To ensure the solidity, the wall thickness is increased to 0.9mm, which means the print head will print 3 times at one location to help create a tight seal for the bioreactor shell. At the same time, additional reinforce- ment options for the skeleton are also designed for research:

Option (a) is more aesthetically pleasing when using a honeycomb frame structure for reinforcement instead of a triangular frame as in option (b), however the 3D printing process is more complicated and can cause deformation of the shell structure, so option (b) is considered more sta- ble and should be chosen as the main design for the bioreactor:

By integrating the parameters from previous tests, the 3D printing quality of the bioreactor was significantly im- proved and it was possible to verify the ease of fabrication in a single 3D print, especially without the use of support structures, which made it possible to put it into use immediately after 3D printing faster than ever before. The fabrication process used a mid-range 3D printer, which is not highly rated for its quality, but the fabrication process was successful.

After the bioreactor is filled with ingredients, it is sealed. Water is then added through a tube connected to a luer lock. When the reaction is complete, the final product is usually a food, such as yogurt. The new reactor is de- signed to meet the exact usage process as described above, and the new design completely eliminates other compli- cated additional assembly operations and can be used im- mediately after a 3D print. The steps in the usage process are described as follows:
Step 1: Remove the bioreactor from the print bed, cut off the excess ears if applicable. Then check to make sure there is nothing inside the bioreactor.

Step 2: Fill in the ingredients.
Step 3: Seal the bioreactor mouth using one of two methods: tape or heat seal.

Step 4: Pump water into the bioreactor through the luer lock connection.

Step 5: When the reaction is complete, remove the tape or cut the heat-sealed joint for consumption.
For the possibility of reusing as a low gravity cup, the operations are simpler because the author designed the bi- oreactor to also be a low gravity cup, the grooves are shaped to easily lead the liquid from the tank to the cor- ners.
The user only needs to remove the tape or cut off the heat-sealed structure to be able to use it by tilting the cor- ners towards the user's mouth: