Some years ago there was talk of all engines having valves controlled electronically using solenoids. If I remember correctly helical solenoids under the name "Helenoid" where considered as producing enough power to open and close the valves, either fully open or partially open, at any point in the timing cycle.
Koenigsegg seem to be using a pneumatically operated system which is electronically controlled.**LINK**
Seems a shame that it is proposed to ban the sale of petrol, diesel and hybrid cars in the near future!
Neil