I've hired/mentored and worked with a ton of writers at varying experience levels. So, I have a note of caution - often, your results will be better if you optimize for research skills and the ability to write professionally. Subject matter experts often suck with deadlines and they're hellish to edit!!

That said, if I was looking for robotics/AI writers, I'd go to my local University and talk to the Computer Science/Software Engineering/Electrical Engineering student associations.

Good luck!