You've probably seen TV shows in which groups of characters – usually forensic investigators – view data on large transparent touchscreen displays. Well, researchers at the Korea Advanced Institute of Science and Technology (KAIST) have taken that concept a step further. Their TransWall is not only transparent, but it can also receive input and display content on either side of its screen, plus it's capable of haptic feedback.
The system is housed within a T-shaped frame that also incorporates two overhead-mounted projectors, which project visuals onto either side of the screen. That screen is made up of two sheets of plexiglass, with a clear holographic film sandwiched between them. Bordering those sheets are two rectangular infra-red touch sensor frames, one on either side. A surface transducer is also mounted in the plexiglass above the frames, plus microphones are integrated into each of them.
When users on either side touch the plexiglass, the location and movements of their fingertip are detected by the frame on that side. That information is sent to a computer, which accordingly alters the images being projected onto that face of the holographic film. This means that users can draw lines, flip pages, select objects, and perform all the usual touchscreen functions.
Both users see the same two-projector display, so content viewed on one side of the screen is also visible on the other.
Additionally, the transducer can cause the screen to vibrate on command. Among other things, this can be used to make users feel like they're touching fingers through the screen. In scenarios where the TransWall might be built into the wall between two rooms, the microphones would also let the users talk to one another.
Some of the possible applications of the technology are demonstrated in the following video.