SawStop saws use a small explosive charge to jam the rapidly spinning blade into the moral equivalent of a brick wall. It destroys the explosive, the blade, and the wall, and you have to replace the whole set at a moderate expense from SawStop - this is their subscription revenue model, because of course it sometimes falsely triggers.

There are more reusable alternatives now but I don't remember what they're called. For a while SawStop was the only game in town.