As conference participants steered their character in a shoot-em-up computer video game based on Half-Life 2, the vest variously smacked them and vibrated as they themselves got shot. Sometimes it smarted, depending on how tight the vest was on the user, or if the “shots” hit right on the collar bone. For me it was more like a series of surprise punches.
Four solenoid actuators in the chest and shoulders in front, plus two solenoids in the back, give you the feeling of a gunshot, says Saurabh Palan, a graduate student who works on the project. In addition, vibrating eccentric-mass motors clustered against the shoulder blades make you feel a slashing effect as you get stabbed from behind. Currently there is no feedback from your own weapons as you fire, just from weapons aimed at you.
Something similar to this vest was launched in 2007 by TN Games.