Greetings Everyone, 
 
I am a recent graduate currently working in industry as a shift engineer for a major computer component manufacturer.  I was strongly advised to obtain "real world" experience before obtaining an advanced degree by a family member, but lately I have been feeling... unchallenged by day-to-day work and am considering an attempt to return to grad school.  I am hoping that in graduate school and afterwards, I will have more opportunity to work on more advanced, in-depth problems, and fewer monotonous tasks than in my current position or one that I could gradually advance to with just a bachelor's degree. 
 
My background: 
1.  Started as biomedical engineer, completed degree requirements in 2009 
2.  Stayed extra year at same school to complete chemical engineering 2nd major, completed degree and graduated in 2010 in top 5 ChemE bachelor program. 
3.  Top grades in BME coursework, average grades in ChemE, overall tech GPA 3.59 
4.  2 summer REU's at a lab in Cornell, work focused on microfabrication, similar to current job (1 strong LOR) 
5.  Some bio lab work for a professor at home university (1 above average - strong (?) LOR for professor in BME program, did very well in his traditionally difficult class also) 
6.  Also, one summer REU at NIST, and an internship at a medical device manufacturer 
7.  Unfortunately, no publications as undergrad 
8.  Currently working since mid 2010 as shift engineer with semiconductor-type fabrication technology, such as photolith, vacuum etch and depositions, SEM, etc.  (Probably 1-2 strong industry LOR) 
 
Lately I have been considering returning to graduate school for a doctorate.  In my current position I feel that my skills as an engineer are underutilized, and I get few opportunities to apply engineering knowledge to solving problems.  My work now is focused on keeping parts moving through various processes in a factory.  I would like to have more opportunities to tackle larger problems that require more in-depth thought, and would prefer a job with fewer demands to take care of various day-to-day tasks that I do not find intellectually challenging. 
 
I am wondering: 
1.  Do I have any chance of being accepted into a decent ChemE or BME graduate program, after being out of school for a few years?  By the time I would be potentially entering grad school (Fall 2013), I would have been out 3 years. 
2.  Are there any particular programs that I would have a better chance of acceptance into, or is there anything I can do to bolster my chances? 
3.  Am I considering grad school for the right reasons?  Would I be better off just sticking with my job in industry, even if I don't find it super-fascinating, possibly just get a masters, and gradually climb to hopefully more interesting challenges?  What is the right reason to earn a PhD? 
4.  I would like to move back towards more biology-related work, and am also fascinated with BioMEMS.  Is this a good field to get into? 
 
Thanks everyone, any advice is greatly appreciated!