The image above shows a magnification of a 1 mm-wide self-folded object, imaged with confocal microscopy. It is an origami design of a 3D octahedron-tetrahedron truss, independently discovered by many origamists. The sample shown is made of a soft polymer gel layer that swells when placed in water bonded to stiff plastic layers. As the soft layer swells, it builds up stresses that cause the sheet to bend to defined angles at locations specified by patterning the stiff layers. This allows the sheet to fold itself simply by placing it in water. UMass Amherst polymer scientists Ryan Hayward and Junhee Na and their colleagues are exploring the development of meta-materials from these tiny self-folding polymer sheets. The aim is to develop materials with precisely tunable and adaptable shapes and mechanical properties, including for possible applications in bio-medicine and soft robotics. Learn more.
Image credit: Junhee Na, Thomas Hull, and Ryan Hayward
Courtesy of the VISUAL Image Library