UNIVERSITY OF HOUSTON, 2017-Present
Distinguished Professor of Biomedical Engineering

UNIVERSITY OF CALIFORNIA, RIVERSIDE 2004-2016
Chairman, Department of Bioengineering
Distinguished Professor of Bioengineering

NASA-AMES RESEARCH CENTER 2001-2002
Division of Fundamental Biology

UNIVERSITY OF PITTSBURGH 1987-2003
Chairman, Department of Bioengineering (1998-2002)
Director, Center for Bioengineering and Biotechnology
Distinguished Service Professor of Engineering
Professor of Bioengineering
Professor of Chemical Engineering
Professor of Medicine

NATIONAL SCIENCE FOUNDATION 1985-1987
Deputy Director, Division of Cross‑Disciplinary Research
Section Head, Emerging Engineering Systems

UNIVERSITY OF MARYLAND/NIST 1984
Director of Development, Center for Advanced Research in Biotechnology

UNIVERSITY OF MICHIGAN 1964-1987
Chairman, Department of Chemical Engineering
Professor of Chemical Engineering

Sabbatical leave – Univ. North Carolina, Chapel Hill. 1983

Guest Prof. of Physiology (Univ. of Nijmegen, Holland), 1971‑1972
Sabbatical leave in the Department of Physiology, University of Nijmegen, Holland. D

LEDERLE LABORATORIES 1958-1964
Group Leader, Biochemical Research
Research and Development Engineer