Electrical and piezoresistive properties of DLC with conductive nanoparticles for applications as a sensor material in strain gauges in space structures

Abstract

Diamond-Like Carbon (DLC) films have been extensively applied as a coating in different fields due to their excellent mechanical, chemical and tribological properties. The incorporation of metals in a-C:H films can significantly enhance these properties, expanding their applications as a sensor material in strain gauges. The film with metals (a:C-H:Me) can change the DLC electrical properties and ensure a low temperature dependence. Therefore, in this work a:C-H:Me film will be growth via two different systems. The first system will be used in Brazil via a Plasma-Enhanced Chemical Vapor Deposition (PECVD) modified with an additional cathode. In this case, metallic nanoparticles dispersed in a colloidal solution will be incorporated in the growth chamber via a controlled pulsed valve. The second system will be used at Fraunhofer institute via a combined PECVD/Physical Vapor Deposition (PVD) system using a target as a metal source in an Ar/C2H2 atmosphere. The film obtained from both processes will be characterized in order to apply as a sensor material in strain gauges for application in space structures. Therefore, the films piezoresistive properties will be studied, such as gauge factor and temperature coefficient of resistance; to obtain a high strain sensitivity and a low temperature dependence. Besides, other films properties will also be analyzed, such as chemical composition, morphology, thickness, resistivity, structural quality and compressive stress. (AU)