An Automated Microfluidic Delivery System for Sustaining Brain Organoids

As NASA prepares for extended human space exploration beyond low Earth orbit (BLEO) with the Artemis III mission and future crewed missions to Mars, understanding the biological effects of prolonged space travel on humans is essential. The Radiation Biophysics Lab at NASA Ames Research Center employs brain organoids derived from human stem cells to study these effects, specifically solar radiation and microgravity. Organoids are cell cultures that replicate the structure and function of organs, sustained by nutrient-rich fluid called Neural Induction Medium (NIM). Currently, sustaining these organoids requires frequent manual intervention, including repeated replenishment and preheating of NIM fluid, limiting the study’s ability to become fully automated for future iterations. Our project contributes to this research by developing an automated fluid delivery and heating system that nurtures brain organoids in microfluidic cards. The system uses a stepper motor actuator pump to push air into a cold reservoir containing NIM. The resulting pressure drives the NIM from the cold reservoir kept at 1-8ºC located in a refrigerator, fitted with tubing entry and exit ports, into a resin-printed microfluidic card. The NIM is gradually heated from 1–8°C to 37°C (±0.5°C) as it reaches the organoid wells by a resistive silicone heater pad that rests underneath the microfluidic card. The temperature is regulated by a feedback loop to ensure precise temperature control, allowing the NIM to reach and stay at human body temperature. After exiting the microfluidic card, the NIM is directed to a waste reservoir. NIM delivery is required to have a flow rate between 15–500 μL/hr. The system was validated in a 24-hour experiment, achieving a stable flow rate in the required range and maintaining temperature at 37°C (±0.5°C). This automation improves experimental efficiency and reliability, making long-term biological studies in space more feasible. Additionally, collaboration with the NASA Telepathy team enabled the integration of pH and temperature monitoring for comprehensive environmental control. Future steps include conducting longer test runs to gather more data and improving the system setup for better performance. This involves developing a pressure-driven pump with multiple interface channels, or ‘splitters,’ to allow for concurrent testing of multiple stacked microfluidic cards. Refinements will focus on creating a more compact baseplate, refining the heating control loop, moving our electrical wiring from breadboard to custom PCB, and optimizing the cooling mechanism for NIM—potentially replacing the mini-fridge with a more compact solution such as a water jacket.