Power analysis for the design of a large area ultrasonic tactile touch panel

Abstract

Tactile interfaces are intuitive but lack of haptic feedback. One method to provide tactile feedback is to change the friction coefficient of the touch surface. Several small-size tactile devices have been developed to provide programmable friction coefficient based on the squeeze air film effect. This effect is produced by ultrasonic vibration of the tactile plate thanks to piezoceramics. In order to design larger embedded tactile feedback areas, a key issue is the power consumption. In this paper, we present the power analysis of a tactile device which is based on the squeeze film effect. We first investigate the source of power consumption by a series of measurements. Then, an analytical model is developed to estimate the power, which gives the conclusion that, when the vibration amplitude is constant, the power consumption is not related to the number of piezoelectric actuators. According to this result, we design a large area (198mm × 138mm) tactile plate with only eight piezoelectric actuators. Experimental results show that the power consumption of the large tactile plate is less than 2 Watts. Moreover, we also find that the power consumption of the large tactile plate was predictable with the measurement results from small plates with an average error of less than 10%.