Design and Implementation of a Technique for a Capacitive Touch Screen

This paper presented the design and implementation of a technique to transmit information through a capacitive touch screen. The key idea is to exploit the pervasive capacitive touch screen and touchpad input devices as receivers for an identification code transmitted by hardware identification token. While the token can take many forms, we consider here an example realization as a ring, inspired by the signet rings used since ancient times. The token transmits electrical signals on contact with the screen; direct either contact or indirect contact through the human skin. This paper introduces and explores the concept of capacitive touch communication as one mechanism to distinguish users.  Showing how the output of an off-the-shelf touch screen system can be affected by electrical signals generated in a token that is in contact with the screen. We also show how such signals can be transmitted through the human skin. This paper design and implement a prototype transmitter in the form of a signet ring and receiver software for communicating short codes through an off-the shelf capacitative touch screen.