Staticaponics: Water and Nutrient Delivery for Plant Growth by Electrostatic Deposition

Electrostatic deposition (ESD) is a targeted liquid deposition method that requires a high electric potential to atomize a solution flowing through a conducive nozzle, resulting in a fine spray of charged micro-droplets. In ESD, the emitted droplets result from the electrostatic breakdown from an electrostatically drawn Taylor cone. The droplets undergo Coulombic fission that decreases the ratio of the electric charge to the surface area, resulting in a monodisperse spray. The electric field directs the droplets to the rooting media and due to the large surface tension of water relatively high voltages can stabilize the spray. However, using high voltages can lead to unwanted corona discharge. Fortunately, liquids with higher electrical conductivities can be sprayed easily using electrostatic deposition. We demonstrated that a plant nutrient solution increases the conductivity sufficiently to produce an acceptable spray. But we needed to remove the electrical charge from the delivered nutrient solution droplets to prevent damage to the plants. By separating the current from the nutrient water flux, staticaponics proved to have a higher water use efficiency than traditional hydroponic or aeroponic growing techniques.