Introduction
Increasing transportation and other industrial activities since the beginning of the last century have been consuming much of our non-renewable energy resources (like petroleum) day by day, and a significant portion of the energy produced is spent overcoming friction in moving mechanical systems. More important, much of the fuel used to generate energy turns into CO2, which contributes to climate change and could have dire consequences [1]. Accordingly, more effective control or reduction of friction in moving mechanical systems is very important for a sustainable future.