Need a little more info; Is the air supply from say a leaf blower like on the Keene's Dryblower or is the vibrating fan connected to base of blower?
A photo of the fan would also be handy?
If you are using a leaf blower you can fabricate a simple fan to bolt to base of blower below screen. The constant air supply from the blower passing through the spinning fan interrupts the supply causing a flutter/vibration.
If you require more vibration, weld a small nut to one of the blades and the out of balance spin will increase vibration.
Any as mentioned photos will help.