11. SOFT ROBOTIC#
This week we created soft robotic using different materials.
AIR CHAMBER: BAKED PAPER#
LATEX AND TECHNICAL FABRIC#
I started with a pattern that I had prepared for the second lesson of wearable thinking to create an EMF detector and following a tutorial I had reproduced the pattern with Inkscape.
It was checked with a pencil that the path was all connected and then lasered on baking paper.
Two sheets of paper were cut to create two air chambers.
One created with a technical fabric and a latex fabric glued together with double-sided adhesive paper. One created with vinyl. The vinyl was very easy to iron, the latex scattered a very strong smell and I had to air the room.
The most difficult part in this phase was to separate the two sheets between them and untangle them to spread the pattern with great care and patience given also the fragility of the paper.
Even during cutting it was not easy, it was necessary to continuously pause the lasercutter machine because the pieces of paper fluttered with the air. Fortunately, the pattern has succeeded.
The first inner tube was the one consituited of latex …
In this case when I tried to blow inside the two fabrics, under the air pressure in the narrow and complex track, they separated.
So I decided to detach the two fabrics and put the UHU PVC glue along the path by hand. I had to proceed quickly because the glue does not dry and for small pieces to can slowly lay the latex along the section with the glue. Being a very woven pattern and to avoid that the glue dragged with itself filaments obstructing sections of the air chamber already fine, with the other hand I tried to break the filaments.
The work in my opinion was done correctly. The fabrics were left for at least 12 hours at rest under the pressure of books and various weights.
The latex fabric has somehow transpired the glue because the cover of a book has curled.
The result after having tried again to introduce air blowing from the canula, was the same.
With the air pressure the glued parts come off.
I think the latex is particularly complicated to paste. I think it would be better to find a way to bring it to a temperature such as to melt it lightly with another layer of latex to get a real welding between the parts.
Credit:
Musica: Cold, Jeff
VYNIL#
The same procedure was done with vinyl, but the pattern was modified because the height of thereof was not sufficiently large.
I realized that the external plastic could be removed and would make the vinyl much more flexible.
It is still very difficult to introduce the air along the whole track that is dense and narrow, with only the force of the breath.
AIR CHAMBERS: PLEXIGLASS MOULD AND SILICONE#
It was also necessary for me to experiment the soft robotic with the silicone I always wanted to test but I had never the opportunity to use it until now.
The vinyl was a wonderful surprise and the silicone a joy!
However, given the closing days of the fablab cause festivity in my country, I decided to do quickly on the morning of last Wednesday, a laser mold inspired by the slides of Adriana Cabrera and drawing something very similar but to call to my beloved triangles!
During the study of the form I decided to try to modify the internal grid. Starting from the center the inner tubes are less long than those placed on the end of the mold.
I cut the bases and internal grid for the passage of air with 3/4 mm plexiglass.
I cut the edges with 1 cm plexi.
It was very complicated to trim the edge. I repeated the laser four times, and in checking that the plate was cut, the mold moved slightly creating a rather fine edge with multiple cuts. Its function would have made it anyway but I realized I did not worried about to calculate the thickness of the edge during the development of the model on Inkscape.
The silicone is composed of two equal parts of Ecoflex 00-50 mixed and poured into the molds one with the grid and one for the base.
Both are about 1 cm high and the 3/4 mm difference of the internal grid creates a layer of silicone on one side of 0.6 mm thick.
Only now at the end of the project, I realize that I have reasoned otherwise. The grid should have been made
with a 6 mm thick plexi because this is what creates the passage for the air.
One day they were left to rest and dry and less than 40gr of silicone was added to combine the two parts.
What is left of these 40 gr I poured on the surplus of eco-leather that I had lasercutted in the previous weeks for the modular pattern, I want to understand if I can get a pattern mold.
At this point I realized that I could pour less silicone into the base and add the difference to join the two layers. this would have avoided waste of the product that however was minimal.
The molds, after casting, have lost more product.
To glue the pieces of plexiglass, it was used UHU PVC glue.
The quantity of silicone in the molds of about 15x15 cm in size with a thickness of 1 cm was 100 ml per mold composed of 50 and 50 of ecoflex.
Besides the fact that the inner tubes are too small, I could hypothesize that the added silicone to join the parts, has further blocked the passage of air.
Only the central part swells.
The base I made it thick 1 cm because I was afraid that it could swell even below.
The soft robot is about 2 cm thick for 15 * 15 cm in size and is quite heavy.
Useful links#
Research#
- As for the application of soft robotic remaining in line with the nature for which it is born, the application that comes to mind is the Spider Dress of Anouk Wipprecht.
Certainly it’s not soft, but this is what refers to me.
- The air chambers have been created for many years to create inflatable objects such as mats floating on the water or to create protection like airbags in cars.
A model of clothing item with inside the air chambers that can change the appearance and use that can be done is a model of NuDown Air Insulated Jacket Keeps You Warm that helps you stay as warm as you want outdoors.
Every NuDown garment relies on NuTech technology to enable you to adjust your ideal temperature using air. The more air you pump in, the more air is trapped between yourself and the garment. The inner-air is warmed by your body. You can release air to cool down or even rely on Argon gas to triple the insulation power (thanks to Argon’s higher molecular density).
- I had read of a project of a jacket with a hood that, in the event of a fall from a bicycle or a motorcycle, to repair the head from the impact swelled in a second and wrapped the head, the face and the neck. I did a search but I can not find any online reference.