SEATTLE — If you have an unorthodox, unproven idea that can prevent HIV infection or help protect against infectious diseases, one of the richest men in the world wants to hear from you.

The Bill & Melinda Gates Foundation has set aside $100 million to encourage innovation in global health research, offering grants to those with innovative ideas on four topics: Tuberculosis, HIV, infectious diseases, and drug resistance.

The foundation’s new Grand Challenges Explorations program plans to give $100,000 each to about 60 projects in the first round of what is expected to be a five-year program.

Proposal applications are short — only about two pages long — and preliminary data is not required for the applications due at the end of May. They’ll be accepted beginning March 31.

Of course, each applicant will need to be a scientist and have a lab in which to do the work, foundation officials said. But there won’t many more restrictions.

Foundation officials say it’s one of the most open-ended requests for proposals they’ve ever issued, but it fits well with the organization’s quest to be innovative.

“We push ourselves to be as creative as we can,” the foundation’s chief administrative officer to be, Martha Choe, said.