Devices and methods are provided. In one aspect, a device for driving a memristor array includes a substrate including a well having a bottom layer, a first wall and a second wall. The substrate is formed of a strained layer of a first semiconductor material. A vertical JFET is formed in the well. The vertical JFET includes a vertical gate region formed in a middle portion of the well with a gate region height less than a depth of the well. A channel region is formed of an epitaxial layer of a second semiconductor wrapped around the vertical gate region. Vertical source regions are formed on both sides of a first end of the vertical gate region, and vertical drain regions are formed on both sides of a second end of the vertical gate region.