New Knitting Technology Produces 3D Force Sensors in Fabric

Wearable technology precludes the use of many conventional hardware components, as user comfort becomes the highest priority. Even the earliest of adopters have little interest in strapping hard, bulky devices to their bodies. A rigid LCD panel is perfectly acceptable when it goes in a stationary TV, but becomes far less desirable when someone has to wear it. Sensors and human interface devices (HIDs) need to become more like clothing to gain appeal in the wearables industry, which is where the SpaceR 3D force sensor knitting technology comes in.

Buckles and buttons aside, most of what humans wear is soft and flexible. That makes sense, since clothing needs to conform to our bodies as we move through the world. Your pants would be awfully uncomfortable if they were made of sheets of stainless steel — just ask a knight from the Middle Ages. SpaceR is automated knitting technology that can produce 3D force sensors that blend comfortably into the textile clothing that people already wear.

Resistive touch sensors, including the digitizers used for touchscreens, work by measuring the resistance between two points separated by gap. As the points get closer or further, like when someone pushes on the sensor and then releases it, the resistance changes in a measurable way. Resistive touchscreen digitizers contain two matrices separated by a gap, so they can detect the coordinates at which the resistance changes. SpaceR technology works in the same way, but uses conductive, non-conductive, and resistive thread woven into 3D structures.

The simplest SpaceR sensor resembles a lump of fabric and retains its natural shape thanks to an internal woven lattice. It can detect both a press and the amount of pressure (roughly equivalent to force). The output is analog, so it provides an infinite spectrum between on and off. That alone gives a single SpaceR sensor more capability as an interface element than a conventional button. But SpaceR also works in more complex arrangements.

SpaceR’s developers, Roland Aigner, Mira Alida Haberfellner, and Michael Haller, demonstrated complex control with a few different implementations. The first is a four-way directional pad useful for navigation. It works like the basic sensor, but divided into zones to determine which area receives more pressure than the others. The last demonstration was experimental and more interesting. It looks like a textile tube and contains SpaceR sensors to detect squeezing forces. A virtual cylinder deforms proportionally to the force that the user exerts on the physical device. They didn’t have a practical purpose in mind for that, but it does bring up interesting possibilities.

SpaceR technology has obvious appeal in the wearables industry, as it easily integrates into traditional textile clothing. SpaceR sensors could go on shirts, scarves, gloves, and just about anything else, providing an interface for interacting with a wearable device.