Haptics, or the feel of touch, is present in many of our technological devices such as cell phones, gaming devices, and virtual reality interfaces. Wearable gadgets rely heavily on haptic feedback, such as vibrations in smartwatches, to communicate information [1-2]. Recently, metasurfaces have been introduced as a versatile haptic interface to communicate information through the skin, with minimal usage of actuators and controls [3].&nbsp; These metasurfaces are ordinary flexible sheets (e.g., polycarbonate) that are decorated with a repeating geometric pattern in space (i.e., a unit cell) [4-7]. The main function of these unit cells or “pixels” is to amplify the input force, displacement or both in a localized manner based on resonance modes. Each of these pixels can encode different deformation patterns or mode shapes that are capable of producing complex tactile sensations on the human skin upon contact. For example, a harmonic signal containing multiple frequencies can be translated into a complex pre-programmed deformation pattern that can give a unique tactile sensation when it interacts with the skin. However, due to the varying curvature of the human body, such as the arm, identical geometric patterns might have different dynamical responses as a function of local curvature. In this work, we investigate the effect of curvature on the performance of metasurfaces. In addition, we utilize the large deformations leading to varying degrees of curvature as means to tune the response of these metasurfaces. We envision these metasurfaces as a versatile interface for applications in sound and vibration control as well as haptics.&nbsp;[1] Anikeeva, Polina, and Ryan A. Koppes. "Restoring the sense of touch."&nbsp;Science&nbsp;350, no. 6258 (2015): 274-275.&nbsp;[2] Yu, Xinge, Zhaoqian Xie, Yang Yu, Jungyup Lee, Abraham Vazquez-Guardado, Haiwen Luan, Jasper Ruban et al. "Skin-integrated wireless haptic interfaces for virtual and augmented reality."&nbsp;Nature&nbsp;575, no. 7783 (2019): 473-479.&nbsp;[3]&nbsp;Bilal, Osama R., Vincenzo Costanza, Ali Israr, Antonio Palermo, Paolo Celli, Frances Lau, and Chiara Daraio. "A Flexible Spiraling Metasurface as a Versatile Haptic Interface."&nbsp;Advanced Materials Technologies&nbsp;5, no. 8 (2020): 2000181.&nbsp;[4] Bilal, Osama R., André Foehr, and Chiara Daraio. "Bistable metamaterial for switching and cascading elastic vibrations."&nbsp;Proceedings of the National Academy of Sciences&nbsp;114, no. 18 (2017): 4603-4606.&nbsp;[5] Bilal, Osama R., André Foehr, and Chiara Daraio. "Reprogrammable phononic metasurfaces."&nbsp;Advanced materials&nbsp;29, no. 39 (2017): 1700628.&nbsp;[6] Foehr, André, Osama R. Bilal, Sebastian D. Huber, and Chiara Daraio. "Spiral-based phononic plates: From wave beaming to topological insulators." Physical review letters 120, no. 20 (2018): 205501.&nbsp;[7] Bilal, Osama R., André Foehr, and Chiara Daraio. "Enhancement of deep-subwavelength band gaps in flat spiral-based phononic metasurfaces using the trampoline phenomena."&nbsp;Journal of applied mechanics, Jul 2020, 87(7): 071009&nbsp;(2020).

Metasurfaces as a Generic Interface to Communicate Information Through the Skin

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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