Josef Goding

A group of leaders in neural engineering collaborated to develop a roadmap to navigate the future of neural engineering. We covered a range of themes, including brain machine interfaces, neural modeling, artificial intelligence and machine learning, neural interfaces, neural imaging, augmented rehabilitation, and neuromaterials. For each topic we reviewed the current status, identified current and future challenges, and speculated on the emerging and necessary advances in science and technology to meet these challenges. Neural engineering will continue to yield the approaches and insights that advance the diagnosis and treatment of nervous system disorders, as well as provide new understanding of neural function.

Objective. Peripheral nerve stimulation (PNS) offers therapeutic benefits across numerous clinical applications but remains limited by poor spatial selectivity in mixed nerves. This study aimed to evaluate whether a fully polymeric, transverse, multipolar nerve cuff can achieve selective fascicular activation and to assess the predictability of such selectivity using imaging-informed computational models. Approach. A flexible, fully polymeric nerve cuff fabricated from a conductive elastomer (CE) was developed and evaluated ex vivo on rat sciatic nerves. Compound nerve action potentials were recorded from individual fascicles to quantify selectivity across a wide range of stimulation parameters. The non-metallic electrodes enabled microCT-based three-dimensional reconstruction of nerve–electrode geometries without imaging artifacts, which were incorporated into anatomically accurate simulations using the ASCENT modeling pipeline. Main results. Ex vivo experiments demonstrated reliable neural recordings and high levels of fascicular selectivity (selectivity index > 0.65 in each fascicle). Imaging-informed simulations reproduced selective activation patterns in some cases but showed systematic discrepancies in both selectivity magnitude and electrode–fascicle correspondence, particularly for sural and tibial fascicles. Simulated outcomes were more sensitive to neuroanatomical variability than experimental results, highlighting limitations in current modeling assumptions. Significance. These findings validate fully polymeric CE cuffs as effective alternatives to metallic nerve interfaces for selective PNS. The study also demonstrates the value of combining microCT imaging with computational modeling to interrogate and refine predictive frameworks, underscoring the need for improved tissue and electrode modeling to advance spatially selective PNS technologies.

Bionic implants are increasingly used to restore neural function yet, achieving a chronically stable neural interface remains challenging. Biohybrid neurotechnologies aim to overcome this limitation by integrating living tissue or other biological components that can promote long‐term performance and functional integration with the nervous system. However, existing living biomaterial coatings often lack the physiological complexity, cellular heterogeneity, and neurotrophic support required to sustain neural network formation. Here, a modular strategy is presented which leverages astrocyte‐guided mechanisms of neural network development. A biosynthetic hydrogel is developed using norbornene‐functionalized poly(vinyl alcohol) and gelatin (PVA‐GEL), crosslinked via visible light‐triggered thiol‐ene chemistry, to yield bioactive and highly tunable scaffolds. A systematic characterization varying gelatin content and polymer weight enables the identification an optimal formulation to promote astrocytic growth, while maintaining mechanical stability and degradation profiles that are compatible with brain implants. Co‐encapsulation with neural progenitors promotes neuronal differentiation, neurite outgrowth, and the formation of synaptically competent networks. The construct develops into functional interfaces when in contact with brain tissue ex vivo, highlighting its potential as a biohybrid electrode coating. This work lays the foundation for the development of biologically guided biohybrid interfaces, toward seamless integration with the nervous system.

Bionic implants are increasingly used to restore neural function yet achieving a chronically stable neural interface remains challenging. Biohybrid neurotechnologies aim to overcome this limitation by integrating living tissue components that can promote long-term performance and functional integration with the nervous system. However, existing biomaterial coatings often lack the physiological complexity, cellular heterogeneity, and neurotrophic support required to sustain neural network formation. Here, we present a modular strategy which leverages astrocyte-guided mechanisms of neural network development. A biosynthetic hydrogel was developed using norbornene-functionalized poly(vinyl alcohol) and gelatin (PVA-GEL), crosslinked via visible light-triggered thiol–ene chemistry, to yield bioactive and highly tuneable scaffolds. A systematic characterization varying gelatin content and polymer weight enabled the identification an optimal formulation to promote astrocytic growth, while maintaining mechanical stability and degradation profiles that are compatible with brain implants. Co-encapsulation with neural progenitors promoted neuronal differentiation, neurite outgrowth, and the formation of synaptically competent networks. The construct developed into functional interfaces when in contact with brain tissue ex vivo , highlighting its potential as a biohybrid electrode coating. This work lays the foundation for the development of biologically guided biohybrid interfaces, towards seamless integration with the nervous system.

The study describes the development of a multi-layered electrode coating that was electrochemically characterised. A numerical model of the electric field was developed, and astrocytes were encapsulated within the biosynthetic layer.

Intrinsically conductive polymers have garnered a great deal of attention for use in medical and bioelectronic applications. Despite this, challenges associated with the mechanical stability, processability, and fabrication of conducting polymers have limited their utility. To circumvent these limitations, thiophene substituted 2‐oxazolines (2Ox) and 2‐oxazines (2Ozi) are introduced, which can be polymerized to form a thermally stable and potentially melt‐processable polymers as precursors for conductive polymers. A series of such monomers are synthesized and yields above 50% are obtained for gram scale reactions. The monomers can subsequently be polymerized using standard cationic ring‐opening methods to yield thiophene‐bearing poly(2‐oxazoline)s (POx) and poly(2‐oxazine)s (POzi) with narrow to moderate dispersity. The polymers exhibit glass transition temperatures between 50 °C and 100 °C and thermal stability beyond 250 °C. Moreover, random copolymers can be produced by introducing aliphatic 2‐oxazolines during polymer synthesis, which facilitates tailoring of the polymer properties and may enable new applications in melt extrusion printing or electrospinning of precursors for conducting polymer systems. Overall, a facile approach is described for the synthesis of thiophene‐functionalized monomers and polymers, providing covalent integration of thiophenes that opens new avenues toward the generation of functional and stimuli‐responsive biomaterials.

The realm of implantable bioelectronics represents a frontier in medical science, merging technology, biology, and medicine to innovate treatments that enhance, restore, or monitor physiological functions. This field has yielded devices like cochlear implants, cardiac pacemakers, deep brain stimulators, and vagus nerve stimulators, each designed to address a specific health condition, ranging from sensorineural hearing loss to chronic pain, neurological disorders, and heart rhythm irregularities. Such devices underscore the potential of bioelectronics to significantly improve patient outcomes and quality of life. Recent technological breakthroughs in materials science, nanotechnology, and microfabrication have enabled the development of more sophisticated, smaller, and biocompatible bioelectronic devices. However, the field also encounters challenges, particularly in extending the capabilities of devices such as retinal prostheses, which aim to restore vision but currently offer limited visual acuity. Research in implantable bioelectronics is highly timely, driven by an aging global population with a growing prevalence of chronic diseases that could benefit from these technologies. The convergence of societal health needs, advancing technological capabilities, and a supportive ecosystem for innovation marks this era as pivotal for bioelectronic research.

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 reasons, dry electrodes are preferable during surface electromyography (sEMG) due to their convenience, durability, and longevity. Dry conductive elastomers (CEs) combine conductivity, flexibility, and stretchability. In this study, CEs combining poly(3,4-ehtylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) in polyurethane are explored as dry, skin contacting EMG electrodes. This study compares these CE electrodes to commercial wet Ag/AgCl electrodes in five subjects, classifying four movements: open hand, fist, wrist extension, and wrist flexion. Classification accuracy is tested using a backpropagation artificial neural network. The control Ag/AgCl electrodes have a 98.7% classification accuracy, while the dry conductive elastomer electrodes have a classification accuracy of 99.5%. As a conclusion, PEDOT based dry CEs were shown to successfully function as on-skin electrodes for EMG recording, matching the performance of Ag/AgCl electrodes, while addressing the need for minimal skin prep, no gel, and wearable technology.