Conducting polymer tattoo electrodes in clinical electro- and magneto-encephalography

Abstract

Temporary tattoo electrodes are the most recent development in the field of cutaneous sensors. They have successfully demonstrated their performances in the monitoring of various electrophysiological signals on the skin. These epidermal electronic devices offer a conformal and imperceptible contact with the wearer while enabling good quality recordings over time. Evaluations of brain activity in clinical practice face multiple limitations, where such electrodes can provide realistic technological solutions and increase diagnostics efficiency. Here we present the performance of inkjet-printed conducting polymer tattoo electrodes in clinical electroencephalography and their compatibility with magnetoencephalography. The working mechanism of these dry sensors is investigated through the modeling of the skin/electrode impedance for better understanding of the biosignals transduction at this interface. Furthermore, a custom-made skin phantom platform demonstrates the feasibility of high-density recordings, which are essential in localizing neuropathological activities. These evaluations provide valuable input for the successful application of these ultrathin electronic tattoos sensors in multimodal brain monitoring and diagnosis.

Toward the Use of Temporary Tattoo Electrodes for Impedancemetric Respiration Monitoring and Other Electrophysiological Recordings on Skin

“…Epidermal electronics fabricated on top of decal transfer paper enable an easy manipulation and reliable release/transfer on the skin (or other target surfaces), which are crucial from an end-user standpoint. In particular, temporary tattoo electrodes (TTEs) technology has been successfully demonstrated to work as a promising technology for surface electrophysiological (sEP) recordings, including electromyography (EMG), electrocardiography (ECG) and electroencephalography (EEG), overcoming the limitations of traditional disposable Ag/AgCl electrodes [ 13 , 14 , 18 , 19 , 22 ]. These ultrathin nanosheets are composed of conducting polymer complex poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) printed on top of a thin (~500 nm) ethylcellulose layer, releasable from a decal transfer paper.…”

Ultrathin, Ultra‐Conformable, and Free‐Standing Tattooable Organic Light‐Emitting Diodes

“…developed conformable electromyography (EMG) electrodes by deposition of ultrathin conductive poly(3,4‐ethylendioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) onto TT with an overall thickness ≈500 nm. [ 4 ] Further improvements led to multi‐electrode temporary tattoo electrodes which were successfully tested in EMG as well as in electrocardiography (ECG) [ 5 ] and electroencephalography (EEG) [ 25 ] providing for the first time, an easy to use, dry, unperceivable skin contact electrode which also proved to be resilient to perforation by growing hairs. Wang et al.…”

Electrical properties, accuracy, and multi-day performance of gelatine phantoms for electrophysiology

“…Some research groups have even applied transcranial Electrical Stimulation (tES) to these phantoms to investigate the tES artefact removal problem from EEG where a known EEG signal can now be provided [16], [17]. [18] suggested agar as an alternative to gelatine for the recording of slow EEG potentials, while recently [19] made use of an agarose gel swollen with a saline solution.…”

“…[13] is a one-page investigation on tuning the electrical properties of gelatine phantoms over a 5 Hz to 1.5 kHZ range using different concentrations of NaCl, but there is no information on how this compares to biological tissues, or how the electrical properties change over time. [17], [19] match only the d.c. conductivity and do not consider the a.c. frequency response. [32] investigated the a.c. properties of gelatine and agar phantoms over the range 100-500 Hz with varying levels of NaCl, but again did not compare these to biological tissues, or how the electrical properties change over time.…”