Regular array of microscopic structures on a substrate and devices incorporating same

A device comprising an array of structures on a substrate, wherein:

• said array of structures is formed from a first surface layer comprising a first material, and said substrate comprises a second material, said first surface layer being sufficiently thin that stress fields at the interface of said surface layer and said substrate caused formation of separated regions of said first material on said substrate wherein said first surface layer comprises separated regions forming at least two structures, said at least two structures being each about 2 atoms to about 10 atoms in height and being separated from each other by about 10 nm to about 50 nm, wherein the direction of alignment of said separated regions and/or the relative position of adjacent said separated regions has been influenced by directing at least one first particle beam onto said surface layer and at a respective acute angle thereto.