Today, many scientific breakthroughs are through interdisciplinary research. As an important foundation of science, physics has tremendous potential to help other branches of science to advance. To illustrate the power of physics in solving important problems in life science, I present here some of my research projects as example: (1) My pioneer work in developing MRI for cancer detection; (2) Development of electroporation for gene transfer technology; (3) Development of bio-photonic techniques to uncover cell signaling mechanisms in a single living cell. This work not only allowed us to gain new insight into the mechanism of cell regulation and cancer development, it also provided a powerful technology for drug discovery.