Biomimetic Studies of Concussive Brain Injuries

Traumatic brain injury (TBI), a prevalent global health challenge, is associated with profound health and economic implications. TBI occurs due to a series of fluid-structure interactions (FSI) among the rigid skull, the cerebrospinal fluid (CSF), and the soft brain matter. This study has developed a novel and unique biomimetic approach, with the assistance of modern manufacturing and biological sciences, to examine two fundamental problems in bio-fluid mechanics. (1) the flow and pressurization of the CSF in the subarachnoid space (SAS) and (2) the response as well as the deformation of the brain matter as the head is exposed to sudden external impacts. The goal is to elucidate the critical role of the CSF in transmitting and mitigating external impacts and hence understand the mechanism of concussive brain injury.

We have integrated theoretical models and numerical simulations to capture CSF's pressure response and shear stress and the corresponding brain response. Furthermore, we have innovatively used a biomimetic model, an egg yolk within a rigid shell, to mirror and study the mechanics of the soft brain matter within the hard skull. This model provides fresh insights into the dynamics of concussive brain injury. We have also developed an artificial 'smart brain' within a transparent skull to further probe the effects of sudden impacts on the brain. This 'smart brain' model was subsequently applied to rodent brain matter, leading to new revelations about the brain tissue's response to external forces.

Our pioneering study uncovers fundamental mechanisms involved in brain injury and indicates the importance of CSF in transmitting and mitigating external impacts. It paves the way for future research, highlighting the need for a comprehensive exploration of brain injury mechanisms, and could inform the development of enhanced head protection strategies.