There's a certain disconnected feeling that comes with using a touchscreen, and Sony isn't content with vibration being the sole standard for haptic feedback. The company has filed a bunch of patent applications for a stylus which instead uses artificially generated friction to make it harder or easier to move across the screen. It works using a "rolling contact ball gripping mechanism," which responds to instructions from the phone or tablet and employs actuators to increase or decrease friction on the roller ball tip. The various filings outline some potential benefits of this stylus-based haptic feedback, including being able to feel yourself "carving and molding" 3D objects in a design application, or understanding your character is "fatigued or damaged" while playing a game. We know that Samsung increased the friction of the Note II's S-Pen to make it feel more like writing on paper, but Sony's approach would potentially bring a whole new layer of interaction.