None of those nice, warm wool sweaters you see at the department store were knitted by hand — that would be prohibitively expensive. Instead, they were created on industrial knitting machines that can be programmed to weave all sorts of patterns. In order for e-textiles, and their corresponding sensors, to be commercially-viable, they’ll need to take advantage of those same machines. That’s why a team of researchers from MIT have developed SensorKnits, which are machine-friendly e-textile sensors.
SensorKnits was created by researchers in the Tangible Media Group, within the MIT Media Lab. The underlying technology was developed specifically for use with the automated knitting machines that are already commonplace today, which would make wearable e-textiles that utilize it practical and affordable. The key to the technology is the considered use of conductive yarn in combination with dielectric yarn.
Both of those yarn types are already commercially-available, and the dielectric yarn acts as an electrical insulator. By weaving the two types of yarn in specific patterns, the researchers are able to create e-textiles that have unique resistive, piezoresistive, and capacitive properties. Those properties can, in turn, be measured with traditional sensors.
To demonstrate the capabilities of SensorKnits, the researchers built it into three prototypes. The first is a tablecloth with adjustable sliders that control the room’s lighting color. The second is a light-up belt intended for cyclists and pedestrians. The third is a musical handbag that can be played like a keyboard. None of those is destined for the commercial market, but the SensorKnits technology very well could be.