Virtual Reality

VR Device Replicates Touch

• By Dian Schaffhauser
• 04/30/20

A new virtual reality device from a team of Carnegie Mellon University researchers allows users to feel walls and solid objects. The invention, dubbed "Wireality," uses multiple string-loaded cables attached to the hand and fingers to simulate the sensation of solidity. When a user's hand is close to a wall in the virtual environment, for example, the strings are locked in place to emulate the sensation of touching the wall. Similar actions enable the user to feel the surface of an irregular object, sense resistance when he or she pushes up against something or interact physically with a virtual character.

The haptic device uses modular, spring-loaded cables controlled by a shoulder-mounted device running on batteries. The lead researcher on the project was Cathy Fang, who will graduate from the university with a dual degree in mechanical engineering and human-computer interaction.

"I think the experience creates surprises, such as when you interact with a railing and can wrap your fingers around it," Fang said, in a statement. "It's also fun to explore the feel of irregular objects, such as a statue."

According to a paper published by the Conference on Human Factors in Computing Systems (CHI 2020) and placed in the Association for Computing Machinery's digital library, user evaluation of the multistring device declared it more realistic than other haptic techniques. While other research projects have used strings to create haptic feedback in virtual worlds, they have typically used motors to control the strings. The CMU researchers envisioned a system light enough to be worn by the user and affordable for consumers.

"The downside to motors is they consume a lot of power," said Fang. "They also are heavy."

As a motor substitute, Wireality uses spring-loaded retractors, such as those found on key chains or ID badges. A ratchet mechanism can be rapidly locked through electronic controls. The springs themselves, not motors, tighten the strings, requiring just a small amount of electrical power, provided by the batteries.

A Leap Motion (now UltraLeap) sensor, attached to the VR headset, tracks hand and finger motions. When the sensor senses that a user's hand is in proximity to a virtual wall or other object, the ratchets engage in a sequence relevant to the interaction. When the user withdraws his or her hand, the latches disengage.

Wireality weighs about 10 ounces and would cost about $50 to produce in large quantities, making it suitable, according to Fang, for VR games and other experiences involve interaction with the physical world.

The research team has made a video that explains the device and how it works available on YouTube.