Simmons joined the University of Toronto in 2005, and is joint-appointed in the Department of Mechanical & Industrial Engineering and the Institute of Biomaterials and Biomedical Engineering, and cross-appointed to the Faculty of Dentistry.
He is the Distinguished Professor of Mechanobiology, and has been the recipient of the McCharles Prize for Early Career Research Distinction (2010), the McLean Award (2012), the Faculty Teaching Award (2016), and the Northrup Frye Award (2017). In 2014, he became a Fellow of the Canadian Society for Mechanical Engineering.
Simmons has previously served as the Biomedical Option chair in the Division of Engineering Science and as associate director of research for the IBBME.
He is currently the scientific director of the Translational Biology & Engineering Program (TBEP) at the Ted Rogers Centre for Heart Research, and will continue to serve in the role throughout this transition period.