We've already heard about touch-sensitive clothing, which allows devices to be controlled by touching and swiping fabric with touch-screen-like fingers. This technology sounds impressive, but it does have some limitations. That's where a new "touchless" finger gesture detection fabric comes in. The experimental fabric was developed by scientists from Nottingham Trent University in the UK, the Helmholtz Zentrum Research Laboratory in Dresden-Rosendorf, Germany, and the Free University of Bozen-Bolzano in Italy.
The general idea is that if this technology were integrated into clothing, the wearer would be able to perform tasks such as turning on an appliance, answering a phone call, or operating a smart TV simply by moving their index finger through the air space above the material.
In the current prototype version of the system, the user wears a ring with a 3x5 mm magnet on their index finger.
The magnetic field emitted by the ring affects the resistance of four magnetoresistive sensors woven into a polyester sleeve. By comparing the extent to which the magnetic field simultaneously affects the resistance of each sensor, a connected microprocessor determines the real-time three-dimensional position of the finger in the space above the sleeve.
Different finger positions/actions are assigned to different instructions, which are forwarded to wirelessly connected electronic devices. In the prototype system, the wearer can turn sideways or move forward in the VR environment with simple finger gestures.
Each sensor consists of a small piece of polyimide foil covered with layers of copper and cobalt. The sheet is wrapped around a thin wire and then encased in a polyester sheath, creating an individually braided wire that is woven into the fabric. In lab tests, the sensor continued to function even after seven washing machine washes.
In contrast, capacitive textile sensors, which must actually be touched, tend to be much more fragile and often less flexible, making enhanced "smart" garments more uncomfortable to wear. They can also be triggered accidentally as they rub against the user's skin as they move around.
Finally, capacitive touch sensors don't work underwater or in other wet environments (like in the rain or when you're sweating), a problem that doesn't exist with newer contactless sensors.
Lead scientist Dr Pasindu Lugoda of Nottingham Trent University said: "Our design could revolutionize e-textiles for both specialized and everyday clothing. "It is machine washable, durable and does not affect the drape or overall aesthetics of the fabric. "
A paper on the research was recently published in the journal Communications Engineering.