Device (106) for controlling the
voltage-dependent resistance, comprising: at least two electrodes (202, 204) at closely spaced endpoints; a first layer (210) applied to the at least two electrodes (202, 204), wherein the first layer consists of a
metal oxide; a second layer (208) applied to the first layer (210), wherein the second layer (208) consists of an
electrically conductive metal oxide; a forming contact (206) applied to the second layer (208), wherein a combination of the forming contact (206), the first layer (210) and the second layer (208) functionally connects the at least two electrodes (202, 204) to each other; and a computer
system functionally connected to the educational contact, wherein the computer
system (102) is designed to apply a predetermined
voltage to the first layer (210) and to the second layer (208) respectively, and to display an increase in the
total resistance using a
user interface.