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Despite lower hardness, stiffness, and resistance to harsh environments, heavy metallic parts and soft polymer-based composites are often preferred to ceramics because they offer higher resilience. By contrast, highly mineralized biomaterials combine these properties through hierarchical and heterogeneous architecture. Reproducing these internal designs into synthetic highly mineralized materials would therefore widen their range of application. To this aim, external fields have been used to control the orientation and position of microparticles and build complex architectures. This approach is compatible with most manufacturing processes and provides large flexibility in design. Here, I present an overview of these processes and describe how they can augment the properties of the materials produced. Theoretical and experimental descriptions are detailed to determine the strengths and limitations of each technique. With this knowledge, potential areas of improvement and future research directions will lead to the creation of highly mineralized materials with unprecedented functionalities.

Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture. An additive manufacturing technique combining an aqueous-based slip-casting process with magnetically directed particle assembly makes complex-shaped heterogeneous composites with tunable local microstructure and composition.

To get nanoscopic and microscopic details, compression, tensile, or crack propagation tests can also be conducted inside a scanning electron microscope (SEM). After calibration procedures to correct for thermal expansion of the device itself, control tests were done using standard specimens made of carbon steel. [...]the setup was used to stretch at 1150°C a single-crystal Ni superalloy specimen with a notch on its side.

Robots and artificial machines have been captivating the public for centuries, depicted first as threats to humanity, then as subordinates and helpers. In the last decade, the booming exposure of humans to robots has fostered an increasing interest in soft robotics. By empowering robots with new physical properties, autonomous actuation, and sensing mechanisms, soft robots are making increasing impacts on areas such as health and medicine. At the same time, the public sympathy to robots is increasing. However, there is still a great need for innovation to push robotics toward more diverse applications. To overcome the major limitation of soft robots, which lies in their softness, strategies are being explored to combine the capabilities of soft robots with the performance of hard metallic ones by using composite materials in their structures. After reviewing the major specificities of hard and soft robots, paths to improve actuation speed, stress generation, self-sensing, and actuation will be proposed. Innovations in controlling systems, modeling, and simulation that will be required to use composite materials in robotics will be discussed. Finally, based on recently developed examples, the elements needed to progress toward a new form of artificial life will be described.

[...]a resolution down to 100 nm can be attained. [...]when suspended in water in the presence of hydrogen peroxide, a catalytic reaction occurred that liberated oxygen and water and caused the propulsion. [...]sonication detached the particles from the substrate and centrifugation was used to concentrate them.

In this context, in a study published in a recent issue of Science Advances (doi:10.1126/sciadv.aat4253), an international collaborative team led by Rόisín Owens from the University of Cambridge reports the development of a 3D tubular strategy to host and monitor growth of cells in 3D. [...]the morphology and number of the cells was monitored by fluorescence microscopy to determine the origin of the changes in electrical conductivity. In the future, Owens’s team will perform electrical stimulation experiments with various cell types, including electroactive cells, and study the effect of various compounds on the fully formed tissues. (a) Three-dimensional T-shaped tubistor in an 8-cm-diameter petri dish, with (b) the electrically conductive porous scaffold placed inside, (c) its microstructure, and (d) with green fluorescent cells.

Natural materials present sustainable opportunities in architectural design, but often lack the aesthetic controllability associated with synthetic alternatives. This research explores the bio-aesthetic potential of mycelium-bound composites (MBCs) cultivated from Ganoderma Steyaertanum (Reishi mushroom), focusing on how external stimuli and surface treatments influence material expression. This investigation was carried out through interdisciplinary collaboration involving design, architecture, and material science. Two post-demolding surface treatment strategies were applied to MBC samples: ‘Delayed Growth‘ and ‘Accelerated Growth‘. These treatments were designed to assess the mycelium’s responsiveness in terms of colour and texture development. A controlled set of samples was analysed using scanning electron microscopy, Fourier-transform infrared spectroscopy, and hydrophobicity testing to evaluate changes in microstructure, chemical composition, and surface properties. The results demonstrate that mycelium exhibits a measurable capacity for aesthetic adaptation, with distinct variations in pigmentation and texture emerging under different treatment conditions. These findings highlight the potential for co-creative design processes with living materials and offer new insights into the integration of biological responsiveness in design practices. The study contributes to the advancement of sustainable material systems and expands the possibilities for bio-design through controlled interaction with bio-materials.

Natural materials such as bone and enamel have intricate microstructures with inorganic minerals oriented to perform multiple mechanical and biological functions. Current additive manufacturing methods for biominerals from the calcium phosphate (CaP) family enable fabrication of custom-shaped bioactive scaffolds with controlled pore structures for patient-specific bone repair. Yet, these scaffolds do not feature intricate microstructures similar to those found in natural materials. In this work, we used direct material extrusion to 3D print water-based inks containing CaP microplatelets, and obtained microstructured scaffolds with various designs. To be shear-thinning and printable, the ink incorporated a concentration of 21 - 24 vol% CaP microplatelets of high aspect ratio. Good shape retention, print fidelity and overhanging layers were achieved by simultaneous printing and drying. Combined with the 3D design, versatile CaP microstructured objects can be built, from porous scaffolds to bulk parts. Extruded filaments featured a core-shell microstructure with graded microplatelet orientations, which was not affected by the printing parameters and the print design. A simple model is proposed to predict the core-shell microstructure according to the ink rheology. Given the remaining open porosity after calcination, microstructured scaffolds could be infiltrated with an organic phase in future to yield CaP biocomposites for hard tissue engineering.

Mycelium-bound composites (MBCs) grown from fungi onto solid lignocellulosic substrates offer a sustainable alternative to petroleum-based materials. However, their limited mechanical strength and durability are often insufficient for practical applications. In this work, we report a method for designing and developing strong and thermally insulating MBCs. The method grows mycelium onto 3D-printed stiff wood-Polylactic Acid (PLA) porous gyroid scaffolds, enhancing the strength of the scaffold while imparting other functional properties like thermal insulation, fire resistance, hydrophobicity, and durability. The extent of improvement in MBCs’ performance is directly dependent on the mycelium growth, and the best growth is observed at 90% porosity. We observe yield strength (σ y ) of 7.29 ± 0.65 MPa for 50% porosity MBC, and thermal conductivity (K t ) of 0.012 W/mK for 90% porosity MBC. Maximum improvement in σ y (50.4–77.7%) between before and after mycelium growth is observed at medium (70%)–high (90%) porosity. The MBCs also exhibit design-dependent improved fire-resistance and durability compared to the base wood-PLA scaffold, further enhancing their suitability for practical applications. Our findings show that integration of 3D printing, design, and biomaterials enables the development of sustainable bio-based composites to replace pollution-causing materials from the construction industry. Mycelium-bound composites grown from fungi onto solid lignocellulosic substrates show limited mechanical strength and durability for practical applications. Here, the authors report the growing of mycelium onto 3D-printed stiff wood-polylactic acid porous gyroid scaffolds as a method to produce strong and thermally insulating mycelium-bound composites.

Bioinspired self-shaping is an approach used to transform flat materials into unusual three-dimensional (3D) shapes by tailoring the internal architecture of the flat material. Bioinspiration and bioinspired materials have a high potential for fostering sustainable development, yet are often fashioned out of expensive and synthetic materials. In this work, we use bioinspiration to endow clay with self-shaping properties upon drying. The composites created are based on clay and starch, and the internal architecture is built using celery fibers. The viscosity, shrinkage, and bending of the architected composite monolayers are studied for several compositions by measuring penetration depth and using optical characterization methods. Bilayer structures inspired from plants are then processed using a simple hand layup process to achieve bending, twisting, and combinations of those after drying. By layering a mixture of 32 vol% clay, 25.8 vol% starch, and 42.2 vol% water with 40 wt% embedded aligned celery fibers, it is possible to obtain the desired shape change. The work presented here aims at providing a simple method for teaching the concept of bioinspiration, and for creating new materials using only clay and plant-based ingredients. Rejuvenating clay with endowed self-shaping properties could further expand its use. Furthermore, the materials, methods, and principles presented here are affordable, simple, largely applicable, and could be used for sustainable development in the domain of education as well as materials and structures.