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Additive manufacturing using light is commonly constrained by serial voxel-by-voxel or layer-by-layer processing, which fundamentally limits fabrication speed and scalability. Here, we introduce a single-exposure holographic three-dimensional (3D) printing approach that synthesizes an entire volumetric dose distribution optically in one step. The method combines inverse-designed microstructured phase masks with photopolymer resins engineered for controlled optical absorption. By precisely tailoring the phase-mask topography, we generate arbitrary 3D light-intensity distributions within the resin, including intentionally encoded dark regions that define hollow internal features. Simultaneously, the resin formulation is designed to balance optical penetration with sufficient local energy deposition to achieve high-fidelity polymerization throughout the volume. Using this approach, millimeter-scale architectures comprising more than 10⁶addressable voxels are fabricated in a single 7.5-second exposure, corresponding to a volumetric throughput of ∼1 cubic millimeters per second (>10⁵voxels per second). The demonstrated performance is presently limited by resin kinetics and illumination geometry rather than by the phase-mask framework itself. Because the volumetric information capacity scales with the space-bandwidth product of the phase mask, this approach provides a clear pathway toward substantially higher throughput, enabling scalable fabrication of micro-optical components, biomedical scaffolds, and other precision-engineered mesoscale systems. 

For semicrystalline polyolefin thermoplastics, the balance between interconnected ordered crystalline and disordered amorphous regions is paramount to their performance and processability. However, contemporary manufacturing strategies, from injection molding to three-dimensional (3D) printing, result in monolithic objects, unable to spatially encode crystallinity. We develop a light-based approach for fabricating mechanically robust polyolefin thermoplastics with microscopic control over crystallinity in 3D space. Light dosage governs polymer stereochemistry giving access to a continuum of materials, from strong rigid plastics, such as high-density polyethylene, to more extensible materials akin to low-density polyethylene, all at the flick of a switch. Leveraging this finding in lithographic grayscale 3D printing enables rapid multimaterial fabrication with voxel-level control over optical and mechanical properties, opening avenues in information storage, soft robotics, and energy damping. 

ABSTRACT Ring‐opening metathesis polymerization (ROMP) offers a rapid, mild, and controlled route to prepare block copolymers via sequential monomer addition, where the number of blocks equates to the number of additions. However, block extension is hampered once control is lost, which can occur from cross‐metathesis and polymer precipitation during growth, precluding the ability to make certain functional triblock copolymers via unidirectional chain‐growth. Middle‐out growth from a bifunctional initiator cuts the number of additions in ~half, which has been extensively leveraged for controlled radical polymerizations but remains scarce for ROMP. Herein, a novel bifunctional Hoveyda‐Grubbs type ruthenium‐alkylidene initiator is presented and systematically examined for its use in ROMP of cyclic olefin monomers. The initiator is air‐stable, provides polymers with narrow molecular weight distributions (Đ < 1.20) and enables the preparation of functional ABA triblock and ABABA pentablock copolymers. Exemplars include norbornene‐based thermoplastic elastomers that are soft yet strong, and those that contain outer blocks from low ring strain cyclic olefins, namelycis‐cyclooctene to form poly(cyclooctene) that readily undergoes cross‐metathesis and cyclooctatetraene to form (semi)conductive yet poorly soluble poly(acetylene). This platform represents a valuable synthetic tool for the rapid generation of functional block copolymers with potential applications in soft robotics and electronics. 

Abstract The utility of visible light for 3D printing has increased in recent years owing to its accessibility and reduced materials interactions, such as scattering and absorption/degradation, relative to traditional UV light‐based processes. However, photosystems that react efficiently with visible light often require multiple molecular components and have strong and diverse absorption profiles, increasing the complexity of formulation and printing optimization. Herein, a streamlined method to select and optimize visible light 3D printing conditions is described. First, green light liquid crystal display (LCD) 3D printing using a novel resin is optimized through traditional empirical methods, which involves resin component selection, spectroscopic characterization, time‐intensive 3D printing under several different conditions, and measurements of dimensional accuracy for each printed object. Subsequent analytical quantification of dynamic photon absorption during green light polymerizations unveils relationships to cure depth that enables facile resin and 3D printing optimization using a model that is a modification to the Jacob's equation traditionally used for stereolithographic 3D printing. The approach and model are then validated using a distinct green light‐activated resin for two types of projection‐based 3D printing. 

Spatially synthesizing stiff and elastic domains from a single monomer forms robust synthetic plastics.