VR system uses electric 'shocks' to create haptic feedback

VR with walls Hasso-Plattner-Institut

A team of scientists at the Hasso Plattner Institute in Germany has created a VR system that uses electrical 'shocks' to simulate walls and heavy objects.

The idea is to prevent the user’s hands from penetrating virtual objects by means of electrical muscle stimulation (EMS). As the user lifts a virtual cube, the system lets the user feel the weight and resistance of the cube. The heavier the cube and the harder the user presses the cube, the stronger a counterforce the system generates.

"We were really interested in trying to explore one of the hardest things to recreate in terms of physical sensation, which is a wall," says co-author Pedro Lopes.

The medical-grade eight-channel EMS is worn in a backpack, which is controlled over USB by a VR simulator that works with Samsung GearVR, hand-mounted trackers and a motion capture system.

"The major potential here is that this is something you can have with very little hardware," Lopes explains.

The team attached electrodes to users' forearms and biceps, which automatically apply a mild electrical shock when they touch or lift a virtual object. That tenses the activated muscle, repulsing the users hand and making them feel they're pushing against a wall or picking up a heavy cube.

When the user grabs the virtual cube, the user expects the cube’s weight to create tension in the user’s biceps and the cube’s stiffness to create a tension in the user’s pectoralis. In order to create this sensation, the system actuates the respective opposition muscles. In order to put a load onto the user’s biceps, it actuates the triceps and in order to put a load onto the user’s pectoralis, it actuates the user’s shoulder muscle. This creates the desired tension in biceps and pectoralis, thereby creating the desired experience.