Micro needling causes collagen response via the "injury" of the needles themselves, whereas RF micro needling uses both the mechanical response from the needles AND the radio frequency energy which creates an elevated response by heating the tissue beneath the top layers. (This "beneath the surface" action is what makes RF microneedling an ideal choice for skins with more pigment or more pigment potential.) RF Microneedling devices have programmed settings to insure you don't have too much heat within the tissue. The simpler devices may only target one depth, while newer devices have the capability of multiple insertion depths - this to include more tissue heating. The needles are the "avenue" for the radio frequency energy, so the more areas those needles visit, the more response you'll get. With some devices you'll only have one possible depth of penetration; others offer more options. One of the aspects of microneedling that most people are unaware of (though the doctors know!) is what's called impedance. This is simply the resistance your skin offers and this resistance varies over the area being treated. Our practice has opted for an RF microneedling device that detects levels of impedance, so the RF delivery is adjusted, making sure your skin receives consistent energy during the treatment. It's a novel concept and one that's employed to give the most predictable outcomes. The idea is to get the appropriate amount of energy - not too little nor too much.