towards multifunctional carbon composites: Rapid fabrication of hollow-skeleton and porous-skin composites derived from waste biomass

Towards multifunctional carbon composites: Rapid fabrication of hollow-skeleton and porous-skin composites derived from waste biomass

Nano‐Springe Enriched Hierarchical Porous MOP/COF Hybrid Aerogel: Efficient Recovery of Gold from Electronic Waste

AbstractExtraction of gold from secondary resources such as electronic waste (e‐waste) has become crucial in recent times to compensate for the gradual scarcity of the noble metal in natural mines. However, designing and synthesizing a suitable material for highly efficient gold recovery is still a great challenge. Herein, we have strategically designed rapid fabrication of an ionic crystalline hybrid aerogel by covalent threading of an amino‐functionalized metal‐organic polyhedra with an imine‐linked chemically stable covalent organic framework at ambient condition. The hierarchically porous ultra‐light aerogel featuring imine‐rich backbone, high surface area, and cationic sites have shown fast removal, high uptake capacity (2349 mg/g), and excellent selectivity towards gold sequestration. Besides, the aerogel can extract ultra‐trace gold‐ions from different terrestrial water bodies, aiming towards safe drinking water. This study demonstrates the great potential of the composite materials based on a novel approach to designing a hybrid porous material for efficient gold recovery from complex water matrices.

Scalable fabrication of freely shapable 3D hierarchical Cu-doped hydroxyapatite scaffolds via rapid gelation for enhanced bone repair

Critical-sized bone defects present a formidable challenge in tissue engineering, necessitating innovative approaches that integrate osteogenesis and angiogenesis for effective repair. Inspired by the hierarchical porous structure of natural bone, this study introduces a novel method for the scalable production of ultra-long, copper-doped hydroxyapatite (Cu-HAp) fibers, utilizing the rapid gelation properties of guar gum (GG) under controlled conditions. These fibers serve as foundational units to fabricate three-dimensional porous scaffolds with a biomimetic hierarchical architecture. The scaffolds exhibit a broad pore size distribution (1–500 μm) and abundant nanoporous features, mimicking the native bone extracellular matrix. Physicochemical characterization and in vitro assays demonstrated that the copper doping significantly enhanced osteogenic and angiogenic activities, with optimized concentrations (0.8 % and 1.2 % Cu) facilitating the upregulation of osteogenesis-related genes and proteins, as well as promoting endothelial cell proliferation. In vivo studies further confirmed the scaffolds' efficacy, with the 1.2Cu-HAp group showing a remarkable increase in bone regeneration (bone volume/total volume ratio: 35.7 ± 1.87 %) within the defect site. This research offers a promising strategy for the rapid fabrication of multifunctional scaffolds that not only support bone tissue repair but also actively accelerate the healing process through enhanced vascularization.

Geometrically engineered organoid units and their assembly for pre-construction of organ structures.

Regenerative medicine is moving from the nascent to the transitional stage as researchers are actively engaged in creating mini-organs from pluripotent stem cells to construct artificial models of physiological and pathological conditions. Currently, mini-organs can express higher-order functions, but their size is limited to the order of a few millimeters. Therefore, one of the ultimate goals of regenerative medicine, "organ replication and transplantation with organoid," remains a major obstacle. Three-dimensional (3D) bioprinting technology is expected to be an innovative breakthrough in this field, but various issues have been raised, such as cell damage, versatility of bioink, and printing time. In this study, we established a method for fabricating, connecting, and assembling organoid units of various shapes independent of cell type, extracellular matrix, and adhesive composition (unit construction method). We also fabricated kidney tissue-like structures using three types of parenchymal and interstitial cells that compose the human kidney and obtained findings suggesting the possibility of crosstalk between the units. This study mainly focuses on methods for reproducing the structure of organs, and there are still issues to be addressed in terms of the expression of their higher-order functions. We anticipate that engineering innovation based on this technique will bring us closer to the realization of highly efficient and rapid fabrication of full-scale organoids that can withstand organ transplantation.

Rapid curing dynamics of PEG-thiol-ene resins allow facile 3D bioprinting and in-air cell-laden microgel fabrication

Thiol-norbornene photoclick hydrogels are highly efficient in tissue engineering applications due to their fast gelation, cytocompatibility, and tunability. In this work, we utilized the advantageous features of polyethylene glycol (PEG)-thiol-ene resins to enable fabrication of complex and heterogeneous tissue scaffolds using 3D bioprinting and in-air drop encapsulation techniques. We demonstrated that photoclickable PEG-thiol-ene resins could be tuned by varying the ratio of PEG-dithiol to PEG norbornene to generate a wide range of mechanical stiffness (0.5-12 kPa) and swelling ratios. Importantly, all formulations maintained a constant, rapid gelation time (<0.5 s). We used this resin in biological projection microstereolithography (BioPµSL) to print complex structures with geometric fidelity and demonstrated biocompatibility by printing cell-laden microgrids. Moreover, the rapid gelling kinetics of this resin permitted high-throughput fabrication of tunable, cell-laden microgels in air using a biological in-air drop encapsulation apparatus (BioIDEA). We demonstrated that these microgels could support cell viability and be assembled into a gradient structure. This PEG-thiol-ene resin, along with BioPµSL and BioIDEA technology, will allow rapid fabrication of complex and heterogeneous tissues that mimic native tissues with cellular and mechanical gradients. The engineered tissue scaffolds with a controlled microscale porosity could be utilized in applications including gradient tissue engineering, biosensing, andin vitrotissue models.

Rapid fabrication of through-hole arrays in thin glass by femtosecond laser bursts assisted with chemical etching

A large-area vertical through-hole array in thin glass is rapidly fabricated by using femtosecond laser bursts assisted with chemical etching. By investigating the effects of the sub-pulse number and total pulse energy on the morphologies of the ablated microholes, as well as the effects of the chemical etching time and the concentration of HF acid solution on the morphologies of the through-holes, it is found that only under the condition that the upper surface of the glass microhole arrays is not ablated, but the exit is ablated by the femtosecond laser bursts with the increase of the sub-pulse number, a uniform and nearly vertical through-hole array can be obtained after etching in 5-wt% HF acid solution for 20 min. This single-step femtosecond laser bursts scanning method can significantly improve the fabrication efficiency of the ablated microhole arrays to about 18,000 microholes per second, which might provide a new technical guide for rapidly fabricating large-area vertical through-hole arrays in thin glass.

Nano-Springe Enriched Hierarchical Porous MOP/COF Hybrid Aerogel: Efficient Recovery of Gold from Electronic Waste.

Extraction of gold from secondary resources such as electronic waste (e-waste) has become crucial in recent times to compensate for the gradual scarcity of the noble metal in natural mines. However, designing and synthesizing a suitable material for highly efficient gold recovery is still a great challenge. Herein, we have strategically designed rapid fabrication of an ionic crystalline hybrid aerogel by covalent threading of an amino-functionalized metal-organic polyhedra with an imine-linked chemically stable covalent organic framework at ambient condition. The hierarchically porous ultra-light aerogel featuring imine-rich backbone, high surface area, and cationic sites have shown fast removal, high uptake capacity (2349 mg/g), and excellent selectivity towards gold sequestration. Besides, the aerogel can extract ultra-trace gold-ions from different terrestrial water bodies, aiming towards safe drinking water. This study demonstrates the great potential of the composite materials based on a novel approach to designing a hybrid porous material for efficient gold recovery from complex water matrices.

Rapid Fabrication of Graphene Fibers and Fiber-Based Thermistors for Wearable Devices

Rapid Fabrication of Graphene Fibers and Fiber-Based Thermistors for Wearable Devices

Programmable and rapid fabrication of complex-shape ceramics

Shaping of ceramics is crucial. Current techniques cannot easily and rapidly shape ceramics without weakening their properties, especially for piezoceramics. We present an ultrafast ceramic shaping method that leverages thermomechanical fields to deform and sinter ceramic powder compacts into complex-shaped ceramics. The shape-forming process hinges on: (1) the implementation of a precise thermal field to activate optimal deformability, and (2) the application of sufficient mechanical loads to guide deformation. We employ a programmable carbon-felt Joule heater that concurrently function as mechanical carriers, effectively transferring applied loads to the ceramic powder compacts. Using this ultrafast shaping and sintering (USS) method, we fabricate barium titanate (BT) piezoceramics in twisted shape, arch shape and with micropatterns. The USS method is energy-friendly (requiring approximately 1.06 kJ mm−3) and time-efficient (in several minutes level). Overall, the USS method offers an effective solution for shaping ceramics and extends them to 3D geometries with enhanced versatility.

Intrinsically Thermally Degradable Microstructures Fabricated by Photodimerization in Rapid 3D Laser Printing

AbstractClassical photoresists utilized in direct laser writing (DLW) rely on photoinitiators and radical polymerization mechanisms to induce the cross‐linking process. Herein, a simple initiator‐free photoresist is introduced that enables the rapid fabrication of intrinsically thermally degradable 3D microstructures via DLW. The reported photoresist exploits the [2 + 2] photo‐dimerization reaction of a multifunctional monosubstituted thiomaleimide compound while harvesting on‐demand microstructure degradation through the intrinsic thermally reversible nature of the photocrosslinks. The photoresist exceeds attainable DLW printing speeds for non‐chain growth resins, readily attaining 1500 µm s−1 and up to 5000 µm s−1, making it a promising system to compete with traditional photo‐initiator containing resists while introducing on‐demand post‐printing degradability.

Vortex-enhanced jet impingement and the role of impulse generation rate in heat removal using additively manufactured synthetic jet devices

This article presents an approach to the design and fabrication of synthetic jet devices (SJDs) using rapid prototyping via additive manufacturing, marking the first study to employ this method for such devices. This manufacturing technique empowers researchers with complete design freedom, enabling the production of ultra-thin SJDs—as thin as 4 mm—without mechanical fasteners and facilitating the rapid fabrication of multiple devices with varying geometries. To showcase the potential of this method, SJDs with conical and cylindrical cavities and orifices ranging from 1.6 mm to 7 mm were designed, fabricated, and tested.These devices achieved air jet exit velocities exceeding 106 m/s using a single piezoelectric diaphragm—among the highest reported in the literature—validating the effectiveness of this manufacturing approach. This high jet velocity is significant for practical applications requiring efficient thermal management, such as cooling high-power-density electronics, where compact and energy-efficient solutions are essential. Beyond achieving high velocities, it was revealed that maximizing jet velocity alone is not always optimal for heat removal. The hydrodynamic impulse generation rate was introduced as a more significant factor influencing heat transfer performance. By fabricating and testing multiple SJDs with different geometries, it was demonstrated that the impulse generation rate, which accounts for both jet velocity and flow rate, better correlates with enhanced heat transfer capabilities than jet velocity alone. This insight addresses an often-overlooked parameter in SJD design and has substantial implications for optimizing heat removal performance. Moreover, lumped element modeling, tuned solely on diaphragm deflection behavior, accurately predicted device performance and was validated using a hotwire anemometer. This model effectively characterizes center-axis orifice devices and confirms its applicability to thin-cavity designs, providing a valuable tool for future SJD development. Despite moderate volume flow rates (0.2 to 0.8 m3/h), the fabricated SJDs delivered significant improvements in heat transfer. Compared to natural convection, these devices achieved over 13 times greater heat removal rates, with an average heat transfer coefficient exceeding 120 W/m2·K over a 30 mm × 30 mm heated surface. These findings demonstrate the practicality and effectiveness of vortex-enhanced synthetic jet impingement for targeted and efficient cooling of localized hot spots. This approach offers multiple advantages over traditional rotary cooling systems like fans, including increased reliability, lower profile, while consuming less than 100 mW. The ability to rapidly prototype and optimize SJDs using additive manufacturing accelerates research and development in this field, paving the way for advanced thermal management solutions in real-world applications.

Revealing the improved thermoelectric performances of (BiSb)2Te3 alloy through rapid solidification of cold-water assisted water atomization approach

In the industrialization of high-efficiency (BiSb)2Te3-based bulk thermoelectric materials, the cost-effectiveness, and rapid fabrication methods are of considerable interest; herein, mass production of nearly 2 Kg/min of desired Bi0.5Sb1.5Te3 powders with greater powder uniformity was successfully manufactured using water atomization than that of any other routes. In particular, the solidification of thermoelectric metal powders using different water source temperatures has not yet been studied. Hence, for the first time, we have reported the influence of the solidification rate on the microstructural and thermoelectric performances of cold and hot water-assisted p-type Bi0.5Sb1.5Te3 alloys using the water atomization method. The rapid solidification using low temperature (278 K) cold water assisted- Bi0.5Sb1.5Te3 atomized powders produces smaller particle sizes with a greater degree of lattice defects decreasing the lattice thermal conductivity (κL) significantly compared to the hot water source (359 K). Thus, a notable decrement in the lattice thermal conductivity (κL) of 0.47 W/m.K. and the corresponding total thermal conductivity (κ) at 0.93 W/m.K. at 400 K was obtained for the cold water-Bi0.5Sb1.5Te3 owing to the fine distributions of grains and extensively larger fractions of twin boundary density in the misorientation angle from 80 to 92°. As a result, the cold water-Bi0.5Sb1.5Te3 shows a substantially maximum figure of merit, ZTmax. of 1.37 at 400 K compared to hot water-Bi0.5Sb1.5Te3 (≈1.21). Hence, the cold water-assisted atomization approach would be beneficial for the large production of thermoelectric materials with improved thermoelectric performances, and it is very promising to be scalable in the commercialization of large-scale devices.

High-throughput Generation of Collagen Microbeads for 3D Cell Culture and Extracellular Vesicle Production.

Collagen type I, a fundamental component of natural extracellular matrices across species, is an attractive material for the development of tissue engineering constructs. Nevertheless, the poor mechanical properties and thermal instability hinder its use for specific construction of 3D cultures and 3D printing. In this study, we present a microfluidic high-throughput approach for producing high-quality and uniform collagen microbeads without introducing any chemical modification. We achieved rapid and uniform collagen droplet fabrication with sizes spanning from 50 μm to 1200 μm in a production rate of up to 10000 droplets per minute. The resulting collagen microbeads can serve as numerous microbioreactors which are suspended in the culture medium without precipitation and are ideal for 3D cell growth. We demonstrated excellent cell compatibility, facilitating cell attachment and proliferation, as well as promoting extracellular vesicle secretion from collagen microbeads. This technology is facile and versatile for high throughput 3D cell culture, heterogeneous tissue modeling, and extracellular vesicle production, which is essential in drug delivery and drug screening.

Rapid-printed Three-dimensional Models for Craniomaxillofacial Trauma.

Advances in surgical planning and 3-dimensional (3D) printing have benefitted the field of craniomaxillofacial surgery by allowing visualization of patient anatomy in settings of otherwise restricted surgical fields. Long 3D print times limit the usability of surgical planning workflows in acute trauma reconstruction. We sought to identify variables affecting print time and produce rapid-printed models with sufficient quality for prebending osteosynthesis plates. Three-dimensional printing variables, including resolution, print orientation, and region of interest cropping, were optimized on a single mandibular and midface fracture model to maximize print time efficiency. Five mandibular and 5 midface fractures were printed both in the high-resolution and time-efficient protocol. Fixation plates were contoured to fit the optimized models and computed tomography scan. Distances and volumes between the fracture surface and plate were computed. High-resolution mandible models were printed in 7.47 hours and maxillae in 7.53 hours. Optimized models were printed in 0.93 and 1.07 hours, respectively. Cropping to regions of interest, rotating the model, and decreasing print resolution significantly reduced print time. The difference (optimized versus high resolution) in distance between the plate and model averaged 0.22 and 0.34 mm for mandibles and maxillae; the air space volume differed by 1.39 and 0.90 mm3, respectively. Adjusting size, resolution, and position on the printing platform allows rapid fabrication of 3D models for surgical reconstruction without sacrificing surface quality. These edits reduce printing time, enabling the implementation of 3D-printing workflows for surgical planning in acute craniomaxillofacial trauma settings.

Effect of Al2O3-SiO2 mass ratio and sintering temperature on the properties of water-soluble salt-based ceramic cores formed by binder jetting

Binder Jetting (BJ) technology, known for its cost-effectiveness and efficiency, is widely used for the rapid fabrication of complex ceramic cores. However, fabricating high-strength and water-soluble ceramic cores via BJ technology is particularly challenging due to the balance between mechanical properties and water solubility. In this work, BJ technology was employed to fabricate high-strength and water-soluble salt-based ceramic cores (SCC) regulated synergistically by Al2O3 and SiO2. The effects of the mass ratio of Al2O3 to SiO2 (A/S) and sintering temperature on the properties of Na2CO3-based samples were investigated, with detailed analyses of the regulation mechanism through thermodynamic, kinetic, and microstructural examinations. The results indicated that when A/S was 1:4, the bending strength of samples sintered at 760 °C for 60 min reached up to 62.38 MPa with good water collapsibility. Thermodynamic and kinetic analyses revealed that the formation of Na2SiO3 was prioritized over NaAlO2, and the content of Na2SiO3 as well as the proportion of liquid phase increased with the decrease of A/S and the increase of sintering temperature, resulting in the increase of sample density, as confirmed by microstructure analyses, which was the main strengthening mechanism of samples. Ultimately, complex-structure SCC samples were successfully fabricated. This study provides an insightful method for fabricating high-strength and water-soluble ceramic cores, with significant potential applications in the casting industry.

Mechanical property of SiC whisker reinforced CaZr4(PO4)6 ceramics fabricated by fast hot pressure sintering

The poor mechanical properties of low thermal expansion CaZr4(PO4)6 (CZP) ceramics hinder its extreme high temperature applications. In this paper, to acquire CZP-based composite with combination of excellent mechanical properties and low thermal expansion, SiC whisker (SiCw)-dispersed CZP ceramics were fabricated using fast hot pressure sintering (FHP). The effects of varying weight percentages of SiCw and FHP processing parameters on the sintering behavior, crystal structure, microstructure and properties of CZP ceramics were systematically investigated. SiCw was nonreactive with the CZP matrix and the two phases coexisted stably. Compared with the normal-pressure sintering ceramics, the composites prepared by FHP technique exhibited increased densification. Importantly, the addition of SiCw remarkably improved the mechanical properties of FHP-prepared composites, demonstrating superior flexural strength and fracture toughness of 124 MPa and 3.72 MPa m1/2, respectively, considerably higher than that of pure CZP ceramics. The several toughing mechanisms arising from fibers, such as crack bridging, crack deflection and crack branching, accounted for the improved fracture toughness. Furthermore, the CZP-SiCw ceramics remained a low thermal expansion property, with an average thermal coefficient expansion of 1.47 × 10−6/°C. The strategy regarding FHP technology combined with appropriate incorporation of SiCw opens a pathway for rapid fabrication of high-performance NZP-type ceramics.

Rapid preparation of Cu(111) foil with large single-crystal grains through a graphene induction and contactless annealing method

There is a growing interest in preparing large-size Cu(111) foil for achieving high performance in various applications. In this work, a simple two-step method using graphene induction and contactless annealing was designed to rapidly prepare Cu(111) foil with large single-crystal grains. The graphene film grown on the Cu surface in the first step by chemical vapor deposition serves as a template for the orientation transition of the Cu foil in a subsequent high-temperature annealing. The (111) orientation transformation of the entire Cu foil was achieved within 20 min with single-crystal grains in size of above 30 cm2, and the corresponding speed is ten times higher than that prepared in traditional annealing process. This work provides a facile and rapid fabrication approach for preparing Cu(111) foil with large grains.

Dynamic interface printing

Additive manufacturing is an expanding multidisciplinary field encompassing applications including medical devices1, aerospace components2, microfabrication strategies3,4 and artificial organs5. Among additive manufacturing approaches, light-based printing technologies, including two-photon polymerization6, projection micro stereolithography7,8 and volumetric printing9–14, have garnered significant attention due to their speed, resolution or potential applications for biofabrication. Here we introduce dynamic interface printing, a new 3D printing approach that leverages an acoustically modulated, constrained air–liquid boundary to rapidly generate centimetre-scale 3D structures within tens of seconds. Unlike volumetric approaches, this process eliminates the need for intricate feedback systems, specialized chemistry or complex optics while maintaining rapid printing speeds. We demonstrate the versatility of this technique across a broad array of materials and intricate geometries, including those that would be impossible to print with conventional layer-by-layer methods. In doing so, we demonstrate the rapid fabrication of complex structures in situ, overprinting, structural parallelization and biofabrication utility. Moreover, we show that the formation of surface waves at the air–liquid boundary enables enhanced mass transport, improves material flexibility and permits 3D particle patterning. We, therefore, anticipate that this approach will be invaluable for applications where high-resolution, scalable throughput and biocompatible printing is required.

Customized Preparation of Heat-Resistant Fully Flexible Sensors Based on Coaxial 3D Printing.

The conventional behavior recognition strategy for wearable sensors used in high-temperature environments typically requires an external power supply, and the manufacturing process is cumbersome. Herein, we present a rational design strategy based on fully flexible printable materials and a customized device-manufacturing process for skin-conformable triboelectric nanogenerator sensors. In detail, using high temperature-resistant ink and 3D printing technology to manufacture a coaxial triboelectric nanogenerator (C-TENG) sensor, the C-TENG exhibits high stretchability (>400%), a wide working range (>250 °C), and high output voltage (>100 V). The C-TENG can be worn on various parts of the human body, providing a robust skin-device interface that recognizes diverse human behaviors. Using machine learning algorithms, behaviors such as walking, running, sitting, squatting, climbing stairs, and falling can be identified, achieving 100% behavior recognition accuracy through the selective input and optimization of an appropriate dataset. This paper provides a research perspective for the customization, extension, and rapid fabrication of heat-resistant, fully flexible TENGs.