Facebook Designs a Wrist-Worn Haptic Feedback Device for AR/VR Applications

While the majority of haptic feedback devices are handheld controllers, some companies and academic institutions are developing gadgets that can be worn, including Facebook Reality Labs' Tasbi — a squeeze and vibrotactile feedback wristband. Tasbi (Tactile and Squeeze Bracelet Interface) was unveiled last year at the World Haptics Conference and looked like a set off small boxes connected to a central band with an oversized compartment that houses a haptic actuator.

The design is much more than a simple band and uses a combination of vibrations and dynamic tension adjustment to mimic haptic feedback with AR and VR objects. Tasbi was made using six “vibrotactors,” each containing a linear actuator that allows for precise vibrational feedback. The vibrotactile units are clipped into elastic sidings with secure lids. The primary squeeze mechanism is outfitted with a 12mm DC motor and a 13mm Harmonic Drive gearbox, which drives a two-sided spool to generate tension in a UHMWP cord to create squeeze forces.

Collectively, the vibrotactors and primary squeeze mechanism provide vibration and squeeze cues based on the digital objects the wearer interacts with, such as vibrating from side to side to indicate contacts, collisions, or interfacing with textures. Vibrations can also move front to back (or vice versa) to suggest springiness of buttons and weights. Tasbi enables users to interact with visible illusions like holograms, providing a sense of differential feedback.

Tasbi doesn’t offer any finger tracking or tracking of any kind, for that matter. It doesn’t contain any control hardware either. Instead, it shifts AR/VR tasks over to a host PC using a Quanser Q8-USB digital acquisition (DAQ) board and C++-based Mechatronics Engine and Library. The researchers state that miniaturization would let them incorporate wireless capabilities, and add onboard batteries, which would cut the connection cord to the PC.