The University of Pennsylvania created these modular robots that are able to recognize each other and assemble themselves into 1 larger robot. Once assembled, the larger robot is able to walk…theoretically. A video of the bot in action is available here.
Take a minute to look at Crabfu SteamWorks. A site run by I-Wei Huang who does work with robotics powered by steam. I tip my hat to this guy for really getting the idea behind merging old and new tech.