The research group from the City University of Hong Kong (China) developed the world's first technology of four-dimensional printing of ceramics, which can take complex forms after printing.
Ceramics have a high melting point, so it is difficult to use conventional laser printing to produce it. Three-dimensional ceramic blanks are almost impossible to deform, which also hinders the production of complex ceramics. To overcome these problems, a team of Chinese scientists developed polymer-oxide precursors or "ceramic ink", which is a mixture of polymers and ceramic nanoparticles. 3D-printed ceramic parts created from these inks are soft and can stretch. Of these flexible blanks, you can create complex shapes that are composed according to the origami principle.
The technology of 4D-printing is a usual three-dimensional printing in combination with an additional element of time: printed objects can change their shape or fold themselves into necessary shapes after printing under the influence of an external influence - temperature or magnetic field. In the new study, engineers used energy, which appears in the printed substrate due to tension. Stretched ceramic blanks spontaneously add to the desired shape, and after heat treatment turns them into a solid ceramic.