Background

Shape-programmable materials can transform into different shapes and therefore achieve mechanical functionalities unattainable by traditional machines. Their shape transformation can be controlled by heat, light, chemicals, pressure or magnetic field. Unfortunately, shape-programmable materials with an overall dimension of <1 cm can either transform into only one or two forms, or their transformation requires several minutes, which is insufficient to mimic complex biological systems. Therefore, an approach to create and to program miniaturized devices made of shape-programmable materials is highly demanded.