A Revolution in Haptics

 An area we worked in within innovation labs with consumers, how do products feel in context?

A Revolution in Haptics  By Paul Marks Commissioned by CACM Staff, February 3, 2022

Force-feedback devices like haptic gloves and gaming vests, which are peppered with electrically driven actuators, let people feel they are actually touching, or being touched by, three-dimensional (3D) objects in virtual reality (VR).

Making 3D visuals tangible does not always have to involve the use of such complex wearable technology, say three research groups that have come up with some intriguing – if not downright bizarre – new ways for people to interact with virtual environments.

Alternative haptic methods are needed, says Pedro Lopes, who leads the Human-Computer Integration Lab at the University of Chicago, because haptic gloves and vests are bulky, power-hungry and hard to build force-feedback motors into. "So people in our field, and in the haptics, VR, and AR (Augmented Reality) industries, need to bend the laws of physics and propose new types of actuators that consume less power and which are easier to integrate."

In attempting to engineer such a system, Lopes and his Ph.D. students Jasmine Lu and Jas Brooks have come up with a pretty radical idea: their new take on haptics applies a variety of chemical stimulants to a user's skin to evoke sensations related to the content that's playing out in a VR story or a game at any time.

To apply their stimulants, the team developed a prototype wrist-worn silicone sleeve, and a cheek patch for facial application, which use micropumps to apply to the skin topical skin-safe dosages of one of five chemicals, some of which sound like they'd be more at home in television medical shows like ER, Grey's Anatomy, or House:

They apply lidocaine to induce a numbing sensation; 

Szechuan pepper to create a tingling feeling;

A cinnamon-derivative, cinnamaldehyde, stings;

The chili pepper derivative, capsaicin, warms the skin, and

Menthol provides a cooling sensation.

"By having the receptors in your skin generate the haptic sensations, we don't need bulky heating and cooling devices; we just need to deliver a few drops of a chemical stimulant, and your skin does the rest," says Lopes.

To test the idea, they developed a VR experience with a storyline about a failing nuclear reactor – and tested it on four Oculus Quest VR users wearing their chemical haptics kit, with a chemical reservoir behind the VR helmet. The narrative included a shorting-out reactor control panel, which produced sparks that excited the tingling sensation on the arm – and as people ran outside, the cooling chemical was applied to the face patch. The failure of a VR arm interface that controlled a door in the story was reinforced, emotionally, by numbing the user's arm with lidocaine, and a VR "wound" actuated the stinging stimulant. Finally, as a reactor door opened, the heat issuing from it was registered by the warming stimulant.  .... '