A memory device including a stack of layers. At least one first active layer is based on a crystalline ionic and electronic conducting material capable of releasing and/or accepting at least one ionic species. At least one second active layer is based on a crystalline ionic and electronic conducting material capable of releasing and/or accepting the ionic species. The first active layer and the second active layer are based on a material that has a high potential variation for a low variation in the concentration of the ionic species. At least one layer forms an electrolyte between the first active layer and the second active layer, and is based on at least one ionic conducting and electronic insulating material. A measurement instrument is provided for measuring the electrochemical potential difference between the first active layer and the second active layer.