Innovation of Pencil Lead Drawn Paper Sensors (PLDPS) Using Electrical Resistance (ER) Measurement: II. Load, Micro-Damage, and Thermal Sensing on Composites by PLDPS.

This paper describes a new type of sensor that can monitor electrical signals for external stress or damage and heat transfer. It is composed of conductive pencil lead graphite, which is sensitive, affordable and easy-to-handle. This work was to detect mechanical damages in composites using Pencil Lead Drawn Paper Sensor (PLDPS). To measure electrical resistance (ER) via bending, by narrowing the distance between glass plates attached with PLDPD, ER increased stepwise while ER decreased with widening the distance reversely. The PLDPS can easily change the shape in a rectangular vortex. ER change responded well in tensile and flexural tests, while it showed leveling off under cyclic compression. Two-dimensional ER mapping was used during impact, drilling and heat transfer tests for detecting damage and thermal transfer. Compared to strain gauges, PLDPS can be applied inexpensively to detect damages successfully under various mechanical tests. [ABSTRACT FROM AUTHOR]