Printed facial skin electrodes as sensors of emotional affect

Abstract

Electromyography of the zygomaticus major and the corrugator supercilii muscles is a well-established technique to capture positive and negative emotional affect. Despite the great potential, its wide adoption has been so far limited owing to several lingering technical limitations in contemporary electromyography electrodes. In this paper, we report on new printed electrode arrays, specifically designed to capture emotional affect, focusing on their unique and advantageous properties compared with conventional gelled electrodes. Inkjet-or screen-printing, combined with film cutting and lamination techniques, were used to produce customized electrode arrays. Conformity with the skin was guaranteed by printing on very thin and soft films. Unlike conventional gelled-surface electromyography electrodes, the printed electrode arrays are dry, allowing long-term and stable recording. Moreover, the large electrode arrays can be rapidly and conveniently placed on the subject's face, maintaining excellent electrode-skin compliance. Muscle localization was achieved despite inter-subject variability in facial features and electrode array position, as a result of high spatial resolution and source separation methodology. The presented electrode arrays open new opportunities in brain-machine interfacing, well-being investigations and mood monitoring.

Comparative Study of Printed Multilayer OLED Fabrication through Slot Die Coating, Gravure and Inkjet Printing, and Their Combination

“…The printing pattern can be easily changed or adjusted by changing the template [40,41]. Inkjet printing, as well as slot die coating, is a noncontact printing technique, and there are almost no limitations regarding the substrate; plastics, foils, glass, or textiles can be used [42][43][44]. However, the drawbacks are the special requirements and restrictions regarding the physical properties of the ink.…”

Electrophysiology Meets Printed Electronics: The Beginning of a Beautiful Friendship

“…In this case, silver traces are needed. Detailed discussion regarding ink and material properties is available in Inzelberg et al, 2018a.…”

“…Printing electrode arrays on flexible substrates, such as polyimide or polyester, was suggested as a mean to improve user convenience and electrode placement (on hair-free regions). Printed electrodes using various conductive inks, such as thermoplastic silver ink (Myllymaa et al, 2013a), carbon (Bareket et al, 2016; Inzelberg et al, 2018a) and poly(3,4-ethylenedioxythiophene, PEDOT) (Inzelberg et al, 2018a) were applied recently in several applications (Figure 1). Printed EEG electrode arrays, such as BrainStatus (Lepola et al, 2014; Miettinen et al, 2018) and cEEGGrid (Debener et al, 2015) opened new opportunities in neurological investigations and diagnostics.…”

“…Optimal material selection for printing the electrodes also permit safe artifact-free magnetic resonance imaging (MRI) and computerized tomography (CT) scanning (Myllymaa et al, 2013a,b). In the realm of sEMG, several studies demonstrated the benefits of printing (Scalisi et al, 2015; Zucca et al, 2015; Bareket et al, 2016; Ferrari et al, 2018; Inzelberg et al, 2018a). Ultrathin sEMG electrodes can maximize the contact area, lower the contact impedance, while reducing movement artifacts (Ferrari et al, 2018; Inzelberg et al, 2018a).…”

“…In the realm of sEMG, several studies demonstrated the benefits of printing (Scalisi et al, 2015; Zucca et al, 2015; Bareket et al, 2016; Ferrari et al, 2018; Inzelberg et al, 2018a). Ultrathin sEMG electrodes can maximize the contact area, lower the contact impedance, while reducing movement artifacts (Ferrari et al, 2018; Inzelberg et al, 2018a). High density printed sEMG emerges as a non-invasive method to acquire precise information of muscle activation by increasing the electrode number and enabling data analysis schemes (Marco, 2015; Scalisi et al, 2015).…”