Team:HZAU-China/Hardware
Hardware
Overview
In order to put our Tooth Fairy into practical use, we have produced four matching products. These include: a "Teeth braces" to accommodate the Tooth Fairy, M9 agaroses medium and freeze-drying bacterial powder to easily use, a "Box" to active fluorescent protein, and an "App" to determine and report teeth bacterial infection situation based on color. These four products will encompass a complete set of usage processes.
Design
Teeth braces
Our "Teeth braces" can completely wrap the user's teeth, and a cavity is designed on the occlusal surface of the braces for adding engineered bacteria (Figure 1).
Figure 1. A Teeth braces in early generation. "Teeth braces" in this picture is handmade. In the future we will use the below process to produce braces. B Schematic of cavity.
In real production process, we will first conduct a 3D scan of users' teeth. After importing the data into 3D software, we will enlarge the model data of the occlusal surface, so that the braces can be made to cover users' teeth and form a cavity. The data of non-occlusal surface will remain unchanged to ensure the braces fit users' non-occlusal surface and prevent the fall of it.
The thickness of the braces we designed is about 0.5mm to 0.75mm. Ordinary 3D printers cannot meet our requirements to print such a highly precise and thin-walled product. There is also a problem of deformation caused by shrinkage of the printed product after forming. So, we plan to use UV-curing 3D printers which can solve these problems. In terms of the choice of materials, we adopted TPU (Thermoplastic polyurethanes) material, it has the excellences of high tension, high strength, toughness, resistance to aging properties, and harmlessness to the human body.
Medium & bacterial powder
In future use, the products will also include M9 agaroses medium and freeze-drying bacterial powder (Figure2) protocol see protocol page. When using the braces, users should heat the medium until it melts, then pour it into the cavity of the braces, wait for the solidification of the medium, and then sprinkle with freeze-dried bacterial powder evenly. When the users put on the braces, the nutrients in the medium and the oral temperature are perfect conditions for bacterial anabiosis, and after the Tooth Fairy woke up, she will be ready to perform the task of repairing enamel.
After the users check for bacterial infection levels the next morning, they just need to wash the braces so that they can put them into cyclic use. Due to the designed suicide module in our project, there is no need to worry about safety problems caused by engineered bacterial infection. In the future practical use, the safety of engineered bacteria will be improved greatly.
Figure 2. The M9 agaroses medium and freeze-drying bacterial powder. Due to the limited experimental time the M9 agaroses medium and freeze-drying bacterial powder are just conceptual products.
Box
In addition to repairing enamel, our Tooth Fairy also has the ability to treat Streptococcus mutans infection problem, and in order to report the condition of teeth to users, the Tooth Fairy produces fluorescent proteins as a signal. In order to activate the fluorescence of fluorescent proteins, we designed the hardware "Box" (Figure 3), which has a hole in the lid for taking photos, enough space for braces inside, and a built-in excitation light for activating fluorescent proteins. After one night's use, users can put the braces in the "Box", turn on the light switch, put the phone on the box to take photos, and finally upload the photos into the "App" for analyzing. The hardware can ensure that all photos taken by users are in the same external environment, avoiding the impact of external light on "App" recognition.
App
Because our project reports module using two kinds of fluorescent proteins, when the fluorescent proteins express together, the mixed color is not easy to allow users to accurately assess their teeth condition, and the subjective judgment of everyone is not consistent, so we program an "App" to analyze the fluorescent color (Figure 4). Users only need to import their photos into the "App", the "App" can automatically identify the fluorescent color, and report the condition of bacterial infection to users.
Usage process
Before users go to bed, they can add culture medium and freeze-drying bacterial powder into the "Teeth braces", and then go to bed with the braces. When the users wake up the next day, they can take off their braces, put them into the "Box" and then open the switch to active fluorescent proteins, which were produced by the Tooth Fairy. Finally, users can take photos of the braces in the "Box" and import the photos into the "App" for analyzing. The "App" will report the condition of teeth bacterial infection.
Notes
1. "Teeth braces" in this picture is handmade. In the future we will use the below process to produce braces.
2. Due to the less experimental time the M9 agaroses medium and freeze-drying bacterial powder are just conceptual products.
