A new assembly method based on an ancient Japanese paper art instantly transforms 2D structures into complex 3D shapes. The results, reported by a Northwestern University and University of Illinois research team, could be useful in tissue engineering and microelectromechanical systems.
The builders borrowed ideas from Kirigami, the ancient Japanese technique for forming paper structures by folding and cutting.
Starting with 2D structures formed using state-of-the-art methods in semiconductor manufacturing and carefully placed “Kirigami cuts,” the researchers created more than 50 different mostly closed 3D structures that, in theory, could contain cells or support advanced electronic or optoelectronic devices. Such capabilities position the technique for potential use in tissue engineering and industrial applications, including biomedical devices, energy storage, and microelectromechanical systems.
The research team made 3D structures from materials including silicon, polymers, metals, and dielectrics. Some structures combined a number of materials, such as gold and a semiconductor, including patterns that provide useful optical responses.
The engineers used a flat material adhered at certain places to a stretched substrate. Cuts were strategically made; when the stretch was released and the surface “popped up” into three-dimensions, all the physical strain from the new 3D shape were released through the cuts, keeping the structure from breaking.
Sizes of the 3D structures range from 100 nanometers square to 3 centimeters square while the cuts themselves are tiny: typically between 1 micron and 10 microns wide for silicon 3-D structures — small enough to interface directly with cells or intracellular structures or to manipulate components in microelectronics.