posted on 2025-01-15, 08:30authored byDian-Huan Ji, Yu-Feng Ni, Chien-Yin Lin, Mei-Yu Yeh
Conductive hydrogels, with their
unique combination of electrical
conductivity and stretchability, are emerging as critical components
for next-generation, flexible, and wearable sensors. In this work,
we aimed to develop a low-cost, easy-to-manufacture hydrogel sensor
using ionic compounds as the source of conductivity. Hydrogels were
synthesized using acrylamide, poly(ethylene glycol), and carboxymethyl
cellulose, with systematic variation of ionic compounds LiCl, NaCl,
and KCl, labeled as Li-CH, Na-CH, and K-CH, respectively, to explore
their effects on the nanostructure and mechanical properties of the
hydrogels. Among the different formulations, Na-CH demonstrated superior
performance with optimized elongation at break, tensile strength,
and toughness, highlighting the importance of ion selection in hydrogel
design. Na-CH also exhibited excellent stretchability, outstanding
transparency, and high sensitivity in detecting a wide range of body
movements, from large-scale gestures to subtle physiological signals
such as pulse detection. With its exceptional combination of transparency,
mechanical robustness, and repeatable sensing performance, Na-CH shows
great potential for future applications in flexible electronics, healthcare
monitoring systems, and smart display technologies.