Abstract: A three-dimensionally printed structure is provided. The three-dimensionally printed structure includes a first layer composed at least in part of a first material; a second layer composed at least in part of the first material, the second layer being positioned over, under, or through the first layer and having an interface with the first layer; and a first internal structure composed at least in part of a second material different from the first material, the first internal structure being situated in both the first layer and the second layer.