Battery‐Free and Wireless Epidermal Electrochemical System with All‐Printed Stretchable Electrode Array for Multiplexed In Situ Sweat Analysis

Abstract

Skin‐interfaced electrochemical sensing devices are widely developed for biochemical sensing at molecular levels. However, the sensing electrodes fabricated with photolithography or printing technique are hard to achieve high stretchability without special designs like serpentine shape. Also, most of them require wired connections with external electrochemical workstations for data acquisition or on‐board batteries to power the circuits, which largely restrain the flexibility, simplification, and miniaturization of the devices. Here, a battery‐free, wireless, and epidermal electrochemical system is presented for in situ biochemical sensing. The sensing component of the system is a stretchable electrode array all‐printed with soft polymer and conductive silver nanowires. The electrodes show stable electrical properties within strain range of 0–50%, without serpentine designs. The electronic component of the system is a fully integrated flexible circuit board with near field communication module, which enables wireless energy harvesting and data transmission with smartphones. The system demonstrates good performance in real‐time on‐body sweat analysis for simultaneous quantitative detections of glucose, hydrogen, sodium, and potassium. This battery‐free and wireless epidermal electrochemical system provides a simplified, miniaturized, and flexible solution for a wide range of biochemical platforms, including wearable and implanted bioelectronics.

Advanced Soft Materials, Sensor Integrations, and Applications of Wearable Flexible Hybrid Electronics in Healthcare, Energy, and Environment

“…This offers the possibility of a stable adhesion at the various surfaces and interfaces of WFHE by blocking the water that comes from breathing, sweating, washing, and showering. [6,54,69,235,236] Moreover, an antifreezing effect induced by superhydrophobicity foresees the use of hydrogel-based WFHE in an extremely cold environment under 0 °C. [206,210] In this section, we introduce some recent methods to change the water affinity of wearable substrates, along with emerging materials that contribute to the enhancement of the water repellency.…”

Integrated textile sensor patch for real-time and multiplex sweat analysis

“…Comparison of the sensitivity for various biomarkers of the recently reported wearable electrochemical sensors for sweat analysis with this work. References (41)(42)(43)(44)(45)(46)(47)(48)…”

The review of Lab‐on‐PCB for biomedical application

“…Especially in the last 2 years, it has received great attention. According to different detection methods and analysis principles, these biomedical applications can be divided into four categories: (1) cell analysis based on Coulter's counting principle and cell imaging technology for analysis of red cells, white cells, and tumor cells [10][11][12][13][14][15][16]; (2) biochemical analysis based on various enzyme reactions for analysis of blood glucose, electrolytes, and other nutrients in the human body [17][18][19][20];…”