Jennifer Lewis from the University of Illinois and her team have developed a novel way to ‘print’ complex three-dimensional shapes. They used flat sheets of titanium hydride ink, and folded them.
Solid objects can be ‘printed’ by laying out each layer of ink in precise sequence. The inks contain metal, plastic or ceramic particles. When the desired shape is reached, the liquid ink is evaporated, leaving the particles annealed into a solid structure. Unfortunately, if too many layers are added, the entire structure can start to sag or even collapse. Lewis and her colleagues decided to start with a flat sheet of ink and fold it into the desired shape.
These structures were folded from flat sheets of direct-printed titanium hydride ink, a new technique pioneered by University of Illinois researchers.
Credit: Bok Yoep Ahn (a postdoctoral researcher in the Lewis lab).
This required some fiddling to get the right ink consistency. Some ink solvents dry too quickly, making the sheets too brittle for consecutive folds. Other solvents don’t dry quickly enough, allowing the structures to fall apart. A happy medium left the sheets pliable enough to fold, but stiff enough to hold their shape throughout the folding and annealing process.
The ability to make tiny precise objects would have many uses, particularly in medicine and electronics.To see a slideshow of some of the printed origami creations, look here.