Cellulose paper and Pencil based Smart Switch

The fabrication and characterization of a paper and pencil based resistive touch sensor is carried out in the present work. The sensor detects the effective change in the resistance, when the finger is placed on it. An ash less, low cost, easy to access, bio-degradable, flexible, light weight, easy to fabricate and ultra-thin sensor is developed by drawing interdigitated graphite electrodes on the Whatman filter paper of grade 42. Change in the resistance is due to the path created for flow of electrons, when the finger is placed. Current versus time and $\Delta$ R/Ro versus time characterization of fabricated device is done using Keithley 2450 source meter. Response of the device has made noticeable changes for the finger contact. The measured resistance of the non-touch and touch is found to be 80.154 M $\Omega$ and 4.748 M $\Omega$ respectively. This huge change in resistance is sufficient to detect the touch. The performance and sensitivity of the proposed sensor are evaluated using the test circuit and smart switch is developed on paper substrate.