mplatcs

I am looking for a summer internship opportunity as a PhD student at one of the top universities such as MIT, Stanford, Caltech etc. Actually, I could not find any webpage which mentions such opportunities.

Do you know whether there are such opportunities?

RacinReaver

Your best bet would be trying to network your way to a joint project between your current advisor and a professor at another school you'd like to work at.

PhD level projects generally take a bit of time to get going, and every lab has its own learning curve, some three months somewhere really isn't enough time to get serious research done unless you're just trying to learn a new technique or make a ton of samples to use back at your home school.