2D materials exposed to light could transform into 3D objects

A research team led by North Carolina State University (NC State) is developing methods to create 2D materials capable of folding themselves into 3D objects when exposed to light.

The work, funded by a grant worth approximately $1.76m (£1.11m) over four years from the US National Science Foundation (NSF), is inspired by origami and is claimed to have a broad range of potential applications.

‘We’re pulling together a diverse team of designers, engineers and mathematicians to advance our understanding of how to manipulate photoresponsive materials,’ said Dr Jan Genzer, Celanese professor of chemical and biomolecular engineering at NC State and the primary investigator under the NSF grant. ‘Ultimately, we hope to develop new techniques that have applications ranging from electronics to high-volume manufacturing to the delivery of humanitarian relief.’

According to a statement, the researchers plan to use experiments and computational models to evaluate the folding process in order to develop new multi-functional 3D structures that can form rapidly while retaining precise control over their shape.

Because the patterns will be on 2D materials, the process should be compatible with high-throughput patterning techniques, such as roll-to-roll patterning used in electronics manufacturing.

Potential applications include the development of unfoldable air foils that could be used for airdrops of humanitarian supplies with greater precision; the hands-free assembly of electronics in a ‘clean’ environment; or various packaging and manufacturing processes.

The research effort builds on earlier research from NC State, which detailed a simple way to convert 2D patterns into 3D objects using only light. In that work, the researcher ran pre-stressed plastic sheets through a conventional inkjet printer to print bold black lines on the material.

The material was then cut into a desired pattern and placed under an infrared light, such as a heat lamp. Because the bold black lines absorbed more energy than the rest of the material, the plastic contracted — creating a hinge that folded the sheets into 3D shapes.

A video demonstration of the previous work can be seen here.