An energy harvesting device for obtaining instantaneous energy from drops without needing of moving the drops along the device, in a reduced scale and combinable with other types of harvesting devices, the energy harvesting device comprising one or more triboelectric generators comprising a bottom electrode, a friction or triboelectric element placed over the bottom electrode, and at least two top exposed electrodes electrically connected placed over the triboelectric element and defining at least one gap between them, exposing the triboelectric element to the external environment so that on contacting a drop of liquid makes an electrical connection between the top electrodes varying instantaneously (microseconds range) the capacitance of the triboelectric generators.s