Can Springs be used in Vex robotic competiton starstruck ?

I know Rubber bands can be used but can I use springs?

Correct, rubber bands are legal. Springs are not legal in VEX, unless you take out springs from the old VEX clutches. Inside each VEX clutch is a tiny spring that can be used for anything you like.

Bryon has said everything there is to it, but as a side note, depending on the intended application, there are other springy materials you could potentially use, for example a strip of polycarbonate when bent/under force will want to spring back to its original shape.

It may have changed but my recollection is that the clutch spring can not be cannibalized. I think the only legal spring for competition is the spring in the claw.

Yes they can be.

Latex tubing 275-1262 can be used as an elastic spring. Also there is a spring in the claw.

Anything non electrical or pneumatic can be “cannibalized”.

A good example can be found here.

Is there any videos of mechanisms in which springs are used? I’m having trouble figuring out how a tiny springs could be useful.

Here’s one:
GER Toss Up Ratchet Mechanism

And don’t forget, you can “stack” multiple springs on top of each other to make 1 big one.

Thanks you all!!!