A device for electrically controlled transport of ions between a source and a target electrolyte, comprising: a first source electrode and a first target electrode, each capable of conducting ions and electrons, wherein said source electrode is arranged to receive ions from said source electrolyte and said target electrode is arranged to release ions to said target electrolyte, and means for retaining one of said source and target electrolytes on the device, which means are arranged such that each electrolyte is in contact with one of said electrodes, and a first ion-conductive channel, arranged to receive ions from said source electrode, to release ions to said target electrode and to provide an ionic connection between said source and said target electrodes, wherein said electrodes (101,104) and said ion-conductive channel are formed of solid or semi-solid materials which are directly or indirectly attached to a support, further comprising means for limiting an electronic current between said source and said target electrodes, such that at least after a voltage is applied across said channel a potential difference between said source and target electrodes is maintained, which effects ion transport from said source to said target electrode, and wherein the cross-sectional area of the interface between said ion-conductive channel and one of said electrodes (101;104) is within the range of about 1 nm 2 to about 10 mm 2, characterised in that the device further comprises: - at least one additional ion conductive channel (103b-d), - at least one additional ion conductive source electrode (102b-d), each comprising an ion passage surface, - means for retaining a source electrolyte in ionic contact with each of said at least one ion passage surface, wherein a first portion of each of said at least one additional ion conductive channel (103b-d) is arranged in ionic contact with said first ion conductive channel, and wherein a second portion of each of said at least one additional ion conductive channel (103b-d) is arranged in ionic contact with one of said at least one additional ion conductive source electrodes (102b-d), respectively, further comprising means for limiting an electronic current between said target electrode and each of said at least one additional source electrode (102b-d), such that at least after a voltage is applied across a respective one of said at least one additional ion conductive channel, a potential difference between a source and a target electrode is maintained, which effects ion transport from said source to said target electrode, and wherein said first ion conductive channel and said at least one additional ion conductive channel further comprise a common point of intersection. a first source electrode and a first target electrode, each capable of conducting ions and electrons, wherein said source electrode is arranged to receive ions from said source electrolyte and said target electrode is arranged to release ions to said target electrolyte, and means for retaining one of said source and target electrolytes on the device, which means are arranged such that each electrolyte is in contact with one of said electrodes, and a first ion-conductive channel, arranged to receive ions from said source electrode, to release ions to said target electrode and to provide an ionic connection between said source and said target electrodes, wherein said electrodes (101,104) and said ion-conductive channel are formed of solid or semi-solid materials which are directly or indirectly attached to a support, further comprising means for limiting an electronic current between said source and said target electrodes, such that at least after a voltage is applied across said channel a potential difference between said source and target electrodes is maintained, which effects ion transport from said source to said target electrode, and - at least one additional ion conductive channel (103b-d), - at least one additional ion conductive source electrode (102b-d), each comprising an ion passage surface, - means for retaining a source electrolyte in ionic contact with each of said at least one ion passage surface,