When we think of mass production, the image is of a factory floor. Take a car. The engine block is cast, either from iron or aluminum. The hood, doors, and roof are stamped out on 100-ton presses. Gears are carved from metal blocks by milling machines or punched out by dies. The console and interior handles are injection-molded or carved, the mats and seats woven or stitched together. Some of these processes date to the Industrial Revolution, others to the Iron Age. The natural world doesn’t use any of them. One of its favorite methods is to take something flat and fold it into a three-dimensional form. Flowers, leaves, wings, proteins, mountain ranges, eyelids, ears, DNA—all are created by folding.
Today researchers in robotics, biology, math, and computer science are immersing themselves in that method. Scientists are looking at how materials and molecules wrinkle, drape, flex, and crease. They’re using folding to design everything from robots to cancer drugs, from airbags to mirrors for satellite telescopes. An Oxford University engineer named Zhong You has used origami to design better-crumpling car bumpers and flexible, low-cost stents. A team at Wake Forest University has used origami folding to create a fabric of densely layered nanotubes that can generate power from body heat. In a range of fields, fabrication by folding has the potential to be far faster, cheaper, and less energy-intensive than traditional methods and to work at very, very small scales, where even the most precise mills and lathes have all the accuracy of an earthquake. Makers of medical equipment and consumer electronics are looking at folding as a way to streamline manufacturing processes.
“We have a paradigm where we want to build things by having a solid block and then etching away at the block until you get whatever shape that you want,” says William Shih, a Harvard University biochemistry professor. Think of Michelangelo chiseling his forms from boulders of marble, or a milling machine carving an engine part out of a hunk of steel. “The way that nature does things is different,” Shih says. “It uses a folding algorithm, and it’s something that seems to be very efficient. We can look to nature for inspiration.” Shih himself has designed devices at the nanoscale that assemble themselves out of DNA strands, a process known as DNA origami.
Folding is, at heart, a geometry problem, and the groundwork for much of the new research is being laid by mathematicians. The increasingly ingenious applications, though, are driven by collaborations between engineers, scientists, and programmers: “Biologically inspired engineering” is an ambitious new way of doing science that treats living organisms like mechanical systems. Just as the diameter of a gear or the strength of a spring determines how a clock works, the shape and tensile qualities of folded proteins determine their roles in the countless processes that keep the human body running. Deciphering those relationships and building off of them are part of what the new science of folding is about.
by Drake Bennett, Bloomberg Businessweek | Read more:
Photograph by Leonard Greco