After graduating Stanford in 2009, Buie began teaching at Massachusetts Institute of Technology (MIT) in 2010.During his teaching career, Buie had also worked on numerous of research labs. In 2010, he worked on microbial fuel cells at UC Berkley. In 2012, he was working alongside a team in Australia to test the effectiveness of bacteria in these microbial fuel cells.Buie is the Esther and Harold E. Edgerton Career Development Professor of mechanical engineering at MIT, and leads the Laboratory for Energy and Microsystems Innovation (LEMI).
Cullen Buie is a co-founder of a startup called Kytopen, which has created a technology called Flowfect. This new technology gives scientists a way to mass-produce genetically engineered cells as it opens the pores of cells to deliver genetic material.