Using an array of miniaturized electroosmotic pumps, the current prototype devices offer 5 mm of displacement from a 5 mm stackup which is a significant improvement over previous technologies which required a lot more hardware than the displacement provided. When placed under a flexible screen, notifications and other user interactions like the keyboard can raise and lower as desired.
Each layer is processed by laser before assembly and the finished device is self-contained, needing only electrical connections. No need for a series of tubes carrying fluid to make it work. Interaction surfaces have been able to scale from 2-10 mm in diameter with the current work, but do appear to be fixed based on the video (below the break).
The unique device consists of a control box, wires, and some electrodes attached to different spots on the back of the hand and fingers. Carefully modulated electrical signals create tactile sensations on the front, despite originating from electrodes on the back. While this has clear applications for VR, the team thinks the concept could also have applications in rehabilitation, or prosthetics.