An electrical or electro-optical device (100) includes a first layer (110) having a first composition. The first composition includes a plurality of electrically connected particles. A second layer (130) has a second composition, the second composition including a plurality of electrically connected particles. A composite layer (120) is disposed between the first and second layer. The composite layer is an interpenetrated network of a third and a fourth composition, wherein the third composition is different from the fourth composition. A first electrically interconnected network extends from the first composition in the first layer (110) to the third composition throughout a thickness of the composite layer (120), and a second electrically interconnected network extends from the second composition in the second layer (130) to the fourth composition throughout the thickness of the composite layer.