The idea behind 4D printing is that you take multi-material 3D printing -- so you can deposit multiple materials -- and you add a new capability, which is transformation, that right off the bed, the parts can transform from one shape to another shape directly on their own.
4D打印指的是 我们利用多材料进行三維打印 － 就是我们可以使用多种材料 － 同时我们又新加一种能力， 就是变形。 一但从车床上下来， 这些不同的零部件就可以直接自发的变成其他的形状，