Ultrathin Multifunctional Graphene-PVDF Layers for Multidimensional Touch Interactivity for Flexible Displays

Abstract

This paper presents a flexible graphene/polyvinylidene difluoride (PVDF)/graphene sandwich for three-dimensional touch interactivity. Here, x-y plane touch is sensed using graphene capacitive elements, while force sensing in the z-direction is by a piezoelectric PVDF/graphene sandwich. By employing different frequency bands for the capacitive- and force-induced electrical signals, the two stimuli are detected simultaneously, achieving three-dimensional touch sensing. Static force sensing and elimination of propagated stress are achieved by augmenting the transient piezo output with the capacitive touch, thus overcoming the intrinsic inability of the piezoelectric material in detecting nontransient force signals and avoiding force touch mis-registration by propagated stress.

A force–voltage responsivity stabilization method for piezoelectric-based insole gait analysis for high detection accuracy in health monitoring

“…[38][39][40][41][42] In the constructed piezoelectric insole device, one PVDF film was settled as the intermedia layer with top (sensing) and bottom (ground) electrode layers on and underneath it. A PET/Cu/PVDF/Cu/ PET [41][42][43][44][45][46][47][48] structured device was integrated with the electrode substrate layers. At the sensing electrode layer, 36 round (radius = 5 mm) individual sensing locations (as shown in Figure 3) were patterned to reflect major gait information during walking.…”

A Piezoelectric Force Sensing Glove For Acupuncture Quantification

“…It offers a mechanic-electronic conversion, which potentially applies to various fields from wearable electronics to medical instrument [8]. Conventional piezoelectric materials include PVDF [9][10], ZnO [11], BaTiO3 [12], and PZT (Pb based Lanthanumdoped Zirconate Titanates) [13]. Considering that the manipulation of acupuncture requires a long term needle manipulating as well as rapid response, piezoelectric PVDF-film, which presents both an advanced dynamically mechanic-to-electronic interaction and soft material property, stands out of the crowd.…”

A Force–Voltage Responsivity Stabilization Method for Piezoelectric Touch Panels in the Internet of Things

“…In an IoT architecture, the human machine interface (HMI) is a fundamental element. Among various HMI techniques that have been developed, the force touch based three-dimensional interactivity has gained interest, in view of high force detection sensitivity, passive mechanical-toelectrical conversion ability and simple readout circuitry [3][4][5][6]. However, the successful use of force touch in commercial products has rarely been reported.…”