Three-dimensional printing of photonic colloidal glasses into objects with isotropic structural color.

Structural color is frequently exploited by living organisms for biological functions and has also been translated into synthetic materials as a more durable and less hazardous alternative to conventional pigments. Additive manufacturing approaches were recently exploited for the fabrication of exquisite photonic objects, but the angle-dependence observed limits a broader application of structural color in synthetic systems. Here, we propose a manufacturing platform for the 3D printing of complex-shaped objects that display isotropic structural color generated from photonic colloidal glasses. Structurally colored objects are printed from aqueous colloidal inks containing monodisperse silica particles, carbon black, and a gel-forming copolymer. Rheology and Small-Angle-X-Ray-Scattering measurements are performed to identify the processing conditions leading to printed objects with tunable structural colors. Multimaterial printing is eventually used to create complex-shaped objects with multiple structural colors using silica and carbon as abundant and sustainable building blocks.

Publisher Correction: Architectured ZnO-Cu particles for facile manufacturing of integrated Li-ion electrodes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Architectured ZnO-Cu particles for facile manufacturing of integrated Li-ion electrodes.

Designing electrodes with tailored architecture is an efficient mean to enhance the performance of metal-ion batteries by minimizing electronic and ionic transport limitations and increasing the fraction of active material in the electrode. However, the fabrication of architectured electrodes often involves multiple laborious steps that are not directly scalable to current manufacturing platforms. Here, we propose a processing route in which Cu-coated ZnO powders are directly shaped into architectured electrodes using a simple uniaxial pressing step. Uniaxial pressing leads to a percolating Cu phase with enhanced electrical conductivity between the active ZnO particles and improved mechanical stability, thus dispensing the use of carbon-based additives and polymeric binders in the electrode composition. The additive-free percolating copper network obtained upon pressing leads to highly loaded integrated anodes displaying volumetric charge capacity 6-10 fold higher than Cu-free ZnO films and that matches the electrochemical performance reported for advanced cathode structures. Achieving this high charge capacity using a readily available pressing tool makes this approach a promising route for the facile manufacturing of high-performance electrodes at large industrial scales.

Bio-inspired self-shaping ceramics.

Shaping ceramics into complex and intricate geometries using cost-effective processes is desirable in many applications but still remains an open challenge. Inspired by plant seed dispersal units that self-fold on differential swelling, we demonstrate that self-shaping can be implemented in ceramics by programming the material's microstructure to undergo local anisotropic shrinkage during heat treatment. Such microstructural design is achieved by magnetically aligning functionalized ceramic platelets in a liquid ceramic suspension, subsequently consolidated through an established enzyme-catalysed reaction. By fabricating alumina compacts exhibiting bio-inspired bilayer architectures, we achieve deliberate control over shape change during the sintering step. Bending, twisting or combinations of these two basic movements can be successfully programmed to obtain a myriad of complex shapes. The simplicity and the universality of such a bottom-up shaping method makes it attractive for applications that would benefit from low-waste ceramic fabrication, temperature-resistant interlocking structures or unusual geometries not accessible using conventional top-down manufacturing.