Hierarchical Surface Restructuring of Ultra‐Thin Electrodes and Microelectrode Arrays for Neural Interfacing with Peripheral and Central Nervous Systems

Long‐term implantable neural interfacing devices are crucial in neurostimulation for treating various neurological disorders. These devices rely heavily on electrodes and microelectrode arrays. As the invasiveness of these electrodes increases—particularly for peripheral and central nervous system applications—both potential benefits and risks of adverse side effects to the patient rise. To mitigate risks and enhance device performance and longevity, electrodes for such invasive applications must be thin, flexible, and have small contacts. However, these features typically reduce the geometric surface area and electrochemical performance of the electrodes, diminishing treatment benefits. This report explores the feasibility and advantages of using femtosecond laser hierarchical surface restructuring (HSR) technology to improve electrochemical performance without compromising the structural integrity of ultra‐thin (