11. Soft robotics#

Overall a fun week, playing around with extra shaped balloons, silicon molds with fancy air-channels !

Vinyl Inflatables#

We started this week’s assignment by playing around with vinyl sheets and baking paper.. What that means is quite simple : You create an inflatable by cutting twice the same shape in vinyl and once a smaller and thiner version of that shape in baking paper. Here’s a little sketch on how it could look like : And here’s the physical example of it : I also did a second test : ...............

Soft Robotics#

For the soft robotic I just researched some parametric exercises on youtube and hoped to get inspired.

Morph Boxes#

I started with an exercise on how to use Morph boxes on Rhino with Grasshopper. By following the steps I ended up with this :

Grasshopper preview :

Polar Array#

I followed a second video on how to create and use Polar Array. I had the most fun with it and I changed the design and shapes several times just to develop the results a little further. Here’s a sample of the Grasshopper code :

When your satisfied with the result you bake it in Grasshopper and continue the next steps on Rhino. You’ll need to trace an outline around to create a wall for your mold ( extrude the line ). You’ll also need a thin platform to close the mold on the bottom. You can see the different steps/layers here : These steps are to be followed in case you are going to 3D print your mold. A second option would be laser cutting your mold on an acrylic sheet ( min 3mm thick ). For this you need your parametric Polar Array baked. Exported as an illustrator file. And create the 3 needed pieces for the mold : Base - Frame 1 + Polar Array - Frame 2 You can of course change the design of your Grasshopper code at any time. This is why you’ll find above another sample of code, as I made another design.

3D print mold#

The first design I wanted it to be 3D printed. The file was set and I was about to 3D print but the machines at the lab had quite some issues, so I ended up with a few fails at first : Finally, I was able to use Franck’s Ultimaker 2+ and everything went smoothly.

Laser cut mold#

Save your illustrator file as (dxf) and lasercut your acrylic pieces. Assemble the 3 layers by gluing them together ( use clips for a better hold ).

Casting with liquid silicon#

I think casting into the molds was an enjoyable process for me. Here’s how it goes : + get a box of the Ecoflex Silicon mix + put some protection gloves on + mix both liquids 1:1 ratio together + stir until the big bubbles are gone + gently pourring into the molds + let it set and ‘dry’ for 4hrs, or put them in an environment above 24 degrees (exemple : close to a heating element or in the oven)

Gloves on ? Ok Let’s go ! Gently pour the liquid into the mold.

After the drying process,take the the silicon piece out of its mold.

You’ll also need to pierce a whole into the ‘air-canals’ in case you haven’t thought of integrating it into the design..


The 3D printed mold gives you this soft-robotic. In my opinion it ressembles a cymatic design and movement. I thought of the comparison due to my previous work on the assignment of week 3: Circular Fashion

The second design didn’t work as good..

The air blew up the center part but didn’t flew until the end of the ‘tail’.

Still some improvements to be done I guess.


  1. Polar Array Ai

  2. Yellow Inflatable

  3. Polar Array Grasshopper

  4. Polar Array stl