Smart and functional fibers for medical pressure sensors

• Main Author: Gouveia, Sofia Reis Sarmento Homem de
• Publication Date: 2020
• Format: Master thesis
• Language: eng
• Source: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Download full: http://hdl.handle.net/10362/112981
• topic: Pressure sensors; ICPs; Piezoresistive; Polymerization; Polypyrrole; Poly(3,4-ethylenedioxythiophene); Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Médica

One of the biggest problems that affect bedridden patients are pressure sores. This work explores the functionalization of commercially available textiles with Intrinsically Conductive Polymers (ICPs) such as Polypyrrole (PPy) and Poly(3,4-ethylenedioxythiophene) (PEDOT). Two in-situ polymerization methods were evaluated in detail: Liquid phase polymerization (LPP) and Vapor phase polymerization (VPP). After optimization, both methodologies led to an improvement of fabric conductivity. Morphological and electrical characterization showed that the VPP of EDOT produced more uniformly coated fibers with higher electrical conductivity properties (4.59×10-3±5.54×10-4 S/cm using the in-plane configuration and 9.33×10-5±2.21×10-5 S/cm using the transversal configuration, for a reaction time of 30 minutes). Additionally, the electrical stability of func-tionalized textiles was evaluated with time and after several washing cycles. It was possible to conclude that PEDOT-coated fibers using VPP methodology exhibited higher electrical con-ductivity values after 10 complete washing cycles (with a decay of 99% of its initial conductiv-ity). Finally, the pressure sensing ability of the fabrics was tested using a home-made setup. Polypyrrole showed better electrical resistance recovery for lower weights, 40 grams, and PE-DOT exhibited a better behavior for higher weights, 100 and 200 grams.