ECE Seminar - Bio-Inspired Micro/Nanostructures for Skin-like Sensors

Abstract : Flexible electronic skin (e-skin) 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 e-skins based on novel materials, fabrication techniques,  and sensing mechanisms have been introduced, there are still challenges in their practical application. For example, e-skins for smart robots and prostheses should possess the ability to perceive and differentiate multidirectional forces such as normal, tensile, shear, and bending forces without crosstalk. Nature can offer alternative strategies for wearable e-skins to fulfill those requirements. Biological systems have evolved unique micro/nanostructures with excellent sensations and functions through continued adaptation to environmental changes. Inspired by the structure and function of biological systems, we show several structural design strategies of micro/nanostructured polymer composites for soft and flexible 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 demonstrate multifunctional electronic skins differentiating various mechanical stimuli (normal, shear, stretching, bending), static and dynamic pressure, vibration, acoustic sound, and temperature with high sensitivities. Second, inspired by the sound frequency tunability of the inner structure of 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 the mechanism of astringency perception on the human tongue, we demonstrate a soft and ion-conducting hydrogel artificial tongue for astringency perception.