Engineering brain-on-a-chip platforms

The increasing prevalence of neurological and psychiatric diseases, such as Alzheimer disease and schizophrenia, necessitates the development of new research tools to investigate these diseases and develop effective treatments. Thus, in vitro brain models, such as brain-on-a-chip devices, have been developed to mimic in vivo biochemical and mechanobiological interactions and to monitor their electrochemical activity. In this Review, we discuss the technologies to build complex brain models. We discuss progress in microfluidic and semiconductor-based technologies that facilitate in vitro modelling of the blood–brain barrier and neuronal circuits to study pathophysiological processes. We further discuss advances in 3D tissue engineering, electrode strategies and materials that, when combined, could allow simulation of the native complexity of brain regions and the interrogation of their activity at cellular length scales. Furthermore, we explore the engineering challenges and opportunities for complex physiologically relevant brain-on-a-chip devices and their future progress.