'Holographic' haptic discovery could lead to more realistic virtual displays
The study used high resolution optical imaging, simulations and perception experiments to study ultrasound-excited waves that are excited in the skin during haptic holography interactions. The researchers found that holographic displays excite widespread vibration patterns, shock waves, in the skin.
The shock waves are created when ultrasound waves are focused and scanned in mid-air, causing vibrations in the skin. These vibrations can interfere with each other in a way that amplifies their strength at certain places. This creates a trailing wake pattern that extends beyond the intended focal point, reducing the spatial precision and clarity of the tactile sensation.
Team members on the study believe that current holographic haptic displays excite shock wave patterns that are so spread out in the skin, that the sensations can feel spread out and diffused. To overcome this obstacle, new developments in acoustics are needed.
Yon Visel associate professor, College of Engineering, UCSB, commented: “Our study reveals how holographic haptic displays, which are a promising new technology for virtual reality and telepresence, require new knowledge in acoustics innovations in design.
“By understanding the underlying physics of ultrasound-generated shear shock waves in the skin, we hope to improve the design of haptic holographic displays and make them more realistic and immersive for users. Such haptic displays could enable us to augment our physical surroundings with a limitless variety of virtual objects, interactive animated characters, or graspable tools that can be not only seen, but also touched and felt with the hands.”