Need help with my A-Z book?

[Maximum7]

I've been on this forum a lot lately, asking about future ideas for my sci-fi civilization. I was planning on making a RPG type game, but it isn't coming together so well, so I'm putting it on ice for now. Instead, I want to make a A-Z book of futuristic inventions. One invention for each letter of the alphabet. I was thinking of making a children's book to get kids into science; but I want to be creative and not just put obvious stuff like A is for Antimatter rocket. I want it to be creative.