Stirring mechanism – Upon starting the machine, the user can activate the stirring function, which operates through six individual setups, each dedicated to a beaker. Each setup consists of a fan with a magnet glued to its centre and its wires soldered and connected to an external power source. When powered, the fans spin the magnets, creating a magnetic field that attracts and rotates a magnetic stir bar inside each beaker. This synchronised motion stirs the solution continuously as it is dispensed, ensuring complete and consistent mixing. Using magnets and fans, the setup’s simplicity provides efficient, contamination-free stirring, which is crucial for accurate and homogeneous dilutions in lab applications.

Interchangeable pipette and beaker holders – For this project, we used 25 ml beakers and 1 ml pipette tips, making calculations easy with a 1:25 ratio, which simplifies serial dilutions. With this setup, each step reduces the concentration by a predictable factor of 1/25, allowing straightforward scaling and consistent dilution levels with minimal calculation. To add flexibility, we designed interchangeable holders for both the beakers and pipette tips. This means that users can easily swap out holders to fit different sizes of beakers or pipette tips depending on the scale of dilution they need, making the machine adaptable for a variety of dilution ratios and volumes. This modular approach enhances the machine’s usability across different lab setups and dilution requirements.

User Interface – The user interface for the dilution machine runs on Python in the terminal, making it simple and accessible. When the program starts, the user is presented with a few options: “1” to go home, “2” to pipette (with a choice of 1 to 5 repetitions), and “3” to bring E0 up for debugging purposes. If the user selects option “2” for pipetting, the program prompts them to input the number of times they’d like to pipette, allowing flexibility from one to five repetitions. Based on the input, the machine will automatically execute the selected number of pipetting actions, accurately dispensing the liquid in each cycle.