Dr. Subrahmanyam has teaching and research experience spanning over 38 years in Indian Institute of Technology Madras, Chennai. Presently, he is Senior Professor (retired). His main area of research is in thin films and surface engineering, basics of plasma, and bio-medical engineering. He has established a thin-film laboratory equipped with electron beam evaporation, DC and RF magnetron sputtering, pulsed laser deposition (PLD), and sol-gel techniques. His main area is on metal oxide thin films (ITO, ZnO, WO3, VO2) spanning the industrial applications of transparent conducting oxides (TCO) and electrochromics (WO3) for smart windows. He has designed and developed a non-contact and non-destructive surface analytical tool: Kelvin Probe; presently, this machine is being commercialized. He is Author (along with Dr. Suresh) of the first book on Kelvin Probe: The Kelvin Probe for Surface Engineering: Fundamentals and Design (ISBN 9781420080773) published by Ane Books, India, and CRC Press, USA (in 2010).