Soft, conformal electrode platforms developed for high-fidelity neural signal acquisition, shown alongside anatomically representative head phantom systems used for controlled validation testing and device optimization.
This research focuses on developing soft, wearable neural-monitoring technology for mobile subjects. Rigid electrodes made of metal or plastic polymers are commonly used for EEG monitoring but pose injury risks to the user during falls or collisions. High-energy impacts at or near the electrode-skin interface can cause bruises, puncture wounds, or abrasions as electrodes jab into or drag across the skin. These safety concerns prevent the use of rigid electrodes in wearable devices for long-term neural monitoring in mobile subjects, thereby limiting the ability to collect high-quality longitudinal data for diagnostic or health-monitoring purposes.
We have developed a novel soft electrode that deforms as pressure increases, collapses if a pressure limit is exceeded, and returns to its original configuration as pressure returns to normal, all while maintaining electrical conductivity and scalp contact. The electrode body and legs are made of non-toxic soft silicone polymer. Electrode tips are made of silver/silver chloride, carbon-doped soft silicone polymer, or conductive ink. As pressure is placed on the top of the electrode, the legs deform while the tips remain in contact with the scalp, allowing us to continue recording neural activity. To test these electrodes, we use a head phantom made of ballistic gelatin that simulates the electromechanical properties of the human head. Using soft electrodes for biopotential measurement protects the patient in the event of impact while still maintaining electrode-skin contact, allowing us to apply these electrodes to long-term health monitoring scenarios.
There is a wide range of commercial applications for this technology. Patients living with neurological motor diseases or injuries have increased fall risk, but clinicians still need tools to evaluate their rehabilitation progress. Sending patients home with soft wearable technology allows us to collect long-term health data without risking injury to the subject, thereby better informing therapeutic interventions. Military applications include establishing baseline neural function at the start of training, monitoring competency and stress during training, and monitoring on the battlefield to reduce the risk of physical injury and mental disorders. Athletic performance can be enhanced during practice and game day by monitoring athletes’ stress levels and adapting coping strategies to keep them in peak condition.