Epidermal Electrodes with Ferrimagnetic/Conductive Properties for Biopotential Recordings

Bioengineering (Basel). 2022 May 11;9(5):205. doi: 10.3390/bioengineering9050205.

Abstract

Interfacing ultrathin functional films for epidermal applications with external recording instruments or readout electronics still represents one of the biggest challenges in the field of tattoo electronics. With the aim of providing a convenient solution to this ever-present limitation, in this work we propose an innovative free-standing electrode made of a composite thin film based on the combination of the conductive polymer PEDOT:PSS and ferrimagnetic powder. The proposed epidermal electrode can be directly transferred onto the skin and is structured in two parts, namely a conformal conductive part with a thickness of 3 μm and a ferrimagnetic-conductive part that can be conveniently connected using magnetic connections. The films were characterized for ECG recordings, revealing a performance comparable to that of commercial pre-gelled electrodes in terms of cross-spectral coherence, signal-to-noise ratio, and baseline wandering. These new, conductive, magnetically interfaceable, and free-standing conformal films introduce a novel concept in the domain of tattoo electronics and can set the basis for the development of a future family of epidermal devices and electrodes.

Keywords: ECG recordings; PEDOT:PSS free-standing films; epidermal electrodes; ferrimagnetic conductive films; magnetic connectors.

Grants and funding

This research was partially funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 882897–Search & Rescue project. Part of this research was supported by the Italian Government “Progetti di Interesse Nazionale (PRIN)” under the grant agreement 2017RR5EW3—ICT4MOMs project.