A New Electroencephalography Electrode Design for Curly and Kinky Hair Types

Authors

• Elena Butler, University of Nebraska-LincolnFollow

First Advisor

Gregory Bashford

Second Advisor

Kevin Pitt

Committee Members

Deepak Keshwani, Catelyn Bridges

Date of this Version

5-2026

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Agricultural and Biological Systems Engineering

Under the supervision of Professors Gregory Bashford and Kevin Pitt

Lincoln, Nebraska, May 2026

Comments

Copyright 2026, Elena Butler. Used by permission

Abstract

Medical discrimination and implicit bias are present in both societal systems and into the design and validation of medical devices. Traditional electroencephalography (EEG) systems often fail to provide reliable physiological recordings on curly and kinky hair types (3B–4C), associated typically with Black American and others of African descent. EEG on these hair types often results in high electrode-scalp impedance, poor signal quality, and participant discomfort. Consequently, such technical biases contribute to the underrepresentation of these populations in neuroscience research and clinical diagnostics, while simultaneously limiting equitable access to EEG-based medical care.

To address this gap, a novel conductive electrode attachment was designed and prototyped with the intention of improving scalp contact without requiring specialized hairstyling or compromising signal quality. A structured engineering design process was followed including functional decomposition, morphological charts, Pugh matrix evaluation, and failure mode analysis. An electrode attachment was designed and optimized for textured hair.

The attachment design leverages a comb-like geometry inspired by dry EEG electrodes, allowing the structure to penetrate dense and/or textured hair to reach the scalp more effectively. A conductive pathway was integrated from the scalp interface to the original electrode using sintered silver pellet electrodes housed within a 3D-printed shell and electrically insulated to ensure signal integrity and user safety.

This thesis yielded a newly designed and prototyped electrode specifically made with these hair types (curly and kinky) in mind. A pilot study involving three participants was conducted to test the electrode attachment. Preliminary analysis revealed that the new attachment was able to meet an impedance threshold of less than 10 kOhms, acquire event related potentials (ERP’s), and gel quicker than the original standard flat disc electrodes.

These findings suggest that the proposed electrode attachment can enhance EEG inclusivity for individuals with textured hair, improving both research generalizability and clinical equity. Future work will expand integration to full-cap configurations and optimized designs for broader clinical and research applications.

Advisors: Gregory Bashford and Kevin Pitt