posted on 2025-02-05, 01:43authored byDavide Vurro, Aris Liboà, Ilenia D’Onofrio, Giuseppe De Giorgio, Silvio Scaravonati, Marco Crepaldi, Alessandro Barcellona, Corrado Sciancalepore, Vardan Galstyan, Daniel Milanese, Mauro Riccò, Pasquale D’Angelo, Giuseppe Tarabella
The combination of green manufacturing approaches and
bioinspired
materials is growingly emerging in different scenarios, in particular
in medicine, where widespread medical devices (MDs) as commercial
electrodes for electrophysiology strongly increase the accumulation
of solid waste after use. Electrocardiogram (ECG) electrodes exploit
electrolytic gels to allow the high-quality recording of heart signals.
Beyond their nonrecyclability/nonrecoverability, gel drying also affects
the signal quality upon prolonged monitoring of biopotentials. Moreover,
gel composition often causes skin reactions. This study aims to address
the above limitation by presenting a composite based on the combination
of silk sericin (SS) as a structural material, poly(vinyl alcohol)
(PVA) as a robustness enhancer, and CaCl2 as a plasticizer.
SS/PVA/CaCl2 formulations, optimized in terms of weight
content (wt %) of single constituents, result in a biocompatible,
biodegradable “green” material (free from potentially
irritating cross-linking agents) that is, above all, self-adhesive
on skin. The best formulation, i.e., SS(4 wt %)/PVA(4 wt %)/CaCl2(20 wt %), in terms of long-lasting skin adhesion (favored
by calcium-ion coordination in the presence of environmental/skin
humidity) and time-stability of electrode impedance, is used to assemble
ECG electrodes showing quality trace recording over longer time scales
(up to 6 h) than commercial electrodes. ECG recording is performed
using customized electronics coupled to an app for data visualization.