Robin2:
One system I saw (back in the day) for working a shears was to spin up a flywheel and when it was up to speed engage it with the cutting mechanism - the energy in the flywheel drove the cutting action....R
Similar to what Robin mentioned is to store the energy needed in a capacitor and then to make the cut, discharge the capacitor through a solenoid attached to a steel blade. A brass anvil is need to hold the filament while the blade cuts it.
Charge a large value, non-electrolytic capacitor, to say, 50 or even 100 volts dc, and discharge through a 12 or 24 volt solenoid. Very fast and powerful action, then a time to rest and cool and recharge the capacitor.
Paul