Professor Chien's research on how blood flow regulates interaction between the blood stream, blood cells and artery walls also leads to new information relevant to other types of cells, e.g., stem cells and cancer cells. At the molecular level, he is discovering how mechanical forces signal gene expression to cause cell growth, migration and cell death. Chien takes a multidisciplinary, integrative approach that combines engineering and biomedical sciences. He employs an array of technologies including nanotechnology, DNA microarray, bioinformatics, cell biophysics and biomechanics in his research on the cardiovascular system.

Chien joined UCSD in 1988 and became the founding chair of the Department of Bioengineering in 1994. In 2008, Chien became the founding Director of UC San Diego's new Institute of Engineering in Medicine to foster collaborations among the faculty of UCSD and with research institutes and biomedical companies in San Diego. As principal investigator on the Whitaker Foundation Development Award (1993) and Leadership Award (1998), Chien played a major role in establishing UCSD's bioengineering program as one of the top programs in the country. As founding Director of the UC Systemwide Bioengineering Institute in California, he has contributed to collaborations in research and education among the ten UC campuses.