Three dimensional integration is considered as a very promising technology for integrated circuit design. However, the ensuing thermal issues have posed threat to further development of Three-dimensional integrated circuits (3-D ICs).Cooling 3-D ICs with thermal through silicon vias (TTSVs) is well known. In this work we utilize time dependent temperature fluctuation in active layers of 3D IC and convert it to electrical energy using pyroelectric effect. We propose novel TTSV structure modification so that TTSVs can be used for both on chip energy harvesting and heat mitigation. © 2014 IEEE.