File:VHP - Vibrotactile Haptics Platform for On-body Applications.pdf

English: Wearable vibrotactile devices have many potential applications, including sensory substitution for accessibility and notifcations. Currently, vibrotactile experimentation is done using large lab setups.

However, most practical applications require standalone on-body devices and integration into small form factors. Such integration is time-consuming and requires expertise.

With a goal to democratize wearable haptics we introduce VHP, a vibrotactile haptics platform. It includes a low-power miniature electronics board that can drive up to 12 independent channels of haptic signals with arbitrary waveforms at a 2 kHz sampling rate. The platform can drive vibrotactile actuators including linear resonant actuators and voice coils. The control hardware is battery-powered and programmable, and has multiple input options, including serial and Bluetooth, as well as the ability to synthesize haptic signals internally. We developed current-based loading sensing, thus allowing for unique features such as actuator auto-classifcation, and skin-contact quality sensing. Our technical evaluations showed that the system met all our initial design criteria and is an improvement over prior methods as it allows all-day wear, has low latency, has battery life between 3 and 25 hours, and can run 12 actuators simultaneously.

We demonstrate unique applications that would be time-consuming to develop without the VHP platform. We show that VHP can be used as bracelet, sleeve and phone-case form factors. The bracelet was programmed with an audio-to-tactile interface and was successfully worn for multiple days over months by developers. To facilitate more use of this platform, we open-source our design and plan to make the hardware widely available. We hope this work will motivate the use and study of vibrotactile all-day wearable devices.