How can I expand my personal inventory?

I don't even know if this is possible but I'd love to do so as I always end up having to go back to my base a lot of times when I go mining.

It is currently not possible to add more inventory spaces to your backpack. As other have stated, you can carry storage with you to be able to transport more items, but the backpack size is fixed.

just bring a rover with a storage unit on it or possibly (for a lot of inventory) link up trucks together and bring them to the mine entrance. That's what I do whenever I want to bring a bunch of research units back to my base from the mines. Works quite well. But as of now, there is no way to expand your personal inventory

If you can make "storage" from a printer, each of those will go on top of the "storage" which you can build on a vehicle, so instead of having 8 storage spaces, you now have what... 24? I'm too lazy to do the math, but each printer storage piece has 8 spaces on it. That takes up 2 of the spaces on a truck. It's really nifty.