Microtube-integrated chips for modular electrical stimulation and 3D confined neural network growth

In vitro neural networks offer a simplified model to study brain nervous system functions and represent a vital platform for investigating cerebral neural activities. Microelectrode array (MEA) chips are commonly used to construct modular neural networks and enable electrical stimulation and recording for uncovering signal generation and conduction mechanisms. However, conventional two-dimensional (2D) MEA chips face significant limitations, including restricted neuronal growth dimensions and insufficient neuron density. Herein, we present a novel micro-integrated chip featuring a three-dimensional (3D) physical microtube array that facilitates the regulated, confined growth of neurons. The microtube array not only provides a 3D microenvironment for neuronal growth and differentiation but also enhances neuronal network density and structural organization. Furthermore, by integrating the microtube array with a customized MEA, precise electrical stimulation can be applied to modular neural networks. Experimental results demonstrate that electrical stimulation effectively promotes the formation of connection pathways between adjacent 3D neural networks. Variable-parameter electrical stimulation experiments reveal that increasing voltage enhances the Young's modulus of neurons, highlighting the method's role in supporting the stable development of neuronal networks. This modular culture platform, combined with precise electrical stimulation, paves the way for constructing high-density 3D neuronal networks and enables synchronous control of modular neural activities. The proposed approach holds significant potential for advancing applications in neuroscience, tissue engineering, and organ-on-chip technologies.