Team:Rotterdam HR/Design

iGEM Rotterdam HR 2019

Design

Introduction

More than 40% of the plastics we are producing, are only used once. Even biodegradable plastics are not a good alternative. In the cold, low-oxygen environment of a garbage dump or in cold ocean water, such a plastic does not appear to break down. Because of these reasons we started creating a health risk detection kit, that will be biodegradable.

Design


Figure 1: First idea sketches.


Together with other design students, we created a different kind of ideas for the HDRK. With those sketches, we decided to make 3 different concepts.




Figure 2: Concept 1.





Figure 3: Concept 2.





Figure 4: Concept 3.


Concept 3, the test with display, got shot down. The main reason, it would be a bit too expensive if the user throw the whole product away after every single use. For the two main designs, the team suggested a combination of the two: the design of the analog test and the material of the decomposable test. With this feedback we created the first HRDK.




Figure 5: First poster of HRDK and our stellation at Future Flux Festival.

http://www.futurefluxfestival.nl/industry-day/health-risk-detection-kit-hrd/

At the Future Flux, we presented our first idea to get some feedback, to develop our product and process. The most important points were: how many checks, size of the test and how to use the HRDK.


Figure 6: Difference in size of the first HRDK and the last HRDK.

After we have received all the feedback, we started to make a new design. In this design (8), we could intergrade four detection systems. Two extra control points are required for reliability: one positive and one negative control. The channels must also be of the same length. For capillary working, we have to make the channels smaller.


Figure 7: First engineering.

We changed the model with these requirements. Only after we showed this test to Jos (instructor) he suggested making 4 more viewpoints to see the substrate.



Figure 8: Second engineering.










Figure 9: Third engineering.







Figure 10: System with the 3 wells per target.

For each target there are 3 wells, on each well we will have our system dried on paper. One well is for the negative control (yellow). In this well we will have our system without the split-TEV proteins, because without TEV, the inhibitor will not be cleaved off from β-Lactamase. So, there will be no color change.

The second well is for our positive control (red). In this well we will have our system, but instead of the split-TEV proteins, there will be a functional TEV. In this case it shouldn't matter if the target is present, because TEV will cleave of the inhibitor from β-Lactamase anyway.

The last well is for our sample (yellow or red). In this well will be our system as described on the description page.

App

The app would be a tool to understand the tests and to save the results. With this app you can see the first steps when tested positive. But what if you want to use the test, and you don’t have a phone? In the package leaflet, an explanation can be given about how the test works and how you can read it.

How to see you tested positive or negative? You are going to test 4 different kinds (for example) of E.Coli infections.



Figure 11: Future concept app and results by normal tests.

Material research

We tested 3 sorts of papers in stagnant water: paper, toilet paper, and egg-box cardboard. After 3 months only the toilet paper and egg box cardboard have changed. The toilet paper has been turned in tiny fibers.





Figure 12: Test degradability and test degradability after 3 months.



Figure 13: Difference in paper fibers after 5 minutes stirring the water.

The coating will be made of (seaweed/plants) sodium alginate, a gel membrane made from brown algae.



Figure 14: Sodium alginate and coating material.

Production

First, we made pulp(figure 15) out of 5 different papers: toilet paper, paper towel, egg boxes cardboard, paper, and recycled toilet paper. We also tested how the papers break down in water. After making the pulp I 3D printed a press mold. The paper has been pressed in the molds(figure 16) and afterward dried by fohn. This way we tested the strength of the papers.



Figure 15: Paper pulp.





Figure 16: Pressing the pulp in the mold and dried tests.

First, we tried to make a small one, after these tests we created the last version of the HRDK.



Figure 17: Final version of the HRDK.