Josef Alexander Goding

Imperial College London | Imperial · Department of Bioengineering

Conventional wet Ag/AgCl electrodes are widely used in electrocardiography, electromyography (EMG), and electroencephalography (EEG) and are considered the gold standard for biopotential measurements. However, these electrodes require substantial skin preparation, are single use, and cannot be used for continuous monitoring (>24 h). For these reaso...

The application of biomimetic technologies to neural interfaces seeks to improve the long-term safety and performance of implantable systems. These biomimetic approaches encompass methods that alter the biological environment through mechanical, topographical and biological approaches. This chapter examines recent developments in bioinspired soft a...

Patterning of conducting polymers (CPs) into fully functioning devices remains a challenge for the creation of polymeric bioelectronics. Presently, the most successful method for patterning CPs is preprocess blending with structural components and using either subtractive or additive processes to produce the desired design. This work focuses on the...

Neural interfaces (NIs) have traditionally used inorganic device constructs paired with electrical stimulation to bypass injured or diseased electroactive tissues. These bioinert devices have significant impact on the neural tissue, being synthetic and causing large volumetric changes to the biological environment. The concept of biomimicry has bec...

Soft, flexible polymer-based bioelectronics are a promising approach to minimize the chronic inflammatory reactions associated with metallic devices, impairing long-term device reliability and functionality. This work demonstrates the fabrication of conductive elastomers (CEs) consisting of chemically synthesized poly(3,4-ethylenedioxythiophene) (P...

Brain–computer interfaces (BCIs) provide bidirectional communication between the brain and output devices that translate user intent into function. Among the different brain imaging techniques used to operate BCIs, electroencephalography (EEG) constitutes the preferred method of choice, owing to its relative low cost, ease of use, high temporal res...

Conducting polymers (CPs) possess unique electrical and electrochemical properties and hold great potential for different applications in the field of bioelectronics. However, the widespread implementation of CPs in this field has been critically hindered by their poor processibility. There are four key elements that determine the processibility of...

Hydrogel materials have been employed as biological scaffolds for tissue regeneration across a wide range of applications. Their versatility and biomimetic properties make them an optimal choice for treating the complex and delicate milieu of neural tissue damage. Aside from finely tailored hydrogel properties, which aim to mimic healthy physiologi...

There is a critical need to transition research level flexible polymer bioelectronics toward the clinic by demonstrating both reliability in fabrication and stable device performance. Conductive elastomers (CEs) are composites of conductive polymers in elastomeric matrices that provide both flexibility and enhanced electrochemical properties compar...

The development of 3D neural tissue analogs is of great interest to a range of biomedical engineering applications including tissue engineering of neural interfaces, treatment of neurodegenerative diseases and in vitro assessment of cell-material interactions. Despite continued efforts to develop synthetic or biosynthetic hydrogels which promote th...

Conductive polymer (CP)–elastomer composites have been proposed as an alternative to the metals conventionally used for bioelectronic devices. Being softer and more stretchable than metals such as platinum and gold, they can mitigate the adverse effects associated with mechanical mismatch and fatigue failure. Such composites are conventionally made...

Neural interface research and development covers a wide spectrum of topics, spanning basic neuroscience to design of implantable devices. In vitro studies have been an integral part of this research and form the basis of regulated preclinical studies. Historically, 2D cell cultures have provided substantial data on neural interfaces; however, these...

Localized and actively controlled delivery of drugs presents an opportunity for improving bioavailability, therapeutic efficacy, and long-term treatment of injury or disease. Conductive polymer (CP) based systems present a unique opportunity for using inherent electrochemical and actuating properties to ensure that drugs are delivered or retained u...

Flexible polymeric bioelectronics have the potential to address the limitations of metallic electrode arrays by minimizing the mechanical mismatch at the device-tissue interface for neuroprosthetic applications. This work demonstrates the straightforward fabrication of fully organic electrode arrays based on conductive elastomers (CEs) as a soft, f...

Hydrogels have been applied across a wide range of biomedical applications due to their versatility, but more recently have garnered interest as materials in bioelectronics due to the capacity to tailor their mechanical and biological properties. Hydrogel coatings in particular have been used to impart softness at the bionic device interface, deliv...

Nerve block via electrical stimulation of nerves requires a device capable of transferring large amounts of charge across the neural interface on chronic time scales. Current metal electrode designs are limited in their ability to safely and effectively deliver this charge in a stable manner. Conductive hydrogel (CH) coatings are a promising altern...

Existing bionic implants use metal electrodes, which have low charge transfer capacity and poor tissue integration. This limits their use in next-generation, high resolution devices. Coating and other modification techniques have been explored to improve the performance of metal electrodes. While this has enabled increased charge transfer propertie...

Nerve block waveforms require the passage of large amounts of electrical energy at the neural interface for extended periods of time. It is desirable that such waveforms be applied chronically, consistent with the treatment of protracted immune conditions, however current metal electrode technologies are limited in their capacity to safely deliver...

The bypassing of degenerated photoreceptors using retinal neurostimulators is helping the blind to recover functional vision. Researchers are investigating new ways to improve visual percepts elicited by these means as the vision produced by these early devices remain rudimentary. However, several factors are hampering the progression of bionic tec...

A living electrode construct that enables integration of cells within bionic devices has been developed. The layered construct uses a combination of non-degradable conductive hydrogel and degradable biosynthetic hydrogel to support cell encapsulation at device surfaces. In this study, the material system is designed and analyzed to understand the i...

Conducting hydrogels (CHs) are an emerging technology in the field of medical electrodes and brain-machine interfaces. The greatest challenge to the fabrication of CH electrodes is the hybridization of dissimilar polymers (conductive polymer and hydrogel) to ensure the formation of interpenetrating polymer networks (IPN) required to achieve both so...

Conductive composites based on conductive polymers (CPs) have enabled the development of a range of materials for biomedical applications that can be tailored to improve material properties critical to long-term performance of implantable devices. Nonconductive polymers can be used to impart tailored presentation of biomolecules and improve the bri...

The development of the next generation electrode interfaces for neural prosthetic devices requires high-through- put multifaceted testing strategies to assess material interac- tions with both peripheral and central nervous system (CNS) immune cells. The utility of a primary astrocyte enriched glial cell culture was assessed as a potential in vitro...

Biological responses to neural interfacing electrodes can be modulated via biofunctionalisation of conducting polymer (CP) coatings. This study investigated the use of small bioactive molecules with anti-inflammatory properties. Specifically, anionic dexamethasone phosphate (DP) and valproic acid (VA) were used to dope the CP poly(ethylenedioxythio...

Conductive polymer (CP) coatings can improve the performance of metallic bioelectrodes in implantable devices, a benefit which is partially attributed to the “softer” material interface. However, due to the nature of CP fabrication on metallic substrates, accurate quantification of mechanical properties has been difficult to achieve. This study dem...

A hybrid system for producing conducting polymers within a doping hydrogel mesh is presented. These conductive hydrogels demonstrate comparable electroactivity to conventional conducting polymers without requiring the need for mobile doping ions which are typically used in literature. These hybrids have superior mechanical stability and a modulus s...

The conducting polymer poly(ethylene dioxythiopene) (PEDOT) has been investigated as a coating for visual prosthesis electrode arrays. The prototype electrode array was coated with PEDOT doped with two conventional anions: paratoluene sulfonate (pTS) and lithium perchlorate (LiClO4). PEDOT variants were analyzed for charge injection limit, electroc...