By John Pavlus
Imagine playing a virtual-reality boxing game, complete with a menacing opponent aiming a haymaker at your head. You get your gloves up in time to block the punch, but you feel no impact when it hits, breaking the otherwise immersive experience.
Impacto, a prototype developed by researchers in the Human-Computer Interaction (HCI) lab at the Hasso Plattner Institute in Germany, sidesteps this deficit in mainstream VR experiences. The technology consists of an armband that combines basic haptic feedback (a tap or vibration on the skin) with electrical muscle stimulation to push or pull the user’s limb in a way that convincingly simulates a physical impact.
“It’s kind of an illusion,” says Patrick Baudisch, who leads the HCI lab. “We want the user wearing a VR headset to believe that he was really hit by something.”
Led by Pedro Lopes, the team simulated this physical force by re-creating the effect it would naturally have on the user’s body. They began with a VR boxing game using an Oculus Rift headset. To create the sensation of an opponent’s punch “landing,” the team developed a small armband that delivers a physical tap to the wearer’s skin at the point of virtual impact. A pair of electrodes stimulates the wearer’s biceps muscle to contract at the same time.