I think the best thing you can do is to go to the PMI website and read thoroughly the information provided about the certification process.
There you will certainly find answers to your query, regarding your particular case.
But one of the main prerequisites is in your case is that you must have acquired 36 months of project management experience (leading projects) within the last 8 years.
You can look at
www.pmi.org/certifications/process and
www.pmi.org/certifications/types/project-management-pmp.
Hi. I am a PhD (Mechanical Engineering), with 4 years of experience working at universities as researcher and 1.5 year experience in industry in R&D. I am wondering if these can cover that 3 year project management criterion? And if yes, how I can mention them in my application to justify that part? Thanks a lot for the help in advance.
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®