I'm wondering whether the Ruyan unit that was tested in the new study had their patented sonic (Piezo) vaporizer, or a typical heating coil (Nichrome) type vaporiser. [/url]).
That ultrasonic element is in the original patent applications but I dont think that it has ever been built into some commercial product, despite some marketing claims. AFAIK, none of the atomizers on the market does use ultrasonic technology, including the elusive Ruyan v8. From reading some older ECF threads (here and here), it seems to me that the device is akin to the common pen style (no piezo).