  In this report, the contact resistance between "electrode" and "lead" is
investigated for reasonable measurements of samples' resistance in a
polypyrrole (PPy) nanowire device. The sample's resistance, including
"electrode-lead" contact resistance, shows a decrease as force applied to the
interface increases. Moreover, the sample's resistance becomes reasonably
similar to, or lower than, values calculated by resistivity of PPy reported in
previous studies. The decrease of electrode-lead contact resistance by
increasing the applying force was analyzed by using Holm theory: the general
equation of relation between contact resistance ($R_H$) of two-metal thin films
and contact force ($R_H$ $\propto$ $1/\sqrt{F}$). The present investigation can
guide a reliable way to minimize electrode-lead contact resistance for
reasonable characterization of nanomaterials in a microelectrode device.
