This is a great idea. It would be wonderful to expand this at other grade levels. As a middle school teacher I have seen the same ideas from students. Many students think it is either Einstein or other males that are scientists. We need to reinforce that contributors to fields of science are from all walks of life and not always from traditional science fields.
Maker mystery bags. Put a bunch of stuff in a brown lunch bag and see what can be created with the supplies. The supplies in the bags could be duct tape, origami paper, conductive tape, LEDS, straws and batteries with LEDS. Something along these lines would allow them to be creative and has minimal mess and cleanup. They could even put their projects back in the "lunch" bags and work on them multiple days. When completed put the completed project in the bag and have a drop off point so that projects could be displayed for inspiration for others. And of course lots of photos. The idea of having students being the keepers or masters so to speak is a great idea. This provides for ownership and encourages others to step up and take that responsibility. This is an interesting concept and am interested in how its progresses. This is similar to Kevin's Lunch Bunch.