Advances in Additive Manufacturing

Catalytic biomass valorization is crucial to reduce reliance on fossil resources and mitigate environmental impacts; however, the majority of chemical manufacturing still relies on conventional catalysts. Here, the authors review the potential of 3D-printed catalysts in biomass conversion, highlighting recent advances and their implications for scalable, cost-effective green chemistry.

Vat-polymerization 3D printing (3DP) enables the high speed printing of precise and intricate 3D models, yet it inevitably produces highly crosslinked polymers that are not easily degradable or recyclable. Here, the author highlights recent work that realizes the formation of fully degradable polymers based on organocatalytic vat-ring-opening photopolymerization 3DP.

Additive manufacturing has emerged as a powerful approach for achieving properties that are not possible in conventionally processed alloys. This Perspective provides a state-of-art overview of the use of operando x-ray techniques for understanding solidification dynamics and melt pool behavior in additive processes.

Within the field of additive manufacturing, direct sound printing is limited to a voxel-by-voxel printing. Here, the authors overcome this limitation with a holographic direct sound printing technique in which the information printed part is stored in an acoustic hologram and the printing material polymerizes instantly therefore improving the printing speed and allowing to print multimaterial objects even behind optically non-transparent media.

3D printing offers significant advantages in creating customized electrode structures with enhanced catalytic performance. Here, the authors employ a combination of 3D printing and conformal carbonization of ionic liquids to engineer porous carbonaceous electrodes with boron, phosphorus and nitrogen dopants, achieving enhanced electrocatalytic activity for CO₂ conversion into syngas with a controllable H₂:CO molar ratio.

Centrifugation of aqueous dispersions of hybrid polyoxometalate nanosheets is used to create inks for the 4D printing of polyoxometalate hydrogels, exhibiting complex geometries and shape reconfigurability.

Liquid crystal elastomers have potential as 4D-printing actuators, but it is difficult to achieve complex shape changes in structures. Here, the authors report a 4D-printing strategy that combines vat polymerization-based 3D printing with a two-stage UV-curable resin.

Current electronic skin technologies struggle with the selective detection of multiple stimuli, limiting their reliability in dynamic environments. Here, a double network granular organogel inspired by frog deep eutectic solvent chemistry is developed, enabling simultaneous detection of mechanical, thermal, and humidity changes.

Complex, fibrous architectures are essential to the function of engineered tissues, but precisely replicating anatomical fiber structures remains difficult. Meghan Griffin, Spencer Bertram, and colleagues present NAATIV3, a framework that leverages medical imaging data for anatomically-accurate 3D bioprinting.

Yuvraj Maphrio Mao and colleagues evaluated 3D-printed microbial fuel cells (MFCs) with fiber electrodes for underwater energy harvesting at different depths in lake water and artificial seawater under stagnant and aerated conditions. Results highlight the influence of oxygen transfer, depth, and hydrodynamic conditions on MFC efficiency, demonstrating reliable operation for self-powered underwater sensing systems

3D printing of concrete is promising for the manufacture of bespoke structures, but the high cement component leads to large carbon dioxide emissions. Here, climate-positive biochar is shown to decrease the carbon footprint of 3D printed concrete, while improving its pumpability, extrudability, and buildability

The demand for high-strength materials to enhance energy efficiency drives research into additive manufacturing and precipitation strengthening of high entropy alloys. Here, the authors investigate the low-cycle fatigue behavior of an Al-Co-Cr-Fe-Ni-Ti alloy, revealing impressive fatigue life and stress profiles, highlighting its potential for reliable structural applications.

Current additive manufacturing materials often suffer from poor stability, limited shape recovery, and insufficient mechanical properties. Here the authors develop a photopolymerizable resin with stiffness-deformability synergy and spatiotemporal shape memory capabilities.

Creating multimaterial objects through vat photopolymerization is challenging due to difficulty transitioning between liquid resins and processing incompatibility between material classes. Here the authors develop infusion multimaterial actinic spatial control additive manufacturing, which uses dual wavelength light projection to create distinct material regions that can be selectively infused with a variety of organic and metallic materials.

Arup Neogi and colleagues introduce an in-situ ultrasound monitoring system designed to assess the real-time printing quality of alginate-gelatin hydrogel. The findings show an instantaneous monitoring process, a potential alternative to layer-by-layer monitoring.

Pawel Mieszczanek and colleagues design a machine learning-based approach to improve 3D printing processes based on melt electrowriting. They present a closed-loop control framework that is based on data-driven models and enables them to monitor the melt electrowriting operations in real time in order to improve reproducibility.