Researchers from the City University of Hong Kong (CityU) have successfully developed the world’s first-ever 4D printing for ceramics that can be used to create complex, shape-changing objects.
1. The researchers made use of the elastic energy stored in the stretched precursors for shape morphing. When the stretched ceramic precursors are released, they undergo self-reshaping.
2. The resultant elastomer-derived ceramics are mechanically robust. They can have a high compressive strength-to-density ratio, and they can come in large sizes with high strength compared to other printed ceramics.
3. After heat treatment, the precursors turn into ceramics. Ceramic has a high melting point, so it is difficult to use conventional laser printing to make ceramics.
4. The existing 3D-printed ceramic precursors, which are usually difficult to deform, also hinder the production of ceramics with complex shapes.
5. To overcome these challenges, researchers developed a novel ‘ceramic ink’, which is a mixture of polymers and ceramic nanoparticles.
The research team was led by Professor Jian Lu, Vice-President (Research and Technology) and Chair Professor of Mechanical Engineering, who is a distinguished materials scientist with research interests ranging from fabricating nanomaterials and advanced structural materials to the computational simulation of surface engineering. It took the team more than two and a half years to overcome the limitations of the existing materials and to develop the whole 4D ceramic printing system.