Application of electrodeposited piezo-resistive polypyrrole for a pressure-sensitive bruxism sensor

This paper presents the application of the conducting polymer polypyrrole in a pressure sensitive sensor. Polypyrrole was electrodeposited on copper plates using phytic acid as a dopant and cross-linker. A combination of different polymerization durations and potentials were tested to find the polymerization conditions for thin polymer layers and homogenous surface coverage. The morphology of the surface of the polypyrrole films was examined with scanning electron microscopy to study the formation of hollow sphere beads. The polymer layers were sandwiched between two copper sheets to create pressure sensitive sensors and the piezo-resistive effect was tested. For this, increasing forces were applied to the sensors and the resistance was measured. It was found that the polypyrrole layers were pressure sensitive to pressures relevant for bruxism events and had a thickness that is suitable for application in a splint for the detection of awake bruxism. [GRAPHICS] An SEM image of polypyrrole hollow sphere beads at 20 kV and 1000x magnification.