Complex sentence: Prior to assuming his position as director of NSF, Suresh served as MIT's Dean of Engineering from July 2007 and had held MIT faculty appointments in Materials Science and Engineering, Mechanical Engineering, Biological Engineering, and Health Sciences and Technology.
Split into simpler sentences: Prior to assuming his position as director of NSF, Suresh had been MIT's Dean of Engineering. Suresh began his tenure as dean in July 2007 and had held MIT faculty appointments in Materials Science and Engineering, Mechanical Engineering, Biological Engineering, and Health Sciences and Technology.