Fabrication of stretchable PEDOT:PSS coated cotton fabric via LBL electrostatic self-assembly and its UV protection and sensing properties

The development and improvement of fabric-based stretchable strain sensors play a vital role in constructing wearable devices. In this paper, a flexible and sensitive cotton-based strain sensor for human motion monitoring was successfully developed by facile LBL-ESA (layer-by-layer electrostatic self-assembly) of chitosan (or chitosan quaternary ammonium salt) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), abbreviated to PEDOT:PSS. Chemical structure and microscopic morphology of the cotton fabric coated with PEDOT:PSS were measured using X-ray photoelectron spectroscopy, Raman spectroscopy, Scanning electron micrographs, Fourier transform infrared spectrometer and color strength (K/S value). Electrical conductivity of the fabric changed with the odd-even oscillations of K/S value of the cotton fabric. Furthermore, cotton fabric alternately deposited with five cycles reached the highest electrical conductivity (0.335 mS/cm). Meanwhile, the fabric presents excellent UV protection capacity (maximum UPF value of 385.07), which was 24.4 times of pristine cotton fabric (15.76). In addition, cotton fabric strain sensor coated by PEDOT:PSS could effectively detect finger and knee movements of humans, showing a promising prospect in the field of human rehabilitation training, real-time monitoring, and gesture recognition due to its good stability and being highly responsive.

Automated summary

A flexible and sensitive cotton-based strain sensor for human motion monitoring was successfully developed in this study. The sensor showed excellent electrical conductivity and UV protection capacity, and it has great potential for applications in human rehabilitation training, real-time monitoring, and gesture recognition.