Modern Steam Engine?

I am currently watching a TV programme on BBC1 called “Fred Dibnah’s Age of Steam”. My crazy thought whilst watching it was the following.

This all our modern knowledge and technology, I can’t help but wonder what a Steam Engine would look like if it was designed and built today. How efficient would it be? Would modern material like Carbon Fiber, Kevlar, etc be used? Is there computer systems that could be used to design it? Or is this just too crazy? (Please give me credit if you ever do decide to design/build a modern engine and was inspired by my ramblings)