LightTouch: Passive Gadgets for Extending Interactions on Capacitive Touchscreens by Automating Touch Inputs.

We present LightTouch, a passive gadget to enhance touch interactions on unmodified capacitive touchscreens. It simulates finger operations such as tapping, swiping, or multi-touch gestures using conductive materials and photoresistors embedded inside the objects. The touchscreen emits visible light and the photoresistor senses the level of this light, which changes its resistance value. By controlling the screen brightness, it connects or disconnects the path between the GND and the touchscreen, thus allowing the touch inputs to be controlled. In contrast to conventional physical extensions for touchscreens, our technique does not require continuous finger contact on the conductive part nor the use of batteries. Our technique opens up new possibilities for touch interaction such as for enhancing the trackability of tangibles beyond the simple automation of touch inputs.