CMU researchers create system enabling virtual kiss, sip of water

Is there a lovesick person among us who hasn’t imagined kissing someone they’re pining for? Or how about a thirsty individual imagining a cool sip of water?

While not necessarily a good substitute for the real thing, researchers at Carnegie Mellon University have figured out a way to exploit sensitivity in the lips, gums and tongue, second only to the fingertips in nerve density.

The researchers have developed a system that uses airborne ultrasound waves to create sensations on the lips, teeth and tongue. It is small and light enough to attach to the bottom of virtual reality goggles.

The result is that in a VR world that has a drinking fountain in it, “Every time you lean down and think you should be feeling water, all of a sudden you feel a stream of water across your lip,” said Vivian Shen, a second-year Ph.D. student in CMU’s Robotics Institute. “It makes the experience much more immersive.”

Alas, a virtual kiss feels nothing like a real kiss, and the water feels weird, according to Shen, because it’s not wet.

The same system is used to create haptic effects such as raindrops, mud splatter and crawling bugs. Haptic technology refers to any technology that can create an experience of touch by applying forces, vibrations or motions to the user.

But who wants mud splatter and crawling bugs? VR gamers do.

“We thought a lot about what the current market for VR is,” said Shen. “A lot of people are interested in VR horror games. With horror games, the more immersive it is, the more into that category of game you get.”

Working in the Future Interfaces Group, Shen and Craig Shultz, a post-doctoral fellow in the Human-Computer Interaction Institute, have used the system to create the effects.

At the end of the day, it’s about enhancing the entertainment experience, Shen said.

Among other things, the haptic effects are made up of persistent vibrations targeted on the mouth and synchronized with visual images. A variety of effects were evaluated using 16 volunteers and CMU reports that all the subjects said the mouth haptics enhanced their VR experience.

“Without haptics, it was difficult to tell when things were supposed to be touching my face,” one volunteer said.

However, not all effects are equal. The ones that are mouth-specific – such as brushing teeth, feeling raindrops from an open window or feeling a bug walk across your lips – were the most successful. Others, such as the feel of walking through cobwebs, were less powerful.

According to Shen, the sensations are limited primarily to the hands and mouth.

“You can’t really feel it elsewhere. Our forearms, our torso, those areas lack enough of the nerve mechanoreceptors you need to feel the sensation,” she said.

Shen did a presentation Monday at the Association for Computing Machinery’s Conference on Human Factors in Computing Systems in New Orleans. She won a Best Paper award.

“If we’re trying to create these virtual realities that mimic real reality, we will have to consider tactility and haptics as part of that,” she said. “It’s not just sound and visual. Our everyday life includes feeling things on our skin.”