From the article:
"This kind of design wouldn’t work with conventional aircraft engines because 10 engines would be way too heavy. But electric motors can be made extremely small and light, allowing even a car-size vehicle to have 10 of them."
"This kind of design wouldn’t work with conventional aircraft engines because 10 engines would be way too heavy. But electric motors can be made extremely small and light, allowing even a car-size vehicle to have 10 of them."
You also can't put combustion engines in the end of small actuators, like it's on the article.
The benefit of electric is the ability to very quickly alter thrust for that quad-rotor type of control.