Aeroponics.

Advantages of using hydroponics or aeroponics?

High technology method - Aeroponics - is a method that do not requires soil . However this method is expensive and is not widely used. eg. butterhead lettuce grown in an aeroponics farm, where roots are not immersed in nutrient solution but are sprayed with the solution at intervals.

Yes. I have done this using an aeroponics system. Dipping in root hormone will also help the process.

An aeroponics system is defined as a system that supports the growth of plants in an air medium. An aeroponic system was prominently displayed in the Star Trek Voyager series.