4D-printed robot self-assembles into a tube and rolls up hills

A tube shaped 4D-printed robot can roll uphill, carry a load, and navigate an unpredictable landscape. Wei Feng at Tianjin University in China and his colleagues designed the robot, which is built from a flat rectangular sheet of 3D-printed liquid crystal elastomer. When the surface this sheet is placed on is heated above 160 C, the sheet self assembles by rolling into a tubular form, taking on the appearance of a piece of hollow, spiralled spaghetti. This change in shape over time adds a fourth dimension to the construction process, making this what the researchers call a 4D-printed robot.