amplifying voltage produced by muscle movements

[black_wing]

can anyone help me...
does any one knows how to make a circuit that can amplify the voltage produced by the movements of our muscles that is easy to make and is low cost, so that if I connect it to a transistor switch or other switching devices, it can triger somethig to move...

if you know any websites that can tell me more about it.

thank you verymuch...