Voxel-based 3D printing bridges the gap between digital information representation and physical material composition.

Three-dimensional (3D) printing technologies are increasingly used to convert medical imaging studies into tangible (physical) models of individual patient anatomy, allowing physicians, scientists, and patients an unprecedented level of interaction with medical data. To date, virtually all 3D-printable medical data sets are created using traditional image thresholding, subsequent isosurface extraction, and the generation of .stl surface mesh file formats. These existing methods, however, are highly prone to segmentation artifacts that either overor underexaggerate the features of interest, thus resulting in anatomically inaccurate 3D prints. In addition, they often omit finer detailed structures and require time-and labor-intensive processes to visually verify their accuracy. To circumvent these problems, we present a bitmap-based multimaterial 3D printing workflow for the rapid and highly accurate generation of physical models directly from volumetric data stacks. This workflow employs a thresholding-free approach that bypasses both isosurface creation and traditional mesh slicing algorithms, hence significantly improving speed and accuracy of model creation. In addition, using preprocessed binary bitmap slices as input to multimaterial 3D printers allows for the physical rendering of functional gradients native to volumetric data sets, such as stiffness and opacity, opening the door for the production of biomechanically accurate models.

Significant efforts exist to develop living/non‐living composite materials—known as biohybrids—that can support and control the functionality of biological agents. To enable the production of broadly applicable biohybrid materials, new tools are required to improve replicability, scalability, and control. Here, the Hybrid Living Material (HLM) fabrication platform is presented, which integrates computational design, additive manufacturing, and synthetic biology to achieve replicable fabrication and control of biohybrids. The approach involves modification of multimaterial 3D‐printer descriptions to control the distribution of chemical signals within printed objects, and subsequent addition of hydrogel to object surfaces to immobilize engineered Escherichia coli and facilitate material‐driven chemical signaling. As a result, the platform demonstrates predictable, repeatable spatial control of protein expression across the surfaces of 3D‐printed objects. Custom‐developed orthogonal signaling resins and gene circuits enable multiplexed expression patterns. The platform also demonstrates a computational model of interaction between digitally controlled material distribution and genetic regulatory responses across 3D surfaces, providing a digital tool for HLM design and validation. Thus, the HLM approach produces biohybrid materials of wearable‐scale, self‐supporting 3D structure, and programmable biological surfaces that are replicable and customizable, thereby unlocking paths to apply industrial modeling and fabrication methods toward the design of living materials.

Construction is a labor-intensive industry that relies on dependent processes being completed in series. Redesigning fabrication processes to allow for parallelization and replacing workers with mobile multi-robot construction systems are strategies to expedite construction, but they typically require extensive supporting infrastructure and strictly constrain fabricable designs. Here we present Fiberbots, a platform that represents a step towards autonomous, collaborative robotic fabrication. This system comprises a team of identical robots that work in parallel to build different parts of the same structure up to tens of times larger than themselves from raw, homogeneous materials. By winding fiber and resin around themselves, each robot creates an independent composite tube that it can climb and extend. The robots' trajectories are controlled to construct intertwining tubes that result in a computationally-derived woven architecture. This end-to-end system is scalable, allowing additional robots to join the system without substantially increasing design complexity or fabrication time. As an initial demonstration of system viability, a structural case study was performed. The robots constructed a 4.5 meter tall tubular composite structure in an outdoor environment in under 12 hours. While further improvements must be made before this can be used in industry or in truly cooperative settings, this is the largest known demonstration of on-site construction with multiple, homogeneous mobile robots. This work offers a scalable step forward in autonomous, site-specific fabrication systems.

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