In 1966, he was awarded a Fulbright Scholarship to study in the US. He spent a year at the University of Wisconsin–Madison, and earned a master's degree in biophysics. While at the Charles Stevens Laboratory at Yale University for post-doctoral work he met fellow scientist Eva-Maria Neher, whom he married in 1978 and subsequently the couple had five children – Richard, Benjamin, Carola, Sigmund, and Margret.