A Reversible, Versatile Skin-Attached Haptic Interface Platform with Bioinspired Interconnection Architectures Capable of Resisting Sweat and Vibration

Abstract

A stable conformal interface technology for rough and sweaty complex skin is essential for a haptic interface capable of delivering sophisticated mechanical stimuli. However, conventional polymeric/hydrogel-based skin adhesives cannot maintain adequate adhesion interaction performance at the haptic interface due to repetitive vibrations or sweaty skin. This study reports a reversible, versatile skin-attached haptic interface platform, which embeds the hybrid architecture of a water-drainable hexagonal array of frog toe pads and the energy-dissipation matrix of snail pedal muscles with interconnected structures. The hybrid frog-snail-inspired adhesive patch exhibits remarkable adhesion in pulling and shear directions under both dry and sweaty conditions. Furthermore, the microchannels between the hexagonal array can effectively drain liquid under sweaty conditions while also enhancing skin-conformal contacts. The adhesion force enhanced by energy-dissipation is analyzed considering a simple theory based on the adhesion, elastic, dissipation energies, and geometric features, resulting in the vibration-resistant characteristics against diverse dry and wet vibration environments (vibrational frequency: 1-150 Hz). Bioinspired integrated skin-attached haptic interface platform demonstrates the versatility of being reversibly applicable to various skin surfaces such as fingers, arms, and legs, yielding the feasibility of dynamic handling a basketball with multiple contacts and impacts in virtual reality (VR). The vibration- and sweat-tolerant adhesive patches for skin-attached haptic interfaces based on microstructural synergistic mechanisms are presented. To elucidate the robust adhesion mechanism, a hybrid bioinspired architecture analyzed in terms of capillary interactions and energy dissipation is proposed. Applications for implementing virtual reality space by integrating a bioinspired haptic interface platform into a vibrohaptic feedback system are successfully demonstrated.image