Surveying the students when they graduated, she found that the careers they were pursuing were richer than “a single one- or two-track, which is what they were on before,” she said.

Rob Clark, the provost and senior vice president for research at the University of Rochester, who served as Dr. Johnson’s senior associate dean at the Pratt School and then succeeded her as dean, described her as an inspirational leader. When she started, he said, the engineering school lagged the university as a whole in rankings and general stature. In addition to raising $250 million and tripling the school’s teaching and research space, he said, she fostered a culture in which faculty more often pursued grants as teams, rather than individually, and encouraged entrepreneurship.

“We had many more faculty engaged in start-up activity,” Dr. Clark said. “That grew greatly when she was there and continues at the institution since her departure.”

He added, “All of the things you would have said couldn’t have been done in that length of time, she got them done.”

Dr. Johnson was born in St. Louis and grew up in Denver. An avid athlete, she wanted to play lacrosse in high school, but her school did not have a girls’ team, so she practiced with the boys. As an undergraduate at Stanford, she majored in electrical engineering, played varsity field hockey and started a women’s lacrosse club team that later became a varsity team. She also got her master’s degree and doctorate from Stanford.

From 1985 to 1999, she was an assistant professor and then a full professor at the University of Colorado, Boulder, and from 1994 to 1998, she directed a National Science Foundation-supported research center at the University of Colorado and Colorado State University. During this period, she also started two companies. She holds 42 United States patents. Among other things, she invented a camera that can pick up cancerous or precancerous cells on a cervical smear and technology that for the first time allowed for high contrast and faithful color in 3-D films, contributing to movies like “Chicken Little” and “Avatar.”

From 2007 to 2009, she was the provost and senior vice president for academic affairs at Johns Hopkins University. In 2009, she was confirmed as under secretary of energy, overseeing a $10.5 billion program that included nuclear energy, fossil fuels, renewable energy and waste management. She stepped down at the end of 2010 and started a company that builds and modernizes hydroelectric plants.