US Patent 9067811 System, method, and control for graphenoid desalination

A method is disclosed for deionizing water and purging ions. A first graphene sheet and a second graphene sheet are positioned between a water flow path input and output. A first electrical charge is applied to the first graphene sheet and a second electrical charge to the second graphene sheet, which causes the first graphene sheet to repel ions of the first electrical charge from transiting apertures in the first graphene sheet, influences ions of the second electrical charge from transiting the apertures in the first graphene sheet, and causes the second graphene sheet to repel ions of the second electrical charge from transiting the second apertures. Water is introduced into the water flow path input, through the first graphene sheet, and then through the second graphene sheet, resulting in deionized water at the output. A sensor monitors the capacitance of the graphene sheets to determine when purging is needed.