Comparative Analysis of Electrode Coatings for Safe, Low-Impedance, and Selective Current Delivery
Faculty Mentor Information
Dr. Benjamin Johnson, Boise State University; and Dr. Morgan Riley, Boise State University
Presentation Date
7-15-2026
Abstract
Electrical stimulation of peripheral nerves is used to treat a wide range of conditions, including epilepsy, depression, incontinence, rheumatoid arthritis, and many other disorders involving abnormal nerve activity. Electrical stimulation is typically delivered through cuffs that wrap around the target nerve. However, low-cost nerve cuffs with high spatial resolution for selective stimulation are not readily available to many researchers. To address this need, we developed flexible printed circuit board-based nerve cuffs with microscale electrodes and evaluated post-processing methods to improve their stimulation performance. Electrode performance depends strongly on impedance, charge-injection capacity, and long-term coating stability. We evaluated three electrode surfaces: bare ENIG gold, hand applied PEDOT:PSS ink, and laser-induced graphene (LIG). LIG electrodes were fabricated on polyimide by optimizing laser speed and power to achieve ~11 μm ablation depth. This removed the top polyimide layer without damaging the underlaying metal. Optical inspection and electrical testing confirmed successful LIG electrode formation. All three electrode types were assessed for impedance, charge-injection capacity, and long-term stability. These results provide insight into which materials best support safe and stable electrical stimulation for low-cost, selective neuromodulation of peripheral nerves.
Comparative Analysis of Electrode Coatings for Safe, Low-Impedance, and Selective Current Delivery
Electrical stimulation of peripheral nerves is used to treat a wide range of conditions, including epilepsy, depression, incontinence, rheumatoid arthritis, and many other disorders involving abnormal nerve activity. Electrical stimulation is typically delivered through cuffs that wrap around the target nerve. However, low-cost nerve cuffs with high spatial resolution for selective stimulation are not readily available to many researchers. To address this need, we developed flexible printed circuit board-based nerve cuffs with microscale electrodes and evaluated post-processing methods to improve their stimulation performance. Electrode performance depends strongly on impedance, charge-injection capacity, and long-term coating stability. We evaluated three electrode surfaces: bare ENIG gold, hand applied PEDOT:PSS ink, and laser-induced graphene (LIG). LIG electrodes were fabricated on polyimide by optimizing laser speed and power to achieve ~11 μm ablation depth. This removed the top polyimide layer without damaging the underlaying metal. Optical inspection and electrical testing confirmed successful LIG electrode formation. All three electrode types were assessed for impedance, charge-injection capacity, and long-term stability. These results provide insight into which materials best support safe and stable electrical stimulation for low-cost, selective neuromodulation of peripheral nerves.