Using Spatiotemporal Modulation to Draw Tactile Patterns in Mid-Air
- 1.5k Downloads
One way to create mid-air haptics is to use an ultrasonic phased-array, whose elements may be controlled to focus acoustic pressure to points in space (referred to as focal points). At these focal points the pressure can then deflect off the skin and induce a tactile sensation. Furthermore, by rapidly and repeatedly updating the position of a focal point over a given trajectory, ultrasound phased-array can draw two dimensional curves (referred to as patterns) on a users’ palms. While producing these patterns, there are three major parameters at play: the rate at which the pattern is repeated, the pattern length, and the focal point speed. Due to the interdependence between these parameters, only the repetition rate (frequency) or the speed can be set for a tactile pattern of a given length. In the current study, we investigate which approach (frequency or speed) is most effective at maximising the tactile sensation. We first carried out a vibrometry study to show that optimising the speed can maximise the skin deflection caused by a focal point following circular patterns. A further user study was undertaken to show that optimising the speed consequently maximises the perceived intensity of the tactile pattern. In both studies, the optimal speed result is shown to be equivalent to the speed at which surface waves propagate from the skin deflection effected by the focal point. Overall, our investigations highlight the importance of the speed of stimulation movement in the design of tactile patterns.
KeywordsTactile Pattern Spatiotemporal Modulation Ultrasound Phased Array Surface Wave Propagation Circle Circumference
The authors would like to thank the Directors of Ultrahaptics for their support. This research has received funding from the European Union’s Horizon 2020 programme No. 638605 and No. 737087.
- 1.Carter, T., Seah, S.A., Long, B., Drinkwater, B., Subramanian, S.: UltraHaptics: Multi-Point Mid-Air Haptic Feedback for Touch Surfaces (2013)Google Scholar
- 2.Delhaye, B., Hayward, V., Lefèvre, P., Thonnard, J.L.: Texture-induced vibrations in the forearm during tactile exploration. Front. Behav. Neurosci. 6(July), 37 (2012)Google Scholar
- 5.Ito, M., Wakuda, D., Inoue, S., Makino, Y., Shinoda, H.: High spatial resolution midair tactile display using 70 kHz ultrasound. In: Bello, F., Kajimoto, H., Visell, Y. (eds.) EuroHaptics 2016. LNCS, vol. 9774, pp. 57–67. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-42321-0_6CrossRefGoogle Scholar
- 10.Komandur, S., Johnson, P.W., Storch, R.L., Yost, M.G.: Relation between index finger width and hand width anthropometric measures. In: Proceedings of the 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society: Engineering the Future of Biomedicine, EMBC 2009, pp. 823–826 (2009)Google Scholar
- 11.Krylov, V.V., Dawson, A.R., Heelis, M.E., Collop, A.C.: Rail movement and ground waves caused by high-speed trains approaching track-soil critical velocities. Proc. Inst. Mech. Eng. Part F: J. Rail Rapid Transit 214(2), 107–116 (2000)Google Scholar
- 13.Long, B., Seah, S.A., Carter, T., Subramanian, S.: Rendering volumetric haptic shapes in mid-air using ultrasound. ACM Trans. Graph. 33(6), 181:1–181:10 (2014)Google Scholar
- 16.Obrist, M., Seah, S.A., Subramanian, S.: Talking about tactile experiences. In: Proceedings of CHI 2013, pp. 1659–1668. ACM, New York (2013)Google Scholar
- 19.Sodhi, R., Poupyrev, I., Glisson, M., Israr, A.: AIREAL: interactive tactile experiences in free air. In: SIGGRAPH (2013)Google Scholar
- 20.Tsalamlal, M.Y., Issartel, P., Ouarti, N., Ammi, M.: HAIR: HAptic feedback with a mobile AIR jet. In: Proceedings - IEEE International Conference on Robotics and Automation, pp. 2699–2706 (2014)Google Scholar