Devin Connell's profile

Air-Powered OX513A Dispenser (A-POD) System

Steve Farmer photo
Shown above is the core unit of the A-POD system.

This project is a design intervention to decrease the population of an invasive and harmful species of mosquito, Aedes aegypti. This mosquito carries and spreads the disease, dengue fever, which affects hundreds of millions of lives annually and can be fatal. A company called Oxitec has developed a genetically modified species called Aedes aegypti OX513A. This species is identical to the natural version in every way, except that this species is sterile. The offspring die before they can reach maturity, vastly decreasing the population in any given area of release. Oxitec has performed several field tests of Aedes aegypti OX513A, all of which have shown a staggering drop in population of the mosquito with no negative side effects to any other species. 


From the top left moving clockwise: a female Aedes aegypti drawing blood, Oxitec's headquarters in Oxford, England, a Mobile Rearing Unit, the interior of a MRU. The MRU is used to produce Aedes aegypti OX513A offsite. It requires only water, electricity, and eggs sent from Oxitec headquarters. My design intervention will use the MRU as a producer of Aedes aegypti OX513A.
Images from Oxitec.com
Shown below is the natural Aedes aegypti life cycle without Oxitec's intervention.
The two traits of Aedes aegypti that Oxitec uses to their advantage when producing and releasing Aedes aegypti OX513A.
Shown below is the life cycle of Aedes aegypti OX513A. The dark blue portion of this image is done in the Mobile Rearing Unit, while the light blue is after the male mosquitoes have been released. The process starts with the OX513A gene being inserted into the Aedes aegypti eggs. If the gene is accepted, the immature mosquitoes are raised in a tetracycline environment, this is an antibiotic that acts as an antidote to the sterile gene. When the mosquitoes reach the pupae stage of development, there is enough of a size difference between the two sexes that they can be separated. Again, it is only the males that get released, the female pupae are disposed of. The males are raised to maturity and are released into the wild to mate with females. The females are unable to tell the difference between the regular males and OX513A males, making this system quite effective. The eggs are laid, and without tetracycline, the offspring die before reaching full maturity.
My design intervention will take place in Mumbai, India. They have high numbers of poverty and dengue fever, as well as a lack of education on the subject in many parts. The dark grey band around the globe shows where Aedes aegypti is present. 40% of the world's population lives in the habitable zone. Aedes aegypti originated in Northern Africa, but spread worldwide due to trade and globalization.
The optimal breeding ground for Aedes aegypti is in stagnant water. These graphs show the immense rainfall that Mumbai receives which creates these breeding grounds and inflates the population of Aedes aegypti.
The two images below show Oxitec's current method of release of Aedes aegypti OX513A. They load a truck with the mosquitoes and dump containers of them every block or so, zig zagging through the streets to maximize coverage. Although this system is effective for lowering the population, this method only works for small towns and cities. If brought to a larger scale, this system would have a negative effect on the environment from driving these trucks for hundreds of hours. It is this system that my design intervention aims to improve. I have designed a system of release that uses bicycles to release Aedes aegypti OX513A, instead of trucks. My system would increase effectiveness, efficiency, and is gentler on the environment. The unit I have designed is called the A-POD, Air-Powered OX513A Dispenser. I have also designed an app that coincides with the A-POD to track release of OX513A as well as the cyclists, though the bulk of my effort was in designing the A-POD itself. It should be noted that the breadth of this project in reality would be massive, and this is only an overview of a potential solution.
Images from Oxitec.com
The first step of the system is to designate where the Aedes aegypti OX513A are going to be released within the current zone. To do this, a list of instructions and a map are attached to the top of each A-POD. The red circle at the top of the instructions panel indicates where this A-POD's origin is. A colour slider is also on top of the box, this indicates which cyclist is supposed to move the A-POD. This A-POD is for the orange cyclist, Prakash.
Steve Farmer photo
After the origin and destination of the A-POD have been given, the male OX513A mosquitoes are put into the   A-POD within the Mobile Rearing Unit. To do this, a low powered vacuum is attached to the end of the A-POD opposite the mosquitoes. It is turned on and they are all pulled towards it, but stopped by the screen barrier. Once they're all in the A-POD, the previous container is removed, and the screen door is shut. Next, the vacuum is turned off and removed, and a cap is placed over this opening.
Each night an Oxitec trucks loads all the full A-PODs that are in the MRU. Using the origin indicators at the top of the instruction panel, all the corresponding A-PODs are unloaded at the first Storage Station. The empty APODs at the Storage Station are also loaded into the truck. This process is repeated for all eight of the Storage Stations. The Oxitec truck then returns to the MRU and unloads all the empty A-PODs.
This animation shows a day of routes for one of the six cyclists within the system. Because Prakash is the orange cyclist, he starts at the orange Storage Station. The bike is taken out and he loads on his first A-POD using the colour indicator that corresponds to him. Using the instructions and map on the top of the box, he rides to his first destination, releasing mosquitoes as he moves. Once there, Prakash unloads the empty A-POD, and loads the next one that is orange. This process is repeated five or so times throughout the day until he returns back to the orange Storage Station. Here he unloads the empty A-POD, and puts the bike back in the Storage Station for tomorrow.
This shows the app that will be integrated into the system. The user can live track each bicycle during the day to make sure it has followed its given route. The app can also calculate live statistics such as how many mosquitoes have been released so far today, the average speed of the cyclists, and much more.
Below are two more screenshots from the app that coincides with the A-POD system. The left displays the live feed of all the cyclists within the current zone. Some are finished, some have just started their routes. The right image shows the Storage Station locations from the current zone and the next, the user has the option to move the Storage Stations to the optimal locations. The city of Mumbai will be broken into many zones and be swept across zone by zone to exterminate the Aedes aegypti population.
The animation below shows how the A-POD and bicycle work together to release Aedes aegypti OX513A. As the bike moves forward, the blue arrow shows the air resistance that powers the swinging door to create an opening. At the same time, air passes through the A-POD to allow a flow of release of mosquitoes. 
The following are several photos of the final model of the A-POD.
Steve Farmer photo
Steve Farmer photo
Steve Farmer photo
Because of the inset lid, A-PODs are able to stack for transport. Shown here is the final model with an earlier prototype stacked on top.
Steve Farmer photo
Steve Farmer photo
Thank you.
Air-Powered OX513A Dispenser (A-POD) System
Published:

Air-Powered OX513A Dispenser (A-POD) System

This is a system that optimizes the release of genetically modified mosquitoes to combat dengue fever.

Published: