Audio-Tactile Skinny Buttons for Touch User Interfaces

Abstract

This study proposes a novel skinny button with multimodal audio and haptic feedback to enhance the touch user interface of electronic devices. The active material in the film-type actuator is relaxor ferroelectric polymer (RFP) poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)] blended with poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)], which produces mechanical vibrations via the fretting vibration phenomenon. Normal pressure applied by a human fingertip on the film-type skinny button mechanically activates the locally concentrated electric field under the contact area, thereby producing a large electrostrictive strain in the blended RFP film. Multimodal audio and haptic feedback is obtained by simultaneously applying various electric signals to the pairs of ribbon-shaped top and bottom electrodes. The fretting vibration provides tactile feedback at frequencies of 50–300 Hz and audible sounds at higher frequencies of 500 Hz to 1 kHz through a simple on-off mechanism. The advantage of the proposed audio-tactile skinny button is that it restores the “click” sensation to the popular virtual touch buttons employed in contemporary electronic devices.

Highly pixelated, untethered tactile interfaces for an on-skin telehaptic system

“…This phenomenon can be well described by an in uence of applied preload on piezoelectric stack actuator, where strain output is enhanced with an increase in mechanical preload and the maximum strain values can be obtained at an optimum preload 48 . Above 10 V pp , the displacement is larger than the Pacinian threshold (150 nm at 200 Hz) 51,52 which is the displacement threshold. At 40 and 60 V pp operation, the displacement of the actuator under 592 kPa of pressure was 755 nm and 1315 nm, respectively.…”

Recent Advances and Opportunities of Active Materials for Haptic Technologies in Virtual and Augmented Reality

“…Reproduced with permission. [ 76 ] Copyright 2019, Creative Commons Attribution 4.0 International License. c) Hydraulically amplified electrostatic actuators using both electrostatic and hydraulic forces.…”

“…reported a flexible film‐type actuator based on a piezoelectric polymer for multimodal audio and haptic feedback. [ 76 ] The Relaxor ferroelectric polymer (RFP) based on poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) [P(VDF‐TrFE‐CFE)] was mixed with poly(vinylidene fluoride‐trifluoroethylene) [P(VDF‐TrFE)] to produce mechanical vibrations via the fretting vibration phenomenon. This PVDF‐TrFE‐based vibrotactile actuator driven by an input voltage of 200 V with 200 Hz exhibits the maximum vibration amplitude of 2.59 µm when the applied load is 40 mN (Figure 3b).…”

Low‐Voltage Soft Actuators for Interactive Human–Machine Interfaces

“…[304] Owing to the favorable characteristics of ferroelectric actuators, these actuators have been utilized for iHMI applications such as haptics or medical devices. [320][321][322][323][324][325][326] Localized tactile feedbacks have been realized through fretting-vibrotactile displays that are composed of a RFP and a top electrode while separated from the bottom electrode on a substrate by a spacer (Figure 15d). [320] To activate the display, normal pressures from the human finger push the RFP to contact the bottom electrode upon which a locally concentrated electric field is generated below the finger to induce localized electrostrictive strains.…”