Bio-Inspired Micro/Nanostructures for Skin-Like Soft Sensors

Skin-like soft sensors with high sensitivities have gained great attention in the fields of human-machine interfaces, robotic skins, and healthcare applications. Although various types of wearable soft sensors based on novel materials and sensing mechanisms have been introduced, there remain challenges in their practical applications. To address these challenges, we draw inspiration from biological systems, which have evolved unique micro/nanostructures with excellent sensory capabilities and functions through continued adaptation to environmental changes. Inspired by the structure and function of biological systems, we present several structural design strategies for micro/nanostructured polymer composites as soft sensors with excellent sensing capabilities and their applications in wearable devices and human-machine interfaces. First, inspired by the fingertip skin structure and function, we develop multifunctional electronic skins capable of differentiating various mechanical stimuli (normal, shear, stretching, bending), static and dynamic pressure, and temperature with high sensitivities. Second, inspired by the sound frequency tunability of the cochlea, we demonstrate frequency-selective acoustic and haptic sensors for dual-mode human–machine interfaces (HMIs) based on triboelectric sensors with hierarchical ferroelectric composites. Finally, mimicking stimuli-responsive color changing structures found in biological systems, we present colorimetric tactile sensors that can monitor external forces based on the color change signals.