I know active STEM is happening in my classroom when my senior students are teaching robotics to younger students.
This have been amazing...
Last fall I starting bring some of my grade 11 and 12 students into elementary school to run day camps with elementary classes. My students learned about the robotics system we were using and then visited classes at various school teaching other students about robotics.
My students would break up and work with small groups building a robot over the course of the day and then finished with a small competition. The elementary students loved it. Often, the students would completely ignore the bells and keep working into break. If was an awesome experience.
Here is a link to a video a local new outlet did on one of the camps: https://www.sootoday.com/videos/news/robots-take-over-local-classroom-77324