Researchers have developed a technique that programs 2D materials to transform into complex 3D shapes. Programming thin sheets, or 2D materials, to morph into 3D shapes can enable new technologies for soft robotics, deployable systems, and biomimetic manufacturing, which produces synthetic products that mimic biological processes. The 2D material programming technique allows the team to print 2D materials encoded with spatially controlled in-plane growth or contraction that can transform to programmed 3D structures.
There are a variety of 3D-shaped 2D materials in biological systems that play diverse roles. Biological organisms often achieve complex 3D morphologies and motions of soft, slender tissues by spatially controlling their expansion and contraction. Such biological processes inspired the team to develop a method that programs 2D materials with spatially controlled in-plane growth to produce 3D shapes and motions.
The researchers developed an approach that can uniquely create 3D structures with doubly curved morphologies and motions commonly seen in living organisms but that are difficult to replicate with manmade materials. They were able to form 3D structures shaped like cars, stingrays, and human faces. To physically realize the concept of 2D material programming, they used a digital light 4D printing method they developed.
The 2D printing process can simultaneously print multiple 2D materials encoded with individually customized designs and transform them on demand and in parallel to programmed 3D structures. The approach is scalable, customizable, and deployable and can potentially complement existing 3D-printing methods.
The team also introduced the concept of cone flattening, where they program 2D materials using a cone surface to increase the accessible space of 3D shapes. To solve a shape selection problem, they devised shape-guiding modules in 2D material programming that steer the direction of shape morphing toward targeted 3D shapes. Their flexible 2D-printing process can also enable multi-material 3D structures.