Peeling Back the Layers

As technology continues to evolve, so do the ways that we interact with our digital devices. Traditional interfaces have been the norm for decades, but more specialized and unique user interfaces are emerging as the next big thing.

Nontraditional user interfaces do not rely on frequently used input methods like a keyboard, mouse, or touchscreen. Instead, they use technologies such as voice recognition, gesture recognition, and eye tracking to allow users to interact with their devices in new and exciting ways.

Human-computer interaction is a very active area of research, with novel technologies being introduced by the day. Some of these technologies immediately seem very intuitive, and as though they are a natural extension of existing interface designs. At the other end of the spectrum, the interfaces are a bit more exotic, and may take some getting used to — if they ever see the light of day outside of a research lab, that is.

We will leave it up to the reader to decide exactly where along that spectrum this recently published user interface lies. Researchers at MIT CSAIL have developed what they call a computational composite material that combines computational power, sensing, actuation, and energy storage in a single, thin sheet. These sheets can be folded up into various shapes to produce digital objects that a user can tangibly interact with.

Each sheet, called a CompuMat, is composed of between three and five stacked layers. The essential three layers consist of a flexible printed circuit board (and any associated chips and other components) to provide the device with intelligence, an energy source, in the form of a 0.4 mm thick flexible lithium polymer battery, and a reprogrammable magnetic grid that allows portions of the sheet to attract or repel other specific areas of the CompuMat. Depending on the application, a support layer (e.g. cardboard, wood, steel) can be added to give the sheet additional structural strength. Finally, a top layer of fabric, acrylic, or other material can be added purely for aesthetic reasons, if desired.

Perhaps the most interesting layer is the magnetic grid, based on the Mixels user interface previously developed in part by members of this research team, that gives CompuMat unique interactive capabilities. Mixels are a grid of programmable, magnetic pixels that can individually be assigned a value of either 'north', 'south', or 'demagnetized'. Mixels can be programmed to make the sheet fold up in a specific way, or they can be leveraged to only allow certain other sheets with the proper, corresponding magnetic pattern to bind to a region.

The team created several demonstrations to show what CompuMat-based interfaces might look like in practice. In one example, a sheet was created that could recognize two different magnetic patterns. Two additional sheets acting as authentication keys were created with complementary magnetic patterns. An LED on the sheet would light up indicating which of the two users the attached key belonged to.

In another demonstration, a sheet of the computational composite material was folded up into a cube, and objects were placed inside, hidden from view. A code corresponding to the contents of the box was magnetically encoded in one of its sides, which allows external devices to determine the contents of the box without opening it by reading the code.

While these applications are interesting, none of them appear to be a killer app for CompuMat. There are simpler, and less expensive, ways to accomplish each of these tasks with existing technologies. Perhaps the perfect application for CompuMat will be discovered one day, but at present, it looks like it might be a solution in search of a problem.