A Technique for Touch Force Sensing using a Waterproof Device's Built-in Barometer

Abstract

We present BaroTouch, a technique that leverages a waterproof mobile device's built-in barometer to measure the touch force. When an airtight waterproof device is touched, the distorted surface changes the air pressure inside that device and thus changes the built-in barometer value. Although this change varies under different airtightness conditions, our technique can measure the touch force independent of the airtightness conditions. To investigate BaroTouch's characteristics, we conducted three experiments. First, since the change in the barometer value varies under different airtightness conditions, we evaluated BaroTouch's characteristics under two levels of airtightness conditions. Second, we investigated the relationship between the sensor value and the touch positions or forces and found that the touch screen increased approximately in a linear manner. Last, in a controlled user study with 10 participants, the participants could exert three levels of touch force with an accuracy of over 92.2% accuracy using BaroTouch.