Whilst there may be some personal benefit in obtaining a PE (a lot of PEs seem to think that it is some step up, which given its 'tick the box, follow the rules' academic requirements seems a bit odd (I am less cynical about the strict 4 year EIT requirement, but that gets waived quite frequently now)), those three fields are exactly those where a PE is unnecessary. Companies in those areas tend to operate under the industry exemption - where stuff is not built to code for direct consumption by the public.
Oh, and unless your academic advisor has ever had a real job I wouldn't take his career advice too seriously, unless you intend to become an academic yourself.
Cheers
Greg Locock