Haptic Feedback That Gets on Your Nerves

Virtual worlds are becoming more realistic all the time. Rapid advances in display, audio, and body tracking technologies, in particular, are making the experiences more immersive than ever before. But these huge leaps forward are not being met with the same level of progress in technologies that can reproduce tactile sensations. And that is a big deal — if a user of a virtual reality headset reaches out and touches a virtual object only to feel nothing, the illusion will be broken.

This is not to say that haptic interfaces do not exist. Many such systems are available today. However, they typically rely on simple mechanisms, like basic vibration motors, to produce tactile sensations. These devices are very limited in the range of effects that they can produce, and they are not very convincing — especially when sensations like complex textures need to be reproduced.

A team led by researchers at the University College London believe that they have a better way to deliver tactile stimuli. They have developed what they call the Bioinspired Adaptable Multiplanar Haptic (BAMH) system, which is capable of recreating authentic-feeling touch experiences. That could make BAMH ideal for use in virtual reality, medicine, research, and more.

The new system leverages knowledge of the four primary types of touch receptors found in human skin to create a realistic experience. Some of these receptors are good at, for example, detecting the edges of objects, while others excel at recognizing textures. By providing multiple types of stimulation that targets these varied receptors at the same time, BAMH is able to simulate some very complex sensations.

The BAMH device is constructed from a soft, silicone-based material that is pneumatically actuated and designed to contact the fingertips. The electro-pneumatic control subsystem that drives the actuation can produce both static and vibratory forces at multiple locations on the fingertip. Fast-switching valves allow the vibrations to reach a maximum frequency of 280 Hz, which is sufficient to stimulate even the fastest acting types of human touch receptors.

In addition to some of the more obvious use cases, like virtual reality, the researchers also suggest that their device could be used to assist in diagnosing individuals that are losing their sense of touch. Typically, this is done via a labor-intensive procedure in which medical providers use single-fiber brushes with increasing sizes to determine where, and to what extent, the patient still has their sense of touch. But by using the BAMH system, this process could be entirely automated.

In the future, the team plans to continue refining their device. One of their goals is to increase the switching frequency of the actuators to 400 Hz. At that speed, it would be able to stimulate even more types of mechanoreceptors in the skin. They are also planning to work toward increasing the spatial resolution of the system so that it can produce more convincing sensations.