Students, especially tweens and teens, love thinking about inventions. They are fascinated with "the possible" and this lesson really motivates them.
This is a cool lesson about "Game Changers" where students brainstorm great inventions and discuss/debate and rank them.
It goes with this Gif Book students can review and study.
This is a nice ppt presentation that has 3 videos about 3 new inventions. Ask your students to watch and then debate the pros/cons of each. Links to videos in the ppt attached.
Also see these two great Gif Books about inventions and the attached handout of exercises.