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Abstract Polycrystalline yttrium aluminum garnet (YAG) ceramic doped with neodymium (Nd), referred to as Nd:YAG, is widely used in solid‐state lasers. However, conventional powder metallurgy methods suffer from expenses, time consumption, and limitations in customizing structures. This study introduces a novel approach for creating Nd:YAG ceramics with 3D free‐form structures from micron (∼70 µm) to centimeter scales. Firstly, sol‐gel synthesis is employed to form photocurable colloidal solutions. Subsequently, by utilizing a home‐built micro‐continuous liquid interface printing process, precursors are printed into 3D poly(acrylic acid) hydrogels containing yttrium, aluminum, and neodymium hydroxides, with a resolution of 5.8 µmpixel⁻¹at a speed of 10 µm s⁻¹. After the hydrogels undergo thermal dehydration, debinding, and sintering, polycrystalline Nd:YAG ceramics featuring distinguishable grains are successfully produced. By optimizing the concentrations of the sintering aids (tetraethyl orthosilicate) and neodymium trichloride (NdCl₃), the resultant samples exhibit satisfactory photoluminescence, emitting light concentrated at 1064 nm when stimulated by a 532 nm laser. Additionally, Nd:YAG ceramics with various 3D geometries (e.g., cone, spiral, and angled pillar) are printed and characterized, which demonstrates the potential for applications, such as laser and amplifier fibers, couplers, and splitters in optical circuits, as well as gain metamaterials or metasurfaces. 

Thiol-acrylate photoresin containing dynamic disulfide bonds undergoes wavelength-selective photopolymerization under greenvs.UV light to produce a degradable step-growth networkvs.permanent chain-growth network. 

Abstract Functionally gradient materials emulate nature's ability to seamlessly blend properties through variations in material composition, unlocking advanced engineering applications such as biomedical devices and high‐performance composites. Additive manufacturing, particularly stereolithography, enables sophisticated 3D geometries with diverse materials. However, current stereolithography‐based multi‐material 3D printing is constrained by time‐intensive material switching and compromised interfacial properties. To overcome these challenges, we present dynamic fluid‐assisted micro continuous liquid interface production (DF‐µCLIP), a high‐speed multi‐material 3D printing platform that integrates varying compositions in a fully continuous fashion. By utilizing the polymerization‐free “dead zone”, vliquid resins are seamlessly replenished within a resin bath equipped with dynamic fluidic channels and a synchronized material supply system. DF‐µCLIP achieves ultra‐fast printing speeds of 90 mm/hour with 7.4 µ m pixel‐1 resolution while enabling on‐the‐fly material transitions. This strategy enhances mechanical strength at multi‐material interface through entangled polymer networks and promotes seamless material transitions between distinct materials ilike fragile hydrogels and rigid polymers, addressing interfacial failure caused by mismatch of swelling behavior. Additionally, dynamic material replenishment with real‐time composition control enables continuous gradient printing instead of the conventional step‐wise controlled gradient. Demonstrations include polymers with gradient color transitions and gradient carbon nanotube (CNT) composites with seamlessly varying conductivity.