Kirigami-inspired folds and cuts enables flexible, stretchable circuits

If we ever hope to wear truly smart clothing, we’ll need to really work on how fabrics are made. It’s not that there’s anything wrong with cotton or wool, but a smart, as in computerized, jacket or shirt will need to somehow incorporate electric circuits and sensors in a way that won’t inhibit movement. Since current wiring can generally only flex by six percent before inhibiting electrical currents and efficiency, engineers are looking into techniques pioneered by Japanese papercraft known as kirigami to boost the flexibility of otherwise stiff substances.

Structures and circuits

Kirigami is a method of sculpting with both careful folds and strategic slices in each sheet of paper. While origami can create amazing shapes with just folds, making small slices in the paper can often simplify what folds are needed to achieve a similar shape. Those properties make it attractive for making 3D structures out of materials normally printed or shipped as flat sheets, almost like a pop-up book.

For electronics designers, the interest in kirigami is focused more on how cuts and folds can add flexibility to a material without losing tensile strength. Making wiring in a kirigami-inspired lattice shape allows polymers like PthTFB to be stretched and bent by 2,000 percent, without sacrificing any performance in the circuit.

A fit for electrified fabrics

Since these folds and slices are still beneficial on small scales, there are a lot of possible applications for flexible, stretchy circuits. Sensors in artificial skin could connect to nerves, displays could be build onto soft surfaces, or we could all start dressing ourselves in wearable computers. While not as inspiring as artificial skin for humans or robots, the smart clothing market is expected to be huge once these technologies mature, which is why kirigami isn’t the only kind of flexible circuit being developed these days. If you’re not into powering your shirt with papercraft, carbon-based spider silk may be the “it” textile you’ll be looking for next season.

Source: Ancient paper art, kirigami, poised to improve smart clothing, Science Daily