Many finger sensing input devices now support proximity input, enabling users to perform in-air gestures. While near-surface interactions increase the input vocabulary, they lack tactile feedback, making it hard for users to perform gestures or to know when the interaction takes place. Sparkle stimulates the fingertip with touchable electric arcs above a hover sensing device to give users in-air tactile or thermal feedback, sharper and more feelable than acoustic mid-air haptic devices. We present the design of a high voltage resonant transformer with a low-loss soft ferrite core and self-tuning driver circuit, with which we create electric arcs 6 mm in length, and combine this technology with infrared proximity sensing in two proof-of-concept devices with form factor and functionality similar to a button and a touchpad. We provide design guidelines for Sparkle devices and examples of stimuli in application scenarios, and report the results of a user study on the perceived sensations. Sparkle is the first step towards providing a new type of hover feedback, and it does not require users to wear tactile stimulators.
Funding
Dhaptics; g1757; ERC Proof of Concept; GA640749
History
Publication status
Published
File Version
Accepted version
Journal
Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems (CHI 2017); Denver, CO, USA; 6-11 May 2016