We always like new ideas–keep them coming. But the electrodes do have to be solid in a Mather-style DPF. If you eliminate the anode, the currents in the center will pinch together as soon as the current starts flowing, so you would need a much larger radius insulator to slow that down. If you put the insulator at the edge of the vacuum chamber, you get a Fillipov-style DPF. You don’t really need any pre-ionization, but you have less flexibility of design and you need a lot more energy for the same current.
