Northwestern University researchers have developed a new thin, wireless system that adds a sense of touch to any virtual reality (VR) experience. Not only does this platform potentially add new dimensions to our long-distance relationships and entertainment, the technology also provides prosthetics with sensory feedback and imparts telemedicine with a human touch.
Referred to as an “epidermal VR” system, the device communicates touch through a fast, programmable array of miniature vibrating actuators embedded into a thin, soft, flexible material. The 15-centimeter-by-15-centimeter sheet-like prototypes comfortably laminate onto the curved surfaces of the skin without bulky batteries and cumbersome wires, reports Amanda Morris in Northwestern University.
“People have contemplated this overall concept in the past, but without a clear basis for a realistic technology with the right set of characteristics or the proper form of scalability. Past designs involve manual assemblies of actuators, wires, batteries and combined internal and external control hardware,” said Northwestern’s John A. Rogers, a bioelectronics pioneer. “We leveraged our knowledge in stretchable electronics and wireless power transfer to put together a superior collection of components, including miniaturized actuators, in an advanced architecture designed as a skin-interfaced wearable device — with almost no encumbrances on the user. We feel that it’s a good starting point that will scale naturally to full-body systems and hundreds or thousands of discrete, programmable actuators.”
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“We are expanding the boundaries and capabilities of virtual and augmented reality,” said Northwestern’s Yonggang Huang, who co-led the research with Rogers. “By comparison to the eyes and the ears, the skin is a relatively underexplored sensory interface that could significantly enhance experiences.”
The research will be published on Nov. 21 in the journal Nature.
How it works
The patch wirelessly connects to a touchscreen interface (on a smartphone or tablet). When a user touches the touchscreen, that pattern of touch transmits to the patch. If the user draws an “X” pattern on the touchscreen, for example, the devices produce a sensory pattern, simultaneously and in real-time, in the shape of an “X” through the vibratory interface to the skin.
When video chatting from different locations, friends and family members can reach out and virtually touch each other — with negligible time delay and with pressures and patterns that can be controlled through the touchscreen interface.
“You could imagine that sensing virtual touch while on a video call with your family may become ubiquitous in the foreseeable future,” Huang said.
The actuators are embedded into an intrinsically soft and slightly tacky silicone polymer that adheres to the skin without tape or straps. Wireless and battery-free, the device communicates through near-field communication (NFC) protocols, the same technology used in smart phones for electronic payments.
“With this wireless power delivery scheme, we completely avoid the need for batteries, with their weight, size, bulk and limited operating lifetimes,” Rogers said. “The result is a thin, lightweight system that can be worn and used without constraint, indefinitely.”
‘A starting point’
Rogers views the current device as a starting point. “This is our first attempt at a system of this type,” he said. “It could be very powerful for social interactions, clinical medicine and applications that we cannot conceive of today, beyond the obvious opportunities in gaming and entertainment.”
He and Huang are already working to make the current device slimmer and lighter. They also plan to exploit different types of actuators, including those that can produce heating and stretching sensations. With thermal inputs, for example, a person might be able to sense how hot a cup of coffee is through prosthetic fingertips.
The Northwestern team believes the overall engineering framework can accommodate hundreds of actuators with dimensions significantly smaller than those used currently, which have diameters of 18 millimeters and thicknesses of 2.5 millimeters.
Eventually, the devices could be thin and flexible enough to be woven into clothes. People with prosthetics could wear VR shirts that communicate touch through their fingertips. And along with VR headsets, gamers could wear full VR suits to become fully immersed into fantastical landscapes.
“Virtual reality is a very important emerging area of technology,” Rogers said. “Currently, we’re just using our eyes and our ears as the basis for those experiences. The community has been comparatively slow to exploit the body’s largest organ: the skin. Our sense of touch provides the most profound, deepest, emotional connection between people.”
