One thing to look at here is Small Business Innovation Research grants. I know a lot of companies who exist just to do SBIRs and trying to productize other SBIRs.SBIRs are also a lot of fun, tend to be more research focused, and often you can get a decent amount as part of the grant.
Varies by dept to dept but some of the phase 1 grants can be up to a quarter or a half million dollars.
They’re grants, too. If your research flops, you’re not on the hook for it.
If you make it to phase three, congratulations! You’re now a supplier of a government procurement contract, and the government paid for your entire R&D effort, plus your salaries along the way.