A Multi-User Surface Visuo-Haptic Display Using Electrostatic Friction Modulation and Capacitive-Type Position Sensing

Abstract

This paper proposes a visuo-haptic feedback system that can provide haptic feedback to multiple users on an LCD monitor using electrostatic adhesion and built-in capacitive sensors. The prototype system consists of a 40-inch LCD monitor, an ITO electrode sheet arranged on the monitor, and multiple contact pads for electrostatic adhesion. By applying low-frequency haptic voltage and high-frequency sensing voltage to each pad, the system realizes passive haptic feedback, as well as position sensing using the same components. The passive haptic feedback force exceeds 1 N at 300 V rms. The performance of the sensing system is investigated in terms of interference, which shows the haptic voltage and existence of multiple pads can affect the sensing and can shift the output by a few millimeters. A pilot application, virtual hockey game, successfully demonstrates the sensing and haptic rendering capability of the proposed system. The effect of the interference on the demonstration is discussed.

Modeling and control of electroadhesion force in DC voltage

“…The mechanical response is caused by elastic deformation of asperity in surface roughness [21] and macroscopic deformation of the electrodes/insulators [17]. In the previous study, the authors showed that the mechanical responses can be compensated by estimating the equivalent gap by using a built-in sensor that measures the capacitance of the paired plates [18].…”

“…The behavior of interdigital electrodes in the context of electroadhesion has recently been studied extensively [8,11,12]. Electroadhesion has also been applied to surface haptic displays [13][14][15][16][17][18], in which electroadhesion modulates friction on a transparent electrode that covers an LCD surface, to create haptic effects. In those haptic applications, planar electrodes have been preferred, rather than inter-digital electrodes.…”

Interaction force estimation on a built-in position sensor for an electrostatic visuo-haptic display

“…To extend the possibility of haptic feedback on an LCD, the authors have proposed an indirect electrostatic visuohaptic rendering system that can provide large haptic feedback force to multiple users or fingers [9][10][11][12], without using Johnsen-Rahbeck effect. The proposed system utilizes "contact pads" that have electrodes on their bottom surfaces.…”

“…The user obtains haptic feedback via the contact pads, and therefore, the rendering method is called "indirect". One of the prototypes, which is used in [10][11][12], is shown in Fig. 1.…”

“…The prototype systems detected the positions by superposing sensing signal on the haptic voltage; the positions were estimated in a similar manner as surface-capacitive-type touch-screens. Using the position sensing capability, the previous studies demonstrated a hockey game with haptic feedback, in which users can feel impact when hitting a puck or can feel walls of the hockey arena [10,12].…”