After a few decades of electronics developing at a dizzying pace–from personal computers and flip phones to wearable devices, smartphones and tablets–there are signs technological breakthroughs are stalling. For instance, your new iPhone really isn’t that much different from the previous one. And laptop computers pretty much all look–and work–alike.
Engineers need new inspirations for innovations. One source, believe it or not, is ancient arts. My work, for example, is inspired by the kirigami, a lesser-known cousin of the folding art of origami. You may even have done kirigami as a child, folding and cutting to make paper snowflakes. Materials inspired by these arts can be used to improve smart clothing, build bendable smartphones and make prosthetics lighter.
The word kirigami is the English name for the art of paper cutting. Archeologists say kirigami can be traced back before the 17th century in Japan. It is still a popular folk art in Asian countries, where people make kirigami to celebrate the lunar new year, newborn babies, marriage, and other significant events.
Typically, kirigami starts with a folded paper base, which is cut, unfolded, and flattened to make the final art piece. The intricate patterns create beautiful works of art based on math and design principles that can change the mechanical behaviors of the material being cut. For example, a particular pattern can make the paper stronger or more stretchable.
An engineering idea
Just as kirigami practitioners cut and fold paper, engineers can cut and fold materials that in turn can be incorporated into electronic devices.
The research community, as well as tech and apparel companies, is eager to make electronic devices as flexible and bendable as possible. The trick is to make sure the flexibility of these gadgets does not limit their ability to handle electricity.
Turning to electronics
Recently, my research group at the University at Buffalo fabricated a novel kirigami-inspired stretchable electronic device. Made of self-assembled polymers and nanowires, the device is a centimeter wide. On its own it could stretch slightly–to just 1.06 centimeters. But when cut with lasers in a pattern inspired by kirigami, the same device can stretch up to 20 centimeters, 2,000% larger than its unstretched form. The material’s innate elasticity helps, but the pattern and orientation of the cuts is the major factor in how the device deforms.
Moreover, the cutting made the device 3,000 times more conductive of electricity, meaning the electronics can run faster, or take less time to charge.
Stretchable electronics are also key to Samsung’s plans to release a bendable smartphone. And they could be central to smart clothing, an industry that analysts project could be worth US$4 billion by 2024. Thanks to artistic innovations hundreds of years ago, clothes and bandages may one day be able to help athletes maximize performance, monitor the health of people with chronic illnesses, and give soldiers and emergency workers important information about themselves and those in their care.
Shenqiang Ren is a professor of mechanical engineering at the University at Buffalo at the State University of New York.