All polymers and plastics share one common characteristic: They are thermal insulators. The plastics’ inability to transport heat is likely to cause severe trouble in modern electronic devices that are built with continuously higher power density. In order to enhance the thermal conductivity of plastics, they can be filled with particles that inherently provide high thermal conductivity. In the K-Project PolyTherm, such composites were prepared using micro- and nano-scaled fillershe content of fillers varies along one dimension, e.g. the height. In such gradient composites, the heat can be transferred away from the heat source with high efficiency.