Pigment extraction

Our final product from the cells will be the pigments we require to make ink, but before we can use them we must extract them from the cells> The way we will be extracting the pigment is via organic extraction. We will first centrifuge the cells and liquid LB broth media in order to get just the cells and pigment in the pellet. This will allow us to pour off the supernatant which will be the media to get the cells to work with. We will then add the solvent for the organic extraction and depending on the pigment it will be either acetone or methanol. This will lyse the cells as well as have our pigment dissolved in it. We will then homogenize the mixture in order to destroy all of the rest of the cell membranes and any living cells. This homogenized solution will then be put through a series of filters in order to get out the larger proteins and all of the parts of the cells, this will leave us with pigment and the solvent and all that is left is the evaporation of the solvent.

Fig. 1 This image shows the process of our pigment extraction from the cells starting with live cells with pigment inside of them and ending with our pigment.

Ink production

Now that we have our pigment isolated from the cells that produced it, we need to add it to the other components of ink to allow us to put it in a pen. The Three main components of ink are the Resin the Solvent and what we have made, the colorant and in our case pigment. For our resin and solvent, we have selected gum arabic and acetone as our research revealed that these are some common materials that will perform as necessary. The resin must evenly spread the colorant throughout the ink and across the substrate. The solvent contains the other parts and allows for the ink to be stored in liquid form as well and it will evaporate rapidly as they are volatile and will leave the resin and solvent on the substrate. If we were to ever apply our pigments to printer ink we would need to very carefully control the proportions of pigments resin and solvent as printer require a specific and controlled viscosity in order to correctly use the ink.

Proof of Concept

For our proof of concept at the Boston Jamboree, we intend to bring fountain pens that we have filled with ink made with the pigments that we are using. We have ordered the pigments that will be our final product and have made ink out of them. This allows us to do some quality control testing on the ink as well as removes any Jamboree. The creation of our ink for use in fountain pens does not need to be as precise in terms of viscosity and proportions as it would need to be for printers. This is because there are no mechanical or moving parts or moving of ink within the pen, all we need is for the ink to be able to come out while keeping the amount of solvent as low as possible to prevent bleeding of the ink. This allows us to just attempt a few proportions we have found in the literature for use in the pens.

Quality control of ink