Just a month ago I spent a week in Thailand at a nice resort where there was a water lily pond. The petals were closed as if they would need a few more days to bloom.
Actually, I was explained that those water lily flowers open up in all their glory during the night and at the first light of dawn they close their petals.
I woke up earlier one morning and took a walk with my camera to check the story, and it turns out it was true: the flowers were open and provided a wonderful sight.
I mention this because I saw a news coming from Harvard where scientists have decided to mimic Nature and create objects that can fold and take different shapes depending on their environment, just like it happens for water lilies and many other flowers and plants. They called this "biomimetic 4D printing".
The reason for the name is that the objects are created via 3D printing with a material that reacts to changes in the environment, like temperature or humidity (like the lilies) by changing their shape. The 4 refers to this capability of changing the shape over time and the "biomimetic" refers to the mimicking of Nature.
This can have application in several areas, like robotic skin, prosthetics, drugs delivery, tissue engineering, smart textiles. The possibility of creating objects using 3D printing provide the flexibility to design any shape and by using materials that can react to specific condition by shrinking or enlarging provides the tools for adaptation to the environment.
In order to do that trick the 3D printing has to be done in such a way that the changes in the material result in desired changes in the shape. This is were the 4D comes in. A software calculates the variations in the material and creates a 3D form that will morph in the desired one as environmental conditions change.
This software is the real innovation created by the researchers at Harvard.