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Natural systems are a rich source of scientific inspiration. Skin for example functions as an efficient protective barrier for the human body that is able to sense the external environment and repair autonomously. The translation of these physiological properties to synthetic materials could open new opportunities in many strategic fields from health care to robotics. In recent years, significant advances have been accomplished towards the development of synthetic materials with unique sensing and/or self-healing capabilities [1,2] . The ability to self-heal often relies on the use of an external stimulus to trigger repair [3] or on the use of vascular [1,4] or capsule-based [5] systems for the storage and release of healants upon damage. However, these systems often show incomplete healing, cannot heal multiple times, or require the prompt location of the damage site. An alternative is the use of supramolecular polymers (macromolecular aggregates cross-linked by dynamic covalent or hydrogen bonds) that provide an efficient path towards autonomous multiple self-healing [6] . Still, the integration of healing ability with functional capabilities in robust and lightweight materials remains a challenge. In this work, we marry both approaches to develop robust, electrically conductive, self-healing composites. These composites, prepared through the encapsulation of a self-healing supramolecular polymer in a graphene ultralight network, are able to sense pressure and flexion and completely and

Direct Ink Writing (DIW) potential in developing multi-material structures.

The current lifestyles, increasing population, and limited resources result in energy research being at the forefront of worldwide grand challenges, increasing the demand for sustainable and more efficient energy devices. In this context, additive manufacturing brings the possibility of making electrodes and electrical energy storage devices in any desired three-dimensional (3D) shape and dimensions, while preserving the multifunctional properties of the active materials in terms of surface area and conductivity. This paves the way to optimized and more efficient designs for energy devices. Here, we describe how three-dimensional (3D) printing will allow the fabrication of bespoke devices, with complex geometries, tailored to fit specific requirements and applications, by designing water-based thermoresponsive inks to 3D-print different materials in one step, for example, printing the active material precursor (reduced chemically modified graphene (rCMG)) and the current collector (copper) for supercapacitors or anodes for lithium-ion batteries. The formulation of thermoresponsive inks using Pluronic F127 provides an aqueous-based, robust, flexible, and easily upscalable approach. The devices are designed to provide low resistance interface, enhanced electrical properties, mechanical performance, packing of rCMG, and low active material density while facilitating the postprocessing of the multicomponent 3D-printed structures. The electrode materials are selected to match postprocessing conditions. The reduction of the active material (rCMG) and sintering of the current collector (Cu) take place simultaneously. The electrochemical performance of the rCMG-based self-standing binder-free electrode and the two materials coupled rCMG/Cu printed electrode prove the potential of multimaterial printing in energy applications.

The directional freezing of micro-fiber suspensions is used to assemble highly porous (porosities ranging between 92 to 98%) SiC networks. These networks exhibit a unique hierarchical architecture in which thin layers with honeycomb-like structure and internal strut length in the order of 1 to 10 µm in size are aligned with an interlayer spacing ranging between 15 to 50 microns. The resulting structures exhibit strengths (up to 3 MPa) and stiffness (up to 0.3 GPa) that are higher than aerogels of similar density and comparable to other ceramic micro-lattices fabricated by vapor deposition. Furthermore, this wet processing technique allows the fabrication of large-size samples that are stable at high temperature, with acoustic impedance that can be manipulated over one order of magnitude (0.03-0.3 MRayl), electrically conductive and with very low thermal conductivity. The approach could be extended to other ceramic materials and opens new opportunities for the fabrication of ultralight structures with unique mechanical and functional properties in practical dimensions.2

The properties of graphene open new opportunities for the fabrication of composites exhibiting unique structural and functional capabilities. However, to achieve this goal we should build materials with carefully designed architectures. Here, we describe the fabrication of ceramic-graphene composites by combining graphene foams with pre-ceramic polymers and spark plasma sintering. The result is a material containing an interconnected, microscopic network of very thin (20–30 nm), electrically conductive, carbon interfaces. This network generates electrical conductivities up to two orders of magnitude higher than those of other ceramics with similar graphene or carbon nanotube contents and can be used to monitor ‘in situ' structural integrity. In addition, it directs crack propagation, promoting stable crack growth and increasing the fracture resistance by an order of magnitude. These results demonstrate that the rational integration of nanomaterials could be a fruitful path towards building composites combining unique mechanical and functional performances.

Ultralight and strong three-dimensional (3D) silicon carbide (SiC) structures have been generated by the carbothermal reduction of SiO with a graphene foam (GF). The resulting SiC foams have an average height of 2 mm and density ranging between 9 and 17 mg cm(-3). They are the lightest reported SiC structures. They consist of hollow struts made from ultrathin SiC flakes and long 1D SiC nanowires growing from the trusses, edges, and defect sites between layers. AFM results revealed an average flake thickness of 2-3 nm and lateral size of 2 μm. In-situ compression tests in the scanning electron microscope (SEM) show that, compared with most of the existing lightweight foams, the present 3D SiC exhibited superior compression strengths and significant recovery after compression strains of about 70%.

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