Today's virtual reality games and content can be pretty immersive, but they largely miss the mark when it comes to haptic feedback. Wouldn't it be cool to 'feel' a textured object, or perceive the sensation of running your hand over rich fabric in VR?
That's what researchers at Northwestern University in Evanston, Illinois, are hoping to achieve with their new wearable. It's a lightweight device about the size of your fingertip that can go far beyond simply vibrating against your skin to deliver richer haptics using more sophisticated tech.
"Almost all haptic actuators really just poke at the skin," said John A. Rogers, a Professor of Materials Science and Engineering at the university who led the device design. "But skin is receptive to much more sophisticated senses of touch. We built a tiny actuator that can push the skin in any direction and in any combination of directions. With it, we can finely control the complex sensation of touch in a fully programmable way."
Unlike vibrating motors that simply buzz in different patterns, this tech addresses how the sense of touch is realized through several different kinds of mechanoreceptors – which you can think of as sensors – within the skin. They reside at varying depths, and have different levels of sensitivity.
By combining a newly developed actuator with full freedom of motion, Bluetooth connectivity, an accelerometer, and a tiny battery, this little gizmo can wirelessly simulate a range of sensations, including vibrations, stretching, pressure, sliding and twisting. It can also combine sensations and operate at different speeds.
That actuator can move in any direction along the skin, to engage many mechanoreceptors at once, and it can be arranged in arrays to produce a wider range of tactile sensations.
It sounds like a simple contraption, and maybe that's what makes it pretty cool. A tiny magnet is attached to wire coils that are connected to a battery. When electricity flows through the coils, a magnetic field is generated, and that moves, pushes, pulls, or twists the magnet. When combined in an array, these actuators can reproduce different sensations.
Depending on where the haptic is mounted – say, on the back of your hand or on a fingertip – the onboard accelerometer delivers information to the system about whether you're moving quickly or slowly, and in which direction. That can make for more realistic motion tracking.
That should help the sensory feedback component of VR experiences catch up to the realistic, high-fidelity audio and video we've come to expect when donning a headset.
Beyond enabling more immersive experiences, Rogers notes they can also assist with other novel applications. "If you run your finger along a piece a silk, it will have less friction and slide faster than when touching corduroy or burlap," he said. "You can imagine shopping for clothes or fabrics online and wanting to feel the texture."
In another example, the system helped convert the sound of music into physical touch, so a user could differentiate between tones and instruments by the direction of vibrations they were feeling from the wearable.
This tech could also help people with visual impairments experience immersive forms of media, and navigate their surroundings. The team's paper on this device will appear in the journal Science on March 28.
Source: Northwestern University
