Most developers attempt to make haptic feedback universal in the same way as a speaker or display. Those can output any content fed to them, so they’re useful for a wide range of applications. Achieving that in a haptic interface has proven to be a big challenge, because it requires complex actuation. But what if that weren’t a constraint and each haptic device could accommodate a narrower focus? A team of Carnegie Mellon University engineers answered that question with Parametric Haptics.

Unlike the complex “universal” haptic devices that we normally see, each device in the Parametric Haptics collection suits only a small subset of possible tactile sensations. The device that simulates the feeling of dog’s fur, for example, is distinct from the device that simulates tree bark. However, similar textures, like dog’s fur and shaggy carpet, might share the same device.

Because every device has a dedicated purpose, the Parametric Haptics system only needs a single actuator. That straps onto the user’s arm to push and pull the attached device across the user’s skin. A small DC gear motor, controlled by an Arduino Nano board through a DRV8833 driver, moves the device. New devices are configurable in software according to input parameters, then 3D-printable.

The advantages of Parametric Haptics are simplicity, cost, and a very purposeful tactile experience. The disadvantage is the lack of versatility, because it can only produce one sensation at a time. To feel a new sensation, the user would have to swap out devices. Read more about the project in the team’s paper here.