All‑Fiber Integrated Thermoelectrically Powered Physiological Monitoring Biosensor

Advanced fabric electronics for long-term personal physiological monitoring, with a self-sufficient energy source, high integrity, sensitivity, wearing comfort, and homogeneous components are urgently desired. Instead of assembling a self-powered biosensor, comprising a variety of materials with different levels of hardness, and supplementing with a booster or energy storage device, herein, an all-fiber integrated thermoelectrically powered physiological monitoring device (FPMD), is proposed and evaluated for production at an industrial scale. For the first time, an organic electrochemical transistor (OECT) biosensor is enabled by thermoelectric fabrics (TEFs) adaptively, sustainably and steadily without any additional accessories. Moreover, both the OECT and TEFs are constructed using a cotton/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/dimethylsulfoxide/(3-glycidyloxypropyl) trimethoxysilane (PDG) yarn, which is lightweight, robust (90° bending for 1000 cycles) and sweat-resistant (ΔR/R ₀ = 1.9%). A small temperature gradient (ΔT = 2.2 K) between the environment and the human body can drive the high-gain OECT (71.08 mS) with high fidelity, and a good signal to noise ratio. For practical applications, the on-body FPMD produced an enduring and steady output signal and demonstrated a linear monitoring region (sensitivity of 30.4 NCR (normalized current response)/dec, 10 nM ~ 50 µM) for glucose in artificial sweat with reliable performance regarding anti-interference and reproducibility. This device can be expanded to the monitoring of various biomarkers and provides a new strategy for constructing wearable, comfortable, highly integrated and self-powered biosensors. Graphical abstract: [Figure not available: see fulltext.]