Can you help me invent stuff?

I’m looking for inventions, real or made-up, to draw as a 50-euro-reward for my crowdfunding. Can you help?

I could draw the invention of the wheel, that’s an easy one. Or the invention of night blinds - a totally black drawing would suffice. :D

But I won’t shy away from drawing more complicated inventions. Such as the, um, yes, what?

Here’s an example of a self-invented machine I drew:

It’s the cover of my book Science: a Discovery in Comics, from 2012 - not to be confused with the science comics album I’m crowdfunding now, which will be a selection of short comics I made over 7 years for a popular science magazine. They’re in Dutch, but if you’re non-Dutch and would like to own an original drawing by me, I’ve just added an option for a mere 40 euros. And for 75 euros, I’ll throw in a signed copy of the science book from 2012!

(The Science book has been out of print for a while now, but I still have a few copies lying around and will gladly sign one for you)

Here’s the link to my crowdfunding - it’s in Dutch but there’s a button in the upper right corner to switch to English.

I’m looking forward to your suggestions for inventions for me to draw! Please put them in the comments below and inspire me!