Hey! I am an architecture student, currently doing research at VUB on the robotic fabrication (using a KUKA Robot) of functionally graded biomaterials. Remarks or hints are always welcome, since I don’t have an extensive knowledge of Biology.
The printability of a mycelium composite will be examined in three different ways. The first method is to print directly a viscous matter which is inoculated with mycelium. Another manner is to create a viscous substrate and let the mycelium pre-grow (during 5 days) before it is printed. As a last option, the possibility to inoculate after it has been printed will be examined. The printability will be in the first place tested by using a piping bag, in order to search for the best viscous matter.
PROTOCOL PREPARATION OF THE FIBRE
- A desired amount of gelling agent is mixed with 100 ml distilled water.
- The mass of the gel to fill a jar is measured.
- The mass of the fibre to fill a jar is measured.
- A humidity of 80% (more or less) is needed for the living organism. Therefore, distilled water needs to be added to the fibres.
- The fibres, distilled water and the gelling agent are mixed in a bowl.
- Everything (filter bags) is autoclaved for 20 minutes at 121°C.
- The mixture needs to rest for 12 - 24 hours, in order to absorb the water and the viscous matter.
- The jar is filled with the desired amount of viscous matter and Trametes Versicolor (10% of the total mass).
- Everything is mixed by a spoon.
- The mixture is compressed by a spoon.
- The samples are placed in an incubator at 26°C.
LOGBOOK (15 - 22 November 2018)
During my first tests, three different % of fibres are compared (80% - 60% - 40%). The fibres were prepared on the 15th. In this case, 200% distilled water was added to the mass of the fibre (see protocol preparation of the fibre), because of the already small chopped fibres and the use of a viscous matter.
WC: chopped wood fibers
Psy: Psyllium Husk Powder
Tv: Trametes Versicolor
Test 1 (inoculated and tested on 19 November 2018): Print directly the viscous matter inoculated with mycelium
During the preparation of the fibres, it became clear that this would be a too dry mixture. This was confirmed by trying to print it with a piping bag, only water was squeezed out.
The created matter was between dry and gelly (more on the dry side), the fibres were able to stick to eachother. Similary to the 80%, only water was squeezed out.
This mixture was gelly. Similar to the tests before, water was squeezed out. On the other hand, small pieces were able to be printed by squeezing the piping bag really hard. This mixture can maybe be optimised, since it is still really difficult to print.
The result of printing, after 8 days (27 November 2018), is shown in the following pictures. It can be concluded that it is growing well. The back side seems still to be moist.
Test 2 (inoculated on 16 November 18, tested on 22 November 18): Pre-growth samples ( +- 6 days)
After 6 days, the growth process can be examined. It seems that both the 80% and 60% are able to grow well. On the other hand, the 40% is only colonized on the top side. It probably can't go through the fibres because of the too much viscous matter.
To test the printability, the matter was again mixed by a spoon and placed in a piping bag.
This mixture was very dry, there came nothing out of the piping bag by squeezing it (even no water). So this mixture can't definitely be used for printing.
This mixture was less dry than the 80%, but still too dry to print. In contrast to the 80%, water was squeezed out.
After being mixed, the matter was still gelly which is good. Unfortunately, the same results as "printing directly" became visible. Water was squeezed out and only small pieces were able to be print (still difficult).
CONCLUSION AND QUESTIONS (15 - 22 November 2018)
Both the 80% and 60% mixtures were thrown away, since they were too dry to be printed. I decided to keep the 40% to see how the growing process continues. Before placing them back in the incubator, the matter was mixed and compressed again by a spoon.
After some extra days of growing (result on 27th), the mixed 40% mixture seemed to have more or less the same results as before. The top side seemed again to be local colonized. On the other hand, it is able to grow (a little bit) through the matter.
40%WC_3%Psy_Tv, mixed again by a spoon
LOGBOOK (21 November 2018 - 27 November 2018)
Since a lot of water was squeezed out during the first tests, only 100% of distilled water was added to the fibres. Only the 60% and 40% of chopped wood fibres were remade (on the 21th), since the 80% was too dry.
During the preparation of the fibres, the structure of the 60% seemed the same as the previous 80%. So it can be assumed that this mixture won't work. On the other hand, the 40% seemed to have a good composition (viscous and not aqueous).
Test 1 (inoculated and tested on 22 November 2018): Print directly the viscous matter inoculated with mycelium
As assumed, the mixture was very dry, there came nothing out of the piping bag by squeezing it (even no water).
The results of this matter were good. By using the piping bag, no water was squeezed out and the printing itself went easier. But, the structure still needs to be optimised, since only small pieces were able to be print (no continuous piece of material, pieces were falling apart).
The result, after 5 days (27 November 2018):
Test 2 (inoculated on 22 November 18, tested on 27 November 18): Pre-growth samples ( +- 5 days)
The mixture seemed to grow well. As can be seen on the picture, the matter is very dry when mixed again by a spoon, nothing came out of the piping bag (even no water). It was even not possible to push the material till the end of the piping bag. So this matter can't be used to print.
Compared to the previous mixture of 40% fibres (200% distilled water), this one seemed to grow better. On the other hand, the matter wasn't viscous anymore, only water was squeezed out when using the piping bag. It can be concluded that this composition can be used to print directly (still needs optimisations) but not after it is being pre-growth.
CONCLUSION AND QUESTIONS (21 - 27 November 2018)
The 60% mixture can't be used to print (directly or pre-grow), since it is too dry. The 40% can't be used to print after it is being pre-growth. On the other hand, the mixture has good results to print directly. Optimisations are still needed in order to print in a fluent way.
Master Thesis by Ichelle Nieberding, Under supervision of Elise Elsacker, Prof. Lars De Laet and Prof. Eveline Peeters / Vrije Universiteit Brussel / Department of Architectural Engineering and Bioengineering Sciences.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.