A U.S. patent application listing Haile as an inventor was filed for a proton conducting membrane using a solid acid.
On November 15, 1999, Sossina M. Haile's work in materials science took a crucial leap forward with the filing of a U.S. patent application (No. 09/439,377) for a solid acid proton-conducting membrane. This innovation was pivotal in solid acid fuel cell technology, a field in which Haile would later pioneer groundbreaking advancements.
The patent application was a testimony to her innovative thinking and unmatched scientific curiosity. It demonstrated her ability to translate complex scientific concepts into practical technological advancements. The application's filing was a key moment in the commercialization and broader application of fuel cell technologies.