a design in mind help

I have an idea for a tat but can't draw at all. I want it done on the back of my leg where my calf is. I want it too look like my skin is torn apart and shows a robotic bone or something on that line. I saw a tat one time where it was a angel and her leg was torn to show she is really a robot. Any one can vision this and can send me a drawing would be great. Thank you jiggles