Team:XMU-China/Hardware
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To alleviate the biofouling problem of algae bloom in nuclear power plants, we proposed a program, using engineered bacteria to consistently secrete small molecules that can inhibit algae growth towards specific water body. With this intention, we designed a hardware that can float on water, while engineered bacteria is cultivated inside the device. The small molecules secreted by engineered bacteria is then released to the water body through a membrane.The small molecules secreted by engineered bacteria is then released to the water body through a membrane.
Fig. 1. The hardware for P. Globosa.
Meanwhile, for the filter grilles of the cooling water system, which suffer the highest risk of corrosion, we designed another hardware that covers the metal grilles and release nutrients to foster the growth of engineered bacteria anchored on the filter grille, enabling them to secrete protein and then inhibit mussel larvae’s adhesion.
Fig. 2. The hardware for mussel.
P. Globosa part:
Fig. 3. The structure of the hardware fo P. Globosa.
Buoyancy:
The buoyancy is provided by six cubic-shaped float bowls installed on the top of the device. Because the float bowls are replaceable, ballast weight can also be applied to meet the demands when used in different surroundings.
Culture unit:
The main body of this device is an incubator, which is filled with non-liquid nutrient medium and engineered bacteria. One side of this incubator has a square hole for membrane installation. We designed a pipe through the cover into the bottom of the incubator, by which fresh air can be pumped into the culture, providing oxygen and sufficient agitation. The cover also has a small air vent and a big feed inlet.
Membrane:
Our membrane is designed as a sandwich: there are two rigid rough filter boards with a Polyethersulfone filter membrane between them. The filter board can support and protect the membrane from being stuck by large particles. The membrane can block engineered bacteria while allowing small molecules to diffuse out of the incubator.
Motor unit:
There is a small cabin under the incubator to place the air pump powered by an external supply. The weight of this cabin also helps to lower the centroid of the device. What is more, the remaining space of this cabin also makes it easier for us to make further modifications. In our final test, red ink was added to the water to show the function of the air pump.
Mussel part:
Main body:
This device is divided into two cabins: culture cabin and store cabin, which are connected with a syringe controlled by a motor, making sure the culture medium can only be pushed from the store cabin to the culture cabin. The store cabin is connected to airpump by a soft tube, therefore, the inlet air can gradually push the culture fluid into culture cabin. There's also an implemented device for detection of OD600 inside the culture cabin, the detection data can be used to adjust the amount of culture fluid injected each time. The opening of culture cabin has a flexible silicon sealing to fit the rugged surface of grille.
Fig. 4. The workflow of the hardware for mussel.
Two-axis platform:
The device is fixed to a two-axis platform, enabling the treatment of engineered bacteria in different location on the grille.
Data transmission and control system:
The OD600 data collected is transferred by data cable to the computer on the dyke, then the speed and amount of culture liquid injected are determined by computer.
To make our hardware more integrated, we also designed convenient software for Android. Our software has two parts besides some basic functions like log-in function, historical record and so on. First of all, our software can detect OD600 of the environment of the culture room in the software. We divide the grille into twelve areas and number them in sequence. It can provide an intuitive change so that users can stop the nutrient supply system. The data is shown as a chart in order to adjust programs. Part 2 is a mussel counter. By counting the number of mussels on the grille via our program and producing a heatmap, users can find which area is deadly damaged and take pertinent measures. For more helpful information, you can have a look at this video below.