Soft Nanocomposite-Based Pressure Sensors as Smart Seals

Mechanical seals play a critical role in the functionality of diverse joint mechanical elements and solid structures. Their main functions are the prevention of mass transfer, maintaining stable pressure between the joints, as well as avoiding external contamination. Yet, current sealing technology is unable to provide a sealing solution in which the pressure applied between the mechanical elements is monitored to ensure sealing functionality. In this work, the use of square-shaped nanocomposite sensors made of polydimethyl-siloxane (PDMS)/carbon nanotubes (CNT) encapsulated in neat PDSMS is investigated and its performance against high pressure is evaluated. The sensing behavior was found to be significantly different depending on the pressure level (below or above 1.5 MPa), while adjusting the CNT content improves the sensitivity at higher loads. This kind of smart seals based on nanocomposite pressure sensors can be applied in different fields of industry, such as manufacturing, automotive, aerospace and even energy as smart seal for monitoring in-between plates' pressure in hydrogen fuel cells.