Gates and others pumped $35 million into Berlin-based ResearchGate, which was started five years ago by three friends intent on making it easier for researchers to collaborate and share information.
"Our goal is to free knowledge from the ivory tower, to digitalize it and make it accessible for everyone in order to accelerate scientific progress," said ResearchGate co-founder and chief Ijad Madisch.
"We're excited to add to our group of investors whose goals are perfectly in line with ours, and who understand the relevance of what we are doing – not only for science, but for society."
The roster of ResearchGate investors includes Founders Fund and Benchmark in Silicon Valley.
Madisch, a virologist and computer scientist, was working on research in Boston when he was vexed by the likelihood that others had wasted money and time doing the same failed experiments that he was trying.
"I was very frustrated with the fact that science is broken," Madisch said. "My primary goal is to facilitate breakthroughs by connecting the right people with each other."
People must have email addresses at scientific institutions to join ResearchGate, which has grown to about 2.9 million members in 193 countries, the top being Germany, India, Britain, and the United States.
"Just as I witnessed at LinkedIn and Facebook, a true network-effect business like ResearchGate has the power to change the world," said Benchmark general partner Matt Cohler, who is on the ResearchGate board.
"We are just beginning to see the transformative impact of removing the arcane barriers to scientific collaboration and sharing."
Triumphs in the online community include a Nigerian scientist seeking the cause of a girl's death in Africa sharing data with a professor in Italy who then discovered that a dangerous yeast had mutated from plants to humans.
"This would not have been possible if they had not connected on ResearchGate," Madisch said after recounting the story.
"We have many more examples; in green chemistry, cancer research, engineering..."
This third round of funding will enable ResearchGate to beef up its platform for publishing results and to build software tools for members, according to Madisch.
ResearchGate is looking into the potential to make money with job boards where companies or schools can recruit talent, and with advertising focused on equipment needed for experiments.
Data at ResearchGate was to remain free and open. "I call it open science," Madisch said. "This will benefit all of us."