Paper Reading #14: TeslaTouch: Electrovibration for Touch Surfaces

Reference Information

TeslaTouch: Electrovibration for Touch Surfaces
Olivier Bau, Ivan Poupyrev, Ali Israr, Chris Harrison
Presented at UIST'10, October 3-6, 2010, New York, New York, USA

Author Bios

• Olivier Bau is a Post-Doctoral Research Scientist in Disney Research in the Interaction Design group. His PhD is in Computer Science and was received from INRIA Saclay.

• Ivan Poupyrev is a Senior Research Scientist in Disney Research in the Interaction Design group and studies interactive technologies and interface design.

• Ali Israr has a PhD in Mechanical Engineering from Purdue and now works in the Interaction Design @ Disney group in Disney Research. His interests are in disseminating haptic technologies in consumer-grade products.

• Chris Harrison is a PhD student at Carnegie Mellon's Human Computer Interaction Institute. He is also a Microsoft Research PhD Fellow and focuses his research on novel interaction techniques.

Summary
Hypothesis
The principle of electrovibration offers an advantageous alternative to current tactile interfaces for touch surfaces.

Methods

A study was conducted with subjective evaluations to better understand how users interpret the tactile sensations produced by TeslaTouch.Ten participants felt four TeslaTouch textures produced by four frequency-amplitude combinations: 80 Hz and 400 Hz each at 80 and 115 Vpp. Then they were asked to fill 3 different set of questionnaires about the quality data and constraints of tactile feedback.

To determine the absolute detection threshold participants were provided with a divided screen with tactile feedback on one part and asked to determine which part provided tactile feedback. The screen was provided with a varied level of voltage for 12 reversals.

To determine the The frequency and amplitude discrimination threshold a study was done similar to the previous one.Three tactile stimuli were presented one after another. Participants were requested to identify test stimuli, which was different from the two identical reference stimuli.The session was terminated after 12 reversals at the smaller step size.They were requested to wear an electrostatic ground strap on their dominant forearm and slide the pad of their index finger on the interactive surface.

Results
From the subjective evaluation, higher-frequency stimuli were perceived as smoother compared to lower frequencies, with descriptions like "paper" versus "wood".  They found that the effect of amplitude depended on the underlying frequency.  Increasing amplitude for high frequencies caused an increase in the perceived smoothness, where for low frequencies it caused an increased in perceived stickiness.   In determining the detection thresholds and amplitude discrimination thresholds, they found that frequency had a very significant effect on determinable threshold, and that frequency seems to have little effect on amplitude JND.

Contents

The paper presents the principles and implementation of electrovibration-based tactile feedback for touch surfaces. It also reports the results of three controlled psychophysical experiments and a subjective user evaluation, which describe and characterize users’ perception of this technology. It also analyzes and compares the design to traditional mechanical vibrotactile displays and highlight their relative advantages and disadvantages. As well as exploring the interaction design space.

Discussion
I did not like this paper at all. I thought that Tesla Touch was ridiculous because of one fairly major reason, it can't be used with capacitive touch. The entire world has standardized on capacitive touch and using a system that relies on electricity running across the surface of these screens would render it useless.