Simple Projects

I am a 2nd year mechanical engg. student. me and my friends were thinking about some small project that can be amazing but at same time affordable. we dont hav too many ideas since we just stepped into 3rd semester.we had thought of idea like magnetic suspension with just a permanent mag. & an electromag.,wheelchair working on recharge able cells along with solar panel,.....but i guess most of these were already patented..so are there projects that we can give it a try..but if possible get a patent?