The present invention relates generally to dendritic metal structures and devices including them. The present invention also relates particularly to methods for making dendritic metal structures without the use of solid electrolyte materials. In one aspect, a method for constructing a dendritic metal structure includes providing a substrate having a surface and a cathode disposed on the surface; providing an anode comprising a metal; and disposing a liquid on the surface of the substrate, such that the liquid is in electrical contact with the anode and the cathode; and then applying a bias voltage across the cathode and the anode sufficient to grow the dendritic metal structure extending from the cathode. The methods described herein can be used to grow dendritic metal electrodes, which can be useful in devices such as LEDs, touchscreens, solar cells and photodetectors.