Chapters authored
Hydrogels and the Brain: Recent Advances in Neuroelectronic Devices
Neural signals are transmitted through the brain via electrical impulses and chemical messengers, carrying crucial details about the brain’s functional mechanisms. To profoundly understand brain function, neural electrodes are needed to sense these signals. However, traditional rigid electrodes struggle with poor contact on curved surfaces like brain tissue, often causing damage or inflammation during implants. To overcome this challenge, hydrogels, as an effective solution for neuroelectronic applications, are promising due to their biocompatibility in contact with the human body. Hydrogel-based or hydrogel-modified nano/micro-structured electrodes can solve the ineffective contact between soft tissue and rigid electronics, enhancing signal detection and safety. By incorporating conductive materials, such as metal-based nanostructures, conductive polymers, and carbon-based nanomaterials, hydrogel neural electrodes achieve low impedance, high signal fidelity, and long-term stability for neuroelectronic devices. This chapter delves into hydrogel design basics and synthesis routes, from simple mixing to advanced crosslinking. We’ll spotlight real-world hydrogel-based neuroelectronic applications in wearable and implantable neural devices, including electrochemical sensors (ECS) for neurotransmitters, microelectrode arrays (MEAs) for electrocorticography (ECoG) and intracortical aims, and EEG electrodes. In addition, we will introduce the future outlook and emerging technologies in the field of neuroelectronics.
Part of the book: Hydrogels