Facebook's "Tactile Echoes" Wearable Aims to Bring Novel Feedback to Augmented Reality

A trio of researchers working with Facebook Reality Labs have showcased a wearable system for augmenting tactile interactions in augmented reaity: Tactile Echoes.

"We present Tactile Echoes, a wearable system for augmenting tactile interactions with any object," the researchers write in the abstract to their paper. "This system senses vibrations in the fingertip that are produced by interactions of the finger with a touched object."

"It processes the vibration signals in real-time via a parametric signal network and returns them to the finger as 'Tactile Echoes' of the touch interaction. Just as acoustic echoes continuously respond to sound, Tactile Echoes are continuously generated in response to the sensed tactile contacts."

Exactly what form a "Tactile Echo" takes depends on the interaction: Tapping briefly with a finger will produce discrete echoes, while sliding along a surface creates continuous feedback. The echoes are presented in two forms simultaneously, for multisensory feedback: Tactile and auditory.

"Many different effects can be designed using ten signal processing parameters," the researchers explain. "Distinct effects may be assigned to different touched objects or surface regions by sensing the hand location in a mapped environment."

The Tactile Echoes platform is based on a piezoelectric sensor and actuator worn on the user's finger. Output from the sensor is passed through an amplifier to the audio interface of a PC, along with tracking data about its location; the output from the audio interface is then passed through an amplifier of its own and on to the actuator, creating the echo.

"Participants rated what they felt using descriptors that were provided by participants," the paper explains of the technology's testing. "This culminated in an MDS analysis that suggested that the perceptual space of the designed stimuli can be approximated as two or three dimensional, and further suggested that this space could be associated with descriptors including wobbly or rumble, which evoke the idea of a dynamic touch interaction, or with terms like rubbery, that evoke a change in material properties."

There are aspects which need to be viewed critically, the researches admit: Participants found the feedback synthetic or "cartooned," and there's presently no way to easily design stimuli with a small number of parameters.

The full paper is available under open-access terms on the Facebook Research website, following its presentation at the IEEE World Haptics Conference. IEEE Spectrum has more.