The apparatus 21 also comprises a gate electrode 43. In the example of FIG. 4 the gate electrode overlaps a portion of the layer of two dimensional material 23. In the example of FIG. 4 a portion of the gate electrode 43 extends across the discontinuity 29 underneath the middle portion 56 of the dielectric 35 and the middle portion 55 of the layer of two dimensional material 23. The portion of the gate electrode 43 which extends underneath the layer of two dimensional material 23 is indicated by the dashed line 57 in FIG. 4. The dielectric 35 may insulate the layer of the two dimensional material 23 and the gate electrode 43.

In the example of FIG. 4 at least part of the gate electrode 43 may be supported by the moldable polymer 27. The discontinuity 29 may have a U-shape so that the portion of the gate electrode 43 which is not overlapping with the layer of two dimensional material 23 is provided on the moldable polymer 27. The moldable polymer 27 may extend up to the edge of the layer of two dimensional material 23 to reduce bending forces on the gate electrode 43.