Japanese YouTuber Kurahito Craft made a completely functional and sturdy cushion entirely out of wood. the screenshot above illustrates how. By cutting notches into opposing sides of the columns, he used the material's natural flexibility to create springs. When all 60 wood springs are bound together and capped, they combine into a flexible cushion that doesn't break under pressure.
To put his design to the test, Kurahito stood on the assembled cushion with his full bodyweight, as well as gradually reduced the number of springs down to only four. So as long as the springs are prevented from flipping sideways, they hold up well.
-via The Awesomer