If there's a great woman behind every successful man, then there's a shrewd investor behind every cutting-edge technology. And if you're working within the American scientific community, that investor is likely to be Dr Arun Majumdar, head of the Advanced Research Projects Agency – Energy, otherwise known as Arpa-E.
Born in Calcutta and educated in Mumbai, the former Professor of Mechanical Engineering at The University of California, Berkeley, has been at the helm of Arpa-E since it was created by the US Congress in 2009 to "enhance the economic and energy security of the United States".