Kevin Warner Flanagan

Ultrahigh barrier coating deposition on polycarbonate substrates

The use of polycarbonate film substrates enables fabrication of applications, such as flexible display devices, lighting devices, and other flexible electro-optical devices, using low cost, roll-to-roll fabrication technologies. One of the limitations of bare polycarbonate material in these applications is that oxygen and moisture rapidly diffuse through the material and subsequently degrade the electro-optical devices. This article summarizes recent results obtained at GE Global Research to solve the oxygen and moisture diffusion issue. It will be shown that through the application of thin, dense, plasma-based inorganic coatings one can significantly reduce the oxygen and moisture permeation rate through polycarbonate films. However, as a result of defects that are commonly present in these inorganic coatings there is a limit to the performance of such barrier coatings. To further improve the barrier performance, advanced barrier coatings comprising both inorganic and organic materials have been developed. Both modeling and experimental results will be presented that explain why these hybrid material barrier coatings are capable of reaching ultrahigh barrier performance.

High temperature nanocomposite insulation for high power density machines

Increasing demand for higher power, lighter weight and compact power generation systems in aircraft has resulted in the need for a new high temperature insulation system. It requires better thermal capability and improved reliability over the 240°C system used commercially. A 280°C insulation system has been developed based on a hybrid organic-inorganic material to address these evolving requirements. This electrical insulation system comprises a nanocomposite polyimide wire for windings, and a hybrid slot liner for ground wall insulation. Thermal, electrical and mechanical properties of this insulation system will be discussed.