3D Printable Dry EEG Electrodes with Coiled-Spring Prongs.

Masaya Kimura,Daiju Taketoshi,Nozomu Araki,Shin-Ichiro Nishida,Shintaro Nakatani

doi:10.3390/s20174733

Masaya Kimura, Daiju Taketoshi + Show 3 more

Open Access

https://doi.org/10.3390/s20174733

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Abstract

Various dry electroencephalography (EEG) electrodes have been developed. Dry EEG electrodes need to be pressed onto the scalp; therefore, there is a tradeoff between keeping the contact impedance low and maintaining comfort. We propose an approach to solve this tradeoff through the printing of complex-shaped electrodes by using a stereolithography 3D printer. To show the feasibility of our approach, we fabricated electrodes that have flexible fingers (prongs) with springs. Although dry electrodes with flexible prongs have been proposed, a suitable spring constant has not been obtained. In this study, the spring constant of our electrodes was determined from a contact model between the electrodes and the scalp. The mechanical properties and reproductivity of the electrodes were found to be sufficient. Finally, we measured the alpha waves when a participant opened/closed his eyes by using our electrodes.

Highlights

The brain–computer interface (BCI) has been studied as a communication technology between the brain and the device [1,2,3]
We propose an approach involving the use of an SLA 3D printer to fabricate EEG dry electrodes with coiled-spring prongs
We describe the process of our approach of printing dry electrodes with coiled-spring prongs

Summary

Introduction

The brain–computer interface (BCI) has been studied as a communication technology between the brain and the device [1,2,3]. EEG signals from the scalp using wet electrodes are widely used in communication [4,5,6], rehabilitation [7,8] due to these electrodes cost-effectiveness and high temporal resolution. Conductive gels and glues are required to attach wet electrodes to the scalp [9], and the impedance of such gels and glues worsens over time [10], which makes it difficult to obtain stable measurements over a long period of time. A dry electrode, which does not require any gel, is key for the spread of BCI technology because it reduces preparation time and enables long-term stable measurement. Various approaches for fabricating dry electrodes have been reported [11]

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Conclusion