Toni Zweifel (15 February 1938 â 24 November 1989) was a Swiss Catholic engineer who patented several inventions. He founded and served as director of the Limmat Foundation, a foundation that supports social projects all over the world with a majority of women as project beneficiaries. He was a numerary member of the Opus Dei. A beatification process for Zweifel has been opened, and he is therefore titled a Servant of God.