In today's digital era, educational games stand as an important tool to revolutionize learning and teaching methodologies. They cater to the diverse learning styles of individuals, making the process of knowledge acquisition more interactive and engaging. They also offer a safe environment where mistakes become opportunities for learning rather than sources of discouragement. For many individuals, educational games provide immediate feedback, enhancing the pace at which they grasp concepts. This report presents an educational video game focused on protocols related to microfabrication. The game aims to provide learners with an interactive platform to experience and understand crucial aspects of the microfabrication, including cleanroom attire and aligning wafers to photomasks. In the gowning section of the game, students will learn about the sequence of putting on cleanroom attire for working in the cleanroom. The mask alignment section of the game introduces the key procedure of photolithography. Students will practice how to accurately align wafers with existing patterns to photomasks. The game provides an innovative low-stakes virtual learning environment to practice gowning and mask alignment procedures. The game aims to train students with minimal experience and invoke an interest the field of microfabrication towards building a workforce on semiconductor manufacturing.

The gut facilitates digestion and absorption of nutrients, while the brain carries out many higher-level functions, including cognition and interaction with the peripheral nervous system. Despite the anatomical separation between the gut and the brain, there is constant communication between the two. Signals from the brain are sent to the gut to regulate digestion, while satiety signals are sent from the gut back to the brain. A healthy gut microbiome promotes homeostasis between the gut and brain, where microbiome dysbiosis can lead to an increase in intestinal epithelium permeability and leakage of microbial factors across the epithelium, all of which playing a role in diseases such as diabetes, obesity, and neuro-psychiatric conditions. There are currently no in vitro models to study this interaction between the gut and the brain. In this dissertation, we develop an in vitro model of the gut-brain axis utilizing microfluidic devices. First, we established a culture of primary rat vagal afferent neurons and satellite glial cells from adult rats. We systematically compared culture media formulations and culture surface treatments to identify culture conditions amenable for neuronal viability and function. We subsequently expose the neurons to various physiologically-relevant molecules and observe their response via live-cell imaging, as well as extracellular recordings. We then designed and fabricated microfluidic devices to physically separate the neuronal soma and nerve terminals thereby more accurately mimicking their anatomical layout. We studied how different channel geometries influence neurite growth and employed the microfluidically-separated cultures to study retrograde transport of a cholera toxin subunit and neuronal excitability from the nerve terminals. Lastly, we studied the spatiotemporal distribution of capsaicin receptor along the cultured neuron, demonstrating regenerative potential of neurites in culture. We expect that the engineered platform will serve as a versatile research tool to enable various studies involving the role of vagus nerve in the gut- brain axis.

AbstractIn vitro cell culture models are quickly replacing animal models for drug development, mechanistic studies, and precision medicine. Visual methods are the primary means of studying organ-on-a-chip (OoC) models, but are limited to microscopy and immunofluorescent staining protocols. These techniques expose tissues to an adverse environment outside of an incubator or must be prepared with fluorescent proteins, which may affect the underlying cellular processes. In addition, these quantification approaches are often end-point assessments, limiting the number of measurements from a sample. Impedance-based methods allow for continuous monitoring of the electrical properties of tissues that provide insight into biochemical and cellular mechanisms. Transepithelial electrical resistance (TEER) is a useful metric for quantifying the integrity of an epithelial cell layer (e.g., gut epithelium), but lacks the spatial resolution of the microscopic techniques. This thesis reports on the design and experimental validation of a distributed hardware including a voltage-controlled current source (VCCS) for safe current injection, TEER measurement circuitry to sample the impedance across conductive phantoms, and real-time data conversion for monitoring changes in the system. Tomographic concepts will be adapted from electrical impedance tomography (EIT) systems to realize a distributed TEER device capable of continuous, non-invasive spatial imaging of tissues. Multiplexers will spatially expand the TEER measurement circuitry to detect minor changes in impedance by gathering a representative sample of data from the entire chip. The system is validated using conductive and insulating phantoms in saline tanks with varying size and orientation. Finally, EIT image reconstruction techniques are used for converting the raw data to images with high spatial resolution. This platform should be broadly applicable to real-time monitoring of developing in vitro tissue cultures and spatial detection of barrier disruptions, and can be scaled for studies requiring frequency sweeps or higher resolution images.