Comprehensive Study of the Resistance of Pencil-Stroked Graphite on Paper Electrodes

Abstract

In this paper, we comprehensively study the electrical resistance of pencil-stroked graphite electrodes, which is a cheap electrical conductor. Thin graphite on paper (GOP) electrodes were manually fabricated by unidirectionally stroking rectangular areas defined by grids on graph paper, allowing the physical dimensions of the layer to be accurately represented. The physical dimensions of the electrode were then varied and the I–V relationship for the layer was characterized. Our findings indicate that these thin electrodes behave as ohmic conductors over the low voltage range (0–12 V), and their resistance can be quantitatively described by Pouillet’s Law [Formula: see text]. The deviation of the experimentally obtained linear I–V characteristic from the theoretical nonlinear I–V characteristic of graphite has been explained by measuring the temperature rise of the graphite electrode, which was found to be insignificant [Formula: see text] in the low voltage range. The effects of saturation level of the electrode and pencil grade on electrode resistance are also elaborated in this paper. By showing the turbostratic nature of graphite in GOP and analyzing its electronic conduction mechanism, the experimental observations have been explained theoretically. We also note the highly interesting low-energy electron dynamics in GOP reported previously in misoriented multilayer graphitic systems. We observed insignificant changes in electrode resistivity over five-minute intervals and repeated use. Hence, these electrodes exhibit great stability as a low-voltage electrical conductor. The flexibility, usability, and ease-of-synthesis of these thin graphite layers in large volumes, coupled with their remarkable electrical properties, present a novel approach for adopting them in designs of low-cost and high-performance sensors, foldable electronics, and microfluidics, paving the way for an electronics industry that can meet the stipulations of many more products.