Our original idea was to create genetically engineered cells that would not require any electrical or mechanical input to keep cells suspended in a culture. However, we soon realised we would be facing homogeneity issues due to heat and nutrient transfer if we did not come up with a design that could continuously re-suspend our cells inside our lightbulb. So we invented that too. We created a rotor that gently moves the cell cultures around such that they are always in correct suspension and equilibrium. We also considered the high energy strain of the cells due to luminescence production, temporary/limited food source, robustness/safety/biocontainment, permeability to oxygen (gas exchange) and human perception.

We developed mathematical models to determine the optimal dimensions of the light bulb as well as the quantities of each microorganism required to provide the maximum amount of luminescence possible (160W). The circular structure of the LIT bulb maximizes the exposure of Cyanobacteria to sunlight. We introduced a pump to ensure the cells remain suspended and the cell culture is homogeneously distributed throughout the LIT bulb. We also added a three-way manual valve to allow for the easy replacement of media once every 12 months. We will add a filter to the valve to allow media to be replaced without removing the cell culture. To validate the robustness of our product we would conduct a series of experiments to optimise the shape and components of the LIT bulb using the data we have obtained from our OptoFlux design model. The LIT bulb has been designed such that it fits inside the conventional streetlamps in London.

The final LIT Bulb design aims to provide a long-term stable light source. We plan to engineer E. coli cells to bioluminesce only at night time to minimise the energy strain of bioluminescence production, and to engineer cyanobacteria to perform their natural photosynthesis but secrete the glucose product to feed the E. coli cells for their long-term survival. The oxygenic photosynthesis by the Cyanobacteria will simultaneously reduce the amount of carbon dioxide in the atmosphere. Our aim is to create organisms that can only reproduce and survive under artificial conditions. To do this, we envision running our own experiments which will be aimed at evaluating which bacterial strains grow solely in the presence of very low levels of specific gases, namely Oxygen gas. We would also test our LIT bulb under extreme environmental conditions to ensure that luminescence would be produced by our bacteria under the harshest of environments.