Journal Article

Solvent Treatment of Wet-Spun PEDOT: PSS Fibers for Fiber-Based Wearable pH Sensing

Crean, Carol, Smith, Rachel E., Garcia-Torres, Jose, Reid, Daniel O., Watts, John F.

2019

Overview

There is a growing desire for wearable sensors in health applications. Fibers are inherently flexible and as such can be used as the electrodes of flexible sensors. Fiber-based electrodes are an ideal format to allow incorporation into fabrics and clothing and for use in wearable devices. Electrically conducting fibers were produced from a dispersion of poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT: PSS). Fibers were wet spun from two PEDOT: PSS sources, in three fiber diameters. The effect of three different chemical treatments on the fibers were investigated and compared. Short 5 min treatment times with dimethyl sulfoxide (DMSO) on 20 μm fibers produced from Clevios PH1000 were found to produce the best overall treatment. Up to a six-fold increase in electrical conductivity was achieved, reaching 800 S cm−1, with no loss of mechanical strength (150 MPa). With a pH-sensitive polyaniline coating, these fibers displayed a Nernstian response across a pH range of 3.0 to 7.0, which covers the physiologically critical pH range for skin. These results provide opportunities for future wearable, fiber-based sensors including real-time, on-body pH sensing to monitor skin disease.

• Publisher: MDPI AG,MDPI
• Subject: Conductivity / Dimethyl Sulfoxide - chemistry / Electric Conductivity / Electrochemical Techniques - instrumentation / Electrochemical Techniques - methods / Electrodes / fiber electrode / Formates - chemistry / Hydrogen-Ion Concentration / pedot: pss / Polymers / Polystyrenes - chemistry / Potassium / Solvents / Solvents - chemistry / Spectrum analysis / Spectrum Analysis, Raman / Sulfuric acid / Sulfuric Acids - chemistry / Tensile Strength / Textiles / Thiophenes - chemistry / Voltammetry / Wearable Electronic Devices / wearable sensor