Blog Post 2 GRBcelL BioPrinter

By the start of the second week, the gantry pieces of the bioprinter had arrived. A C-beam machine was ordered from Open Builds Store. The full week was spent constructing what would be the base of the machine: the gantry, with all the wiring and software required to operate the machine. While the week blurred together as multiple portions of the gantry were constructed, the first few days, roughly Monday-Wednesday, were spent assembling the X-Y-Z of the gantry alongside the build plate. After the main structure of the machine was built, Professor Deconinck gave us a bulletproof glass box to insert the base system into such that later temperature controls can be added to the mechanical design. Thursday and Friday were spent optimizing speeds and relearning/mastering g-code, the coding language the 3D printer utilizes (g-code is similarly used with many other gantry based systems). When building the printer, the team worked to establish which size of aluminum rail would be optimal for the size of the system’s base plate. Most changes made to the initial design were minute. For circuitry, an Arduino circuit board with a G-Shield was used alongside the software Universal G-Code Sender to run code through the gantry system. In the final model a circuit board known as a Tiny-G will have to be used. This is because while the Arduino worked well for running and testing the gantry, the Arduino only has 3 inputs for X, Y, and Z respectively. The final build of the bioprinter will require the system to have X, Y, and Z movement but will also need a stepper motor for the syringe plunger which adds an additional specific Z movement. The Tiny-G holds 4 inputs compared to the Arduino’s 3, and with these inputs the bioprinter will have more easily controlled motion. By Friday the machine was working without slipping or error, and, midday, the team decided to add limit switches to the machine such that if any arm of the gantry moved to far, the machine would shut itself off. Here we ran into major issues, as a solution to mounting the switches into the aluminum proved to be difficult. While drilling into the beams worked at first on the flat aluminum side beams of the machine, several other steel portions requiring drilling proved to be much stronger and harder to drill. As construction reaches a close, we are making fairly good progress on the bioprinter, but next week will prove to be difficult. Instead of construction, the team will move on to design and prototype systems to create an interchangeable head for a machine that can grip a syringe of any diameter.

– Jonathan Palumbo 6/7/2019