Ask HN: What are my options after master's degree?

Masters in Mech (vibrations to be specific). I work at one of the big 3's in Michigan (automobile). I have about 2.5 yrs of work experience (after masters). I earn somewhere between 80 and 85k per year. I have deep interest in computer aided applications in mechanical engg. Generally speaking, I am the first person (in my team) to come up with a VB script or MATLAB equivalent to solve signal processing problems. I pursued research based masters, hence most of it was funded. I want to further advance my career by pursuing more research (which I don't get to do at work) I am considering PhD, but I am not willing to go on full time PhD (because I am on H1B, and don't want to give away my hard-earned[read as lottery] VISA and pay). I am afraid, a part time PhD will take too long, and I am unsure about the direction in which it will lead me. I lack conventional computer science education, and do not want to jump the ship by simply becoming a programmer (and hence sacrificing the masters deg or vibrations expertise)

I am thrilled about multiple developments in tech, intel realsense, project tango, virtual reality, self driving cars and wide arrays of technologies. I feel an urge to develop something (just like i did during my masters research), while making sure it fulfills my desire, I also want it to help advance my career. (i am a nerd who wants to monetize on his tinkering projects, while staying away from entrepreneurship thing, because i like getting paid, and/or need to be paid for maintaining my VISA status) I am 26 and single, I am fairly occupied with work, hence I just have weekends and couple of hours everyday to pursue my new adventure.

What should I do? Please share your thoughts.