I've seen a number of similar project and, without exception, they all fail
if they attempt to do something new.
I'd strongly advise you to find groups who are already working on these problems and have built up deep knowledge about the issues which are faced.
There's no point going "I'm going to build an app to cure HIV!" if you haven't spoken to all the charities, health groups, and people who are already deeply immersed in this space. They already know which approaches won't work, which organisations have the best networks for promoting solutions, and who to go to for more advice.
So, my advice is don't brainstorm with engineers. Go out in to your community and find people who have an existing need which isn't being met.
Good luck!