This is the design of the servo driven stop cock valve that works with the stepper motor driven syringe pump. These valves can be positioned into 4 different ways. Input is where fluid is drawn from the reagent reservoir (like a pressure compensation vessel, more details here) to the syringe. Output is where the fluid is pushed from the syringe pump towards the dispensers. Bypass is where the fluid paths are closed. Closed is where the syringe pump to the dispenser is closed but the flow path from the reagent reservoir to the dispenser is open. Each of these flow paths are used for operation liquid handling processes.

The system includes:
    1. Servo
    2. Polypropylene 3-way stop cock valve
    3. 5 volt power supply
    4. Tubing and luer-lock fittings
    5. Optional: Arduino based control electronics (command line interface software can work with any computer)
    6. Optional: Raspberry Pi internet-of-thing (IOT) controller running web based GUI and MQTT client