3D Integrated Physicochemical-Sensing Electronic Skin

Abstract

The integration of physical and chemical signal sensing is of great significance to bridge the gap between electronic skin (e-skin) and natural skin. However, the existing method of integrating physical and chemical signal sensing units in two dimensions is not conducive to the development of e-skin in multifunctionality and miniaturization. Herein, a new three-dimensional (3D) integrated physicochemical-sensing e-skin (TDPSES) is developed by integrating a piezoresistive sensing unit, a biochemical signal sensing electrode, and a microfluidic system in a 3D superposition mode. For pressure sensing, TDPSES demonstrates an ultra-high sensitivity of 208.6 kPa⁻¹ in 0–15 kPa and excellent stability of 8000 cycles. For glucose sensing in sweat, TDPSES has a sensitivity of 3.925 µA mm⁻¹ and a detection limit of 29.1 µm. Meanwhile, TDPSES can not only continuously detect biological fluids, but also self-monitor its fluid-driving behavior, demonstrating its intelligent fluid-driving characteristics. Furthermore, TDPSES is applied to monitor a variety of physiological signals such as sweat, pulse, and voice, demonstrating its multifunctional sensing capabilities and application potential in health care. In conclusion, the implementation of TDPSES provides a new idea for constructing miniaturized and multifunctional e-skin, which helps to narrow the gap between e-skin and natural skin.