Hearne spent 18 years as a scientist and manager at
Sandia National Laboratories in Albuquerque, New Mexico, where he rose to be the co-director of the Center for Integrated Nanotechnologies. In 2019, joined
Oak Ridge National Laboratory as the director of first the Center for Nanophase Materials Sciences and then the director of the Materials Science and Technology Division (MSTD). In 2022, Hearne became the President and CEO of the
Southeastern Universities Research Association (SURA). Hearne also sat on numerous boards and review committees including Princeton University's External Advisory Council for the Princeton Materials Institute and Georgia Tech's advisory board for SENIC, a National Science Foundation user facility. ==Research==