Book excerpt: This unique volume presents the scientific progress, state-of-art technology, and thrust areas to be focused in electrorheology (ER) and magentorheology (MR). In the last couple of years, this area produced significant impacts on automobile industry, bridge and building construction, aerospace industry, and defense industry. Recent innovation in this area lead to new technology, which has great impact on energy production and energy conservation. This book includes all papers presented at the 12th International Conference on ER Fluids and MR Suspensions, held in Philadelphia, USA, August 16 to 20, 2010, providing a comprehensive overview of this flourishing area. It is an essential source of reference for chemists, engineers, physicists, and materials scientists. It is also suitable for science and engineering students.