Abstract
Soft electronic devices and sensors have seen great interest devoted to them for the purpose of recording and analyzing various electrophysiological signals including for the use of electrocardiography (ECG), electromyography (EMG), and electroencephalography (EEG). These newly designed and fabricated soft electrodes offer multiple advantages including the reduction of motion artifacts, lighter weight compared to traditional electrodes, improved comfort, and improved quality and length of use for long-term monitoring. While electrodes for ECG and EMG are planar electrodes to maximize the surface contact, this is not possible for electrodes for EEG due to their inability to penetrate the hair and make contact with the scalp. Therefore, EEG electrodes must have a different construction to circumvent this with the common method being a pillar- or spike- structured electrode. Hereafter, we report an elastomeric, conductive electrode consisting of a sponge-tipped pillar structure for contact of the scalp with a hollowed, column backing to clip into a traditional EEG headset for seamless integration of existing EEG monitoring systems. Our electrode exhibits reduced electrode-skin contact impedance, motion-artifact-tolerant recordings, and is a better option for long-term monitoring of EEG signals compared to commercially used electrodes. Our novel electrode consists of two functional parts bonded together with different material characteristics to utilize the best qualities of each material. One part of the electrode is the sponge-tipped pillar structures connected to a common base arranged in a 3x3 arrangement with the central pillar missing leaving a hole. It is comprised of a polydimethylsiloxane (PDMS) substrate coated with a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) conductive polymer using a simple dip-coating process. The pillars were made porous using a sacrificial sugar template that was then leached of the sugar using a hot water bath. The backing of the electrode is comprised of a polymer made of carbon black (CB) and PDMS where a central hollow column is connected to its own base that has been bonded to the base of the PEDOT:PSS coated PDMS functional part. Our novel, sponge-tipped electrode is a promising alternative to commercial electrodes due to its low-cost fabrication, comfortability, and capacity for high-quality, long term electroencephalogram recording.
Document Type
Article
Class Name
Electrical and Systems Engineering Undergraduate Research
Date of Submission
1-11-2024
Recommended Citation
Andersen, Ryan, "A Novel, Sponge-Tipped Electrode for Motion-Artifact-Tolerant Recording of High-Quality Electroencephalogram Signals" (2024). Electrical and Systems Engineering Undergraduate and Graduate Research. 25.
https://openscholarship.wustl.edu/eseundergraduate_research/25