Really, thats a very good idea to add some wild bending effects! Dean Miller used 4 servos controlled by four foot pedals with continuous ratiometric hall effect sensors. The servos are used to "pull" the 4 middle chords of the guitar (A-D-G-B), providing therefore an effect as if the string was bended.
Dean made the body of the guitar from a scratch with his CNC!
Watch the following video - The result is pretty good!