An open source for multiplexed, stable and transient flows to advance life sciences using microfluidic control automation

Multiplexed fluid control is a demanding task in various studies in life sciences and bioengineering. Herein, we present open-source microfluidic sequence automation (MiSA) that offers flexible and multiplexed fluid control for various applications, providing constant flow via pressure-based feedback control with 10-plex capability and pulsed flow on the order of 100 ms. MiSA was self-contained, including a pressure source, and employed an Arduino Micro to integrate ten solenoid valves, an off-the-shelf pressure regulator, and a flow sensor to balance cost and reliability. To offer stable microflow control, especially at a low flow rate under low flow resistance, MiSA used a potentiometer that tuned the range of the pressure control by leveraging the full 8-bit output from the Arduino Micro applied to the pressure regulator. We demonstrated the practical use of MiSA for multiplexed chemical reactions by performing hybridization-based in situ sequencing. To demonstrate the flexibility of MiSA, we showed the extensions of our system for two pressure regulations under open-loop control in flow rate by revealing three independent applications: droplet generation, microfluidic spinning of spider silk fiber, and atomization of protein solution. We envision that this open source will offer resources for researchers to explore microfluidic applications rapidly with an affordable investment.