Actuators are the moving part of a device that controls the mechanism of a system. A simple example of an actuator is the opening of a valve. With this simple example of a solenoidal valve, we can understand that an actuator (or, in other words, a part that performs a movement in a specific direction) needs a control signal along with the source of energy. The control signals are relatively low energy in the form of voltage or current. The control system can be software-based, a human, or any other input. Combining actuators with mixed reality applications can open up a whole new world of interaction. Mixed reality refers to combining real and virtual worlds for producing new environments and visualizations.
With mixed reality, physical and digital objects can co-exist and interact in real-time. A team of researchers from the University of Chicago recently published an article on a foldable haptic actuator for rendering touch in Mixed Reality. This device is developed to provide an interactive environment where the user can touch a virtual object. The device provides feedback to mixed reality (MR) environments by pressing against the user’s fingerpad when a user touches a virtual object. It provides low-frequency vibrations on the finger contact points. The device is called Touch&Fold, and it is designed to fit on a user’s fingernail. When the device is not in use (when the user is touching real-world objects), the device folds back on top of the user’s nail.
Touch&Fold features a linear resonant actuator that allows rendering not only touch contacts (i.e., pressure) but also textures (i.e., vibrations). The device is wireless and self-contained. It measures only 24×24×41 mm and weighs 9.5 g. The actuation takes only 92 milliseconds.
Many haptic devices on the market enable users to interact with objects in the virtual world, such as controllers and gloves, but none provides the ability to interact with objects in both worlds and feel them at the same time.
