According to a IEEE report, the system developed by a research team from the University of Chicago works by manipulating the nerves on the back of the hand to generate tactile sensations across the fingers and palm.
The haptic system relies on a bodily phenomenon known as “referred sensation,” which is when a stimulation in one part of the body leads to sensation in another part. An example of this is the sensation of tingling felt in the fingers when you bang your elbow.
According to the researchers, referred sensation in the fingers can be induced with a reasonable amount of accuracy.
According to the IEEE report, with a signal electrode on the top of a finger and a ground electrode closer to the wrist 11 separately controllable tactile zones across five fingers and the palm can be stimulated.
Because the palm and finger pads are much more sensitive than the backs of hands, the team were able to produce sensations in the front of the hand without the user feeling anything in the back of the hand, even though that was where the electrode was attached.
Researcher Pedro Lopes told IEEE: “Electrotactile stimulation does not feel exactly like a real touch. But on contact, it does feel like a tap on my skin, which is pretty realistic.”
The paper, which will be presented at the 2023 Conference on Human Factors in Computing Systems, holds out the promise of haptic wearables that can stimulate touch sensations in the user without the need for a hardware layer.