Hi Narendran Ashok
While looking for good quality, don’t forget that piezo needs impact forces to deform, i.e., the charge generated is proportional to force applied. Even if you have diamond-like quality, unless you provide a good amount of force, it’s useless. So design something that will multiply forces, like a spring assisted striker.
Piezo is extensively used in tank and artillery ammunition. It won’t explode if you hit it with a hammer. It’ll need magnitude a thousand times as much as that.