title: Polarity effect in electrovibration for tactile display.
abstract: Electrovibration is the tactile sensation of an alternating potential between the human body and a smooth conducing surface when the skin slides over the surface and where the current is too small to stimulate sensory nerves directly. It has been proposed as a high-density tactile display method, for example to display pictographic information to persons who are blind. Previous models for the electrovibration transduction mechanism are based on a parallel-plate capacitor in which the electrostatic force is insensitive to polarity. We present experimental data showing that electrovibratory perceptual sensitivity to positive pulses is less than that for negative or biphasic pulses and propose that this disparity may be due to the asymmetric electrical properties of human skin. We furthermore propose using negative pulses for insulated tactile displays based on electrovibration because their sensory thresholds were found to be more stable than for waveforms incorporating positive pulses.
authors.affiliation: Department of Orthopedics and Rehabilitation Medicine, University of Wisconsin, Madison, WI 53706, USA. k.a.kaczmarek@ieee.org
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Kaczmarek
authors.forename: Krishnakant
authors.initials: K
authors.lastname: Nammi
authors.forename: Abhishek K
authors.initials: AK
authors.lastname: Agarwal
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Tyler
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Haase
authors.forename: David J
authors.initials: DJ
authors.lastname: Beebe
mesh_terms: D000328:Adult; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005385:Fingers / Q000502:physiology*; D006801:Humans; D012684:Sensory Thresholds / Q000502:physiology*; D012867:Skin / Q000294:innervation*; D012879:Skin Physiological Phenomena; D014110:Touch / Q000502:physiology*; D014159:Transducers; D014584:User-Computer Interface; D014732:Vibration