Tribute in honor of Prof. Ivo Alexander Hümmelgen, a member of the Brazilian materials research community, who died unexpectedly in March 2019. The tribute was made by Prof. Marco Cremona (PUC-Rio), on September 23, 2019 in Balneário Camboriú (Brazil), at the opening of symposium F, that was dedicated to Organic Electronics, the research area of Prof. Hümmelgen.