Spinal cord injury (SCI) leads to disrupted communication between the brain and body, resulting in a loss of motor function and sensory deficit. Conventional electrical implants do not restore lost neural tissue, and their mechanical rigidity often leads to inflammation and device failure.​​ Biohybrid implants combine living cells with engineered materials designed to act as a scaffold and support for these cells to integrate into host tissue offering a promising strategy to regenerate connectivity by using seeded cells to replace damaged cells. A major challenge in developing these implants is identifying materials that replicate the mechanical compliance of neural tissue while simultaneously providing biochemical and biophysical cues that support neuronal adhesion, growth, and network formation. Conventional hydrogels offer excellent biocompatibility and mechanical similarity to target tissue but their surfaces are biologically passive and lack functional features that support neuronal health and mediated regeneration. By linking the material electroactivity to interfacial biology and neuronal morphogenesis, this work will clarify the mechanism through which electroactive polymers influence neural tissue engineering and provide foundational design principles for future biohybrid neural implants.  

Step placement is a key mechanism for maintaining dynamic stability during walking because it directly influences control of the body's center of mass. Variability in step placement, particularly in the medial-lateral direction, has been associated with gait stability and adaptations in neuromuscular control. Functional electrical stimulation (FES) and ankle exoskeleton assistance are two interventions that may alter these control strategies by modifying muscle activation and lower-limb mechanics. In this study, FES was applied to the soleus muscle to augment plantarflexor activation, while an ankle exoskeleton provided external plantarflexion assistance during walking. Ground reaction force data were collected during treadmill walking to quantify spatiotemporal gait parameters and step placement characteristics across walking conditions. Spatiotemporal parameters as well as ground reaction force kinetics variability were evaluated to assess how each intervention influenced gait stability and adaptation. Understanding how FES and exoskeleton assistance affect step placement may provide insight into locomotor adaptation mechanisms and inform the development of rehabilitation strategies, assistive devices, and fall-prevention interventions.