The challenge for the researchers was to use a stable ceramic emulsion that did not collapse during or after printing. The resulting structure is similar to those found in nature, such as the form of bones, writes the Federal Institute of Technology (ETH) in a statement.
Doctoral student Carla Minas used an emulsion consisting of an aqueous solution, ceramic particles and other substances. The emulsion contains oil droplets, on whose surface the ceramic particles are placed. This stabilises the droplets, preventing them from fusing with neighbouring droplets. The particle size determines the subsequent pore volume. After the material is printed, the structure is dried, causing the oil to evaporate. The result is a ceramic component that is 95 per cent pores yet extremely robust. The component features all the properties essential for lightweight construction materials. Its high porosity at different length scales also makes it well suited to other applications including in the chemicals industry, biomedicine or energy sector.
Researchers at the IBM Research Center in Rüschlikon in the canton of Zurich are currently carrying out research into residual heat, which requires materials that can absorb water efficiently and release heat in the process. The ETH development is especially well suited to such an application as the components can be printed in whatever shape required thanks to the 3D printing process.