Fully 3D‐Printed Cuff Electrode for Small Nerve Interfacing

Abstract

Interfacing with the peripheral nervous system is a powerful method for diagnosing and treating several diseases, such as drug‐resistant epilepsy and depression. In most clinical applications, large nerves such as the vagus and the hypoglossal nerve are targeted. Large nerves carry multiple nerve fibers, and maintaining selectivity of a specific target response demands complex stimulation strategies. As the large trunks bifurcate toward their distal ends, their diameter and number of comprised fibers reduce. Consequently, interfacing small nerves can provide increased fiber selectivity. However, their small size presents challenges to the fabrication and implantation of suitable electrodes due to their fragility and constrained environments. Here, a cuff electrode that combines two‐photon stereolithography and 3D inkjet printing techniques for the selective interfacing of small nerves in vivo is introduced. The device is easy to implant, and its size can be tailored for specific nerve dimensions. Its capability to record and selectively stimulate is demonstrated by targeting a locust's hind leg nerve.

Recent advances and future directions of 3D to 6D printing in brain cancer treatment and neural tissue engineering

“…The system employs commercially available electrical components and is 3D-printed to facilitate the adoption and implementation of future bioelectronic therapies [88]. Zurita et al [89] investigated the potential of interfacing with the PNS to diagnose and treat drugresistant epilepsy, depression, and similar diseases. They stressed the importance of targeting large nerves such as the vagus and hypoglossal nerves, which convey multiple nerve fibers and require complex stimulation strategies.…”

“…The electrode is simple to implant and can be customized to fit specific nerve dimensions. They demonstrated its ability to record and selectively stimulate nerves by focusing on the hind leg nerve of a locust [89]. In another study, the implantation of brain-computer interfaces (BCIs) in the brain, employing electrodes to record and stimulate neural signals, was discussed.…”

Use of 3D Printing Techniques to Fabricate Implantable Microelectrodes for Electrochemical Detection of Biomarkers in the Early Diagnosis of Cardiovascular and Neurodegenerative Diseases

“…3D printing materials, such as polymers and metals, may not be biocompatible, and their degradation products may cause toxicity. Therefore, developing biocompatible materials and coatings for 3D-printed microelectrodes is essential. , …”

“…Therefore, developing biocompatible materials and coatings for 3D-printed microelectrodes is essential. 254,255 Implantable microelectrodes must also be mechanically stable to maintain their function over an extended period. 3D printing can produce highly precise microelectrodes, but they may be prone to mechanical failure due to their small size and the stress they experience during insertion and use.…”

Thermoformed Parylene‐C Cuff Electrodes for Small Nerve Interfacing

“…The mechanical attachment to small nerves is crucial since the stimulation efficiency degrades with the distance between the electrode and the nerve tissue. [56,57] This reduction in efficiency happens because the stimulation signal is partially shunted through the electrolyte present in the electrode-nerve gap. Our prefolded design minimizes this gap because it conforms to the shape of the nerve, gently displacing the electrolyte in the gap and minimizing the contact distance.…”