Electronic for Chemists_ Syringe Pump
The Syringe Pump eBook is part of the 'Electronics for Chemists' series, which introduces chemists to the practical electronics and automation technologies employed in laboratory instrumentation. Focusing on the design and implementation of low-cost, programmable syringe pumps controlled by an Arduino microcontroller, the book provides theoretical explanations and practical guidance for building and programming such systems.
Its main objective is to show chemists and laboratory researchers how they can design and construct their own experimental equipment using open-source hardware, microcontrollers and simple mechanical systems. Syringe pumps are widely used in chemistry, medicine and microfluidics for precisely and continuously delivering liquids to reactors or experimental systems. However, commercial syringe pumps are often expensive, typically costing between €200 and €5,000. Using open-source designs, 3D-printed parts and widely available electronics, the book shows how such equipment can be produced at a much lower cost: approximately €20–€30 per pump.
The first part of the book explains the principles of syringe pump operation. A syringe pump converts the rotational motion of a motor into linear displacement to push the syringe piston. In the proposed design, a NEMA-17 stepper motor drives a screw-based linear guide mechanism that moves the syringe plunger. To achieve sufficient torque and speed, the motor is combined with planetary gearboxes and mechanical transmission systems. These mechanical components enable precise control of piston displacement, and thus liquid flow rate.
The second part of the book focuses on electronic control using Arduino microcontrollers. Stepper motors cannot be driven directly by the Arduino, so specific driver modules, such as the EasyDriver, or similar H-bridge-based boards, are required. These drivers generate control signals that regulate the stepper motor's direction, speed and number of steps. As the speed of a stepper motor is dependent on the frequency of the control pulses rather than the voltage amplitude, it is necessary for the microcontroller to generate accurate timing signals in order to achieve precise flow control.
The book also presents programming strategies and experimental protocols for operating syringe pumps. Flow rates can be calculated mathematically using the motor step frequency, mechanical displacement per rotation and syringe geometry. The system can be programmed to control multiple pumps simultaneously, or to synchronise them according to experimental designs, such as Design of Experiments (DoE) matrices. This approach enables automated combinatorial chemistry experiments and high-throughput testing.
Additional chapters describe the hardware implementation, including the electronic control box, printed circuit boards (PCBs) and interface components, such as displays and push buttons. The book provides a list of the materials required for assembly, including Arduino Nano boards, EasyDriver motor controllers, stepper motors and LCD displays. It is possible to build a complete system capable of controlling three syringe pumps for roughly €90–€100, making it accessible for educational laboratories and small research groups.
Finally, the e-book contains detailed Arduino code, flowcharts and optimised programming techniques that are designed to operate within the limited memory available on Arduino boards. Examples include programs for controlling single and multiple independent pumps, as well as synchronised pumps for experimental automation.
Overall, this e-book demonstrates how electronics, open-source hardware and microcontroller programming can enable chemists to design bespoke laboratory equipment. By integrating mechanical design, electronics and software, it encourages scientists to engage with the open-hardware movement and develop affordable tools for contemporary chemical research.