Whilst I appreciate the sincerity of your proposed endeavour, all I can see in your plan are the pitfalls.
Yes the knee has a bone near the skin surface like the scalp, but there the similarity ends.
The skin on my knees is loose and wrinkles, unlike my scalp.
I have never known the front of my knee perspire, unlike my scalp.
My scalp is oily, my knees are dry.
My knee bends, my scalp doesn't.
Do you plan to apply hair wax, hairspray or gels to the 1 inch square of hair on your knee?

All this will & does affect the bond.

And like Matt said, we really need to know if you'll be wearing shorts or long trousers because the rubbing of the trouser leg on your knees will have to be taken in to serious consideration when interpreting your findings.
You could of course wear satin trousers and thus emulate the same friction one might get from a satin pillow case and this would be a more like-for-like study.