With the little that I've learnt about aeroplanes, I know that the aileron is the control surface that a pilot use to roll the plane by decreasing the lift of one wing and increasing the lift of the other wing. And it's (aileron) generally located at the wing trailing edge.
Now, if the wing tip is made flexible (or hinged to the wing), can the wing tip serve the purpose of an aileron by lifting the wing tip upward or downward?