Blog Home

Emoband strokes and squeezes your wrist

Arduino TeamMay 11th, 2023

Modern consumer devices are fantastic at providing visual and auditory stimulation, but they fail to excite any of the other senses. At most, we get some tactile sensation in the form of haptic feedback. But those course vibrations do little more than provide an indication that something is happening, which is why researchers look for alternatives. Developed by a team of City University of Hong Kong researchers, Emoband provides a new kind of tactile feedback in the form of stroking and squeezing of the user’s wrist.

Emoband looks a bit like an over-sized smartwatch with three bands. Two of those bands are just normal straps that secure the device to the user’s wrist. The third band, in the middle, can be made of several different materials. It attaches to two spools on the device, which can reel in or out the material. If both reel in the band, then it will squeeze the user’s wrist. If one reels in while the other reels out, then the band strokes the user’s wrist. Depending on the material, those sensations may elicit different emotional responses from the user.

The prototype Emoband unit uses an Arduino Mega 2560 board to control two servo motors that turn the spools for the material band. A laptop communicates with the Arduino through serial, telling it how to move the band to mirror the onscreen content. Two load cells provide feedback on the amount of squeezing pressure. The prototype device’s frame and spools were 3D-printed.

In the future, it could be possible to integrate this functionality into the smartwatches that people already wear—if the general public decided that they want this kind of tactile feedback. Initial testing showed the users certainly noticed the feedback, but it isn’t clear if they thought it was worthwhile or practical. More details on the project can be found in the researchers’ paper here.