**Title:** An Open-Source, Programmable Pneumatic Setup for Operation and Automated Control of Single- and Multi-Layer Microfluidic Devices
**Authors:**
Kara Brower 1,4,5,
Robert Puccinelli 2,
Craig J. Markin 3,
Tyler C. Shimko 2,
Scott A. Longwell 1,
Bianca Cruz 6,
Rafael Gomez-Sjoberg 7*,
and Polly M. Fordyce 1,2,4,5,7*
**Affiliations:**
1Department of Bioengineering,
2Department of Genetics,
3Department of Biochemistry,
4Chem-H Institute,
5Stanford Microfluidic Foundry, Stanford University, Stanford CA 94305.
6Department of Physics and Astronomy, California State Polytechnic University Pomona, Pomona CA 91768.
7Chan Zuckerberg Biohub, San Francisco CA 94158.
**Contact email:** Polly Fordyce, Ph.D., pfordyce@stanford.edu
**Abstract**
Microfluidic technologies have been used across diverse disciplines (e.g. high-throughput biological measurement, fluid physics, laboratory fluid manipulation) but widespread adoption has been limited in part due to the lack of openly disseminated resources that enable non-specialist labs to make and operate their own devices. Here, we report the open-source build of a pneumatic setup capable of operating both single and multilayer (Quake-style) microfluidic devices with programmable scripting automation. This setup can operate both simple and complex devices with 48 device valve control inputs and 18 sample inputs, with modular design for easy expansion, at a fraction of the cost of similar commercial solutions. We present a detailed step-by-step guide to building the pneumatic instrumentation, as well as instructions for custom device operation using our software, Geppetto, through an easy-to-use GUI for live on-chip valve actuation and a scripting system for experiment automation. We show robust valve actuation with near real-time software feedback and demonstrate use of the setup for high-throughput biochemical measurements on-chip. This open-source setup will enable specialists and novices alike to run microfluidic devices easily in their own laboratories.
**1. Hardware description**
The open-source pneumatic setup and software (Figure 1) described here can be used for both manual and fully programmable pneumatic control of most PDMS-based microfluidic devices. Our associated software, Geppetto, has both an interactive GUI for manipulating device valves and visualizing their current state (open or closed) as well as command line scripting functionality for automating experiments.
We present 3 build options for the microfluidic pneumatic control system, as listed below. This setup can additionally be expanded for up to 96 control lines and up to 48 flow lines. Control inputs need not correspond to the actual number of valves on the device - only the number of valves needing independent actuation. Typical multilayer microfluidic devices operate with 10 – 15 control lines and 10 – 15 sample lines, even for complicated tasks, but this build can accommodate devices with more or fewer inputs or the need to run multiple devices simultaneously on the same setup.
**2.1. Build Options**
In this paper, we present 3 options for building a microfluidic pneumatic setup:
**Option 1:** A full build for 18 flow lines and 48 individually addressable solenoid valves to drive 48 control lines for fully automated, programmable and remote operation of complex devices or multiple devices
***Option 2:*** An abridged build for 6 flow lines and 8 individually addressable solenoid valves to drive 8 control lines for fully automated, programmable and remote operation of simpler devices
**Option 3:** A low-cost build for manual control of 18 flow lines and 12 control lines
The main text will describe the build for Option 1. The build is modular and can be easily modified to the simpler builds of Options 2 and 3 to reduce time and cost, if only limited or manual control of microfluidic devices is needed.
