The way it's described in the article was pretty clear that it pushes all contaminates, including solids, away from a particular zone on the membrane - and that

The way it's described in the article was pretty clear that it pushes all contaminates, including solids, away from a particular zone on the membrane - and that's where the uncontaminated water is harvested from. So no, it doesn't sound like it needs pre-filters. Obviously the fewer contaminates the easier/faster it will probably work. A simple settling tank would dramatically reduce the really big stuff and the rest sounds like it would be trivial for this tech to deal with. It's a very interesting technology!