What is the fine-grained topic of the following text: Previous winners include a team of engineers from the University of Nottingham and Teledyne e2v for developing MicroHammer, a revolutionary process for extracting copper from its ore using microwave technology, as well as Professor Sriram Subramanian and the team behind Ultrahaptics, a new company developing invisible control systems constructed from ultrasound. Only return the topic.
Innovative technological developments and their creators