Researchers at Microsoft have built a pair of experimental methods of haptic feedback for virtual reality controllers. The researchers' NormalTouch and TextureTouch are novel ways of allowing users to experience the sense of touch in a more satisfying manner than video game-style rumble feedback.
NormalTouch uses a "tiltable and extrudable platform" to provide force feedback to users' hands. The demonstration of the system in the Youtube video shows the device automatically making adjustments for uneven hand motion, too. Meanwhile, TextureTouch uses a 4x4 grid of extrudable pins that move up and down relative to the user's finger to mimic the shape of 3D objects in the virtual space. The researchers claim that TextureTouch can reproduce certain surface textures of virtual objects in addition to providing haptic feedback regarding their shape.
Both controllers are tracked using an OptiTrack tracking system and let users sense and interact with virtual objects. The researchers say both devices have the potential to improve VR interaction when compared to systems that provide only visual feedback or a combination of visual and vibration-based feedback. The devices are in the research phase, so products based on these technologies are probably a while off in the future. The research paper mentioned in the video can be found here.