I think what my supervisor concern is the price as well.
B.T.W, after studying the http://www.mcmanis.com/chuck/rob...-impl.html

I come up with the following circuit, i hope it might be better than the previous even though i think it is not correct.

And one more thing, the motor actaully is part of a printer , that is used to feed the paper. It needs only 0.19A, so my supervisor said using a clip for it is somehow wasted. And that can be easily to be implemented by using transistors and diodes.
And i am not a EE student, so my knowledge on transistors and circuit design, so sorry for taking your guys so much time on my stupid question...