Icarus Dash is one of the experimental augmentations, which can be unlocked after meeting Vaclav Koller in the main quest Getting in Top Shape Again. You also have to buy an upgrade to this augmentation - Charged Dash. Once you do that, find an enemy and charge the augmentation completely before you activate it.
A little note here - in order to get the achievement, enemy NPC should be engaged in a fight with you - the achievement won't pop if you will sneak up from behind and use the dash on an unaware enemy. So the best approach is to "ambush" an enemy that is patrolling - take a position and start charging the dash once he's close to spotting you, once he does and engages you - ram him and voila!