Researchers have created a 3D printer-compatible hydrogel that is mechanically tough and able to repeatedly change shape in response to water temperature. The scientists have demonstrated the technology by 3D-printing an autonomous water valve, …. but the material could also be used to create soft robots, custom designed sensors and self-assembling macrostructures.
The aim of so-called “4D printing” is to extend additive manufacturing to the dimension of time. The idea is to create 3D-printed objects using special materials that are sensitive to heat, water or pressure that can autonomously change shape in very specific, purposeful ways in response to environmental conditions, long after they’ve come out of the printer. In some cases, the objects can even revert back to their original shape.
Examples of 4D printing have included simple self-assembling bodies that fold together when baked, polymers that bend into shape in response to water, heat or pressure, and smart strands inspired by self-assembling nanostructures. Admittedly, 4D printing is far from practical in its current iteration, but the technology is very young and will likely take big steps forward as 3D printing becomes more accessible. … (read more)