start week 12

docs/assignments/week12.md

 # 12. Soft robotics
 
+<iframe src="https://giphy.com/embed/LMcdsCr6BBLiezff0w" width="480" height="270" frameBorder="0" class="giphy-embed" allowFullScreen></iframe><p><a href="https://giphy.com/gifs/LMcdsCr6BBLiezff0w"></a></p>
 
-This week I worked on defining my final project idea and started to getting used to the documentation process.
+<iframe src="https://giphy.com/embed/ieVDCHlHimBLucYiU3" width="480" height="270" frameBorder="0" class="giphy-embed" allowFullScreen></iframe><p><a href="https://giphy.com/gifs/ieVDCHlHimBLucYiU3">via GIPHY</a></p>
 
-## Research
+<iframe src="https://giphy.com/embed/L4UZpJj941K6EJSsuB" width="480" height="270" frameBorder="0" class="giphy-embed" allowFullScreen></iframe><p><a href="https://giphy.com/gifs/L4UZpJj941K6EJSsuB">via GIPHY</a></p>
 
-"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
+*TPU inflatables and the pouring of the silicon, Loes Bogers, 2019*
 
-> "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
+##Results
 
-## Useful links
+* I made various inflatables using TPU and thermovinyl (one of my favourites shown in the video at the top)
+* Experimented a little with laserwelding instead of baking paper, using TPU
+* I made a silicon 2.5D inflatable with a lasercut mold.
 
-- [Jekyll](http://jekyll.org)
-- [Google](http://google.com)
-- [Markdown](https://en.wikipedia.org/wiki/Markdown)
+##2D molds: thermovinyl inflatables
 
+Our first explorations involved very simple ingredients: thermovinyl, parchment/baking paper and heat. By cutting out airchannels by hand from baking paper, and creating little pockets by welding together two parts of vinyl with heat (using a heat press or iron), we were able to explore some movements and dynamics. Two layers of vinyl are welded together unless there's baking paper between the layers. Where there's baking paper, air can circulate (the baking paper are the air channels). It's not very straightforward to guesstimate what these shapes will do though! So it was good to explore a little first. 
 
-## Code Example
+![](../images/wk12_study.jpg)*Studying simple variations on a shape, Loes Bogers, 2019*
 
-Use the three backticks to separate code.
+<iframe width="560" height="315" src="https://www.youtube.com/embed/zffNF0xYzGc?rel=0&amp;controls=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
-```
-// the setup function runs once when you press reset or power the board
-void setup() {
-  // initialize digital pin LED_BUILTIN as an output.
-  pinMode(LED_BUILTIN, OUTPUT);
-}
+*Using the heatpress, Loes Bogers, 2019*
 
-// the loop function runs over and over again forever
-void loop() {
-  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
-  delay(1000);                       // wait for a second
-  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
-  delay(1000);                       // wait for a second
-}
-```
+**Hints and pointers**
 
+* Add a little nugget to the outside to help you insert a straw or tube later to "actuate" the inflatable
+* Welding lines should be about 5x5 mm at least so make sure to give a 5mm outside margin, and don't make the welding shapes too small.
+* the shiny sides of the vinyl should be on the outsides, the matte side facing in. 
+* The baking paper is sandwiched between.
+* Put this sandwich between two sheets of baking paper and heatpress until the the two sides are welded together. This goes pretty fast, take care not to burn it
+* 140 degrees Celcius is a good start.
+* Peel off one or both sides of the rigid plastic (it will have different results!) 
 
-## Gallery
+<iframe width="560" height="315" src="https://www.youtube.com/embed/-mQh07jm_YA?rel=0&amp;controls=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
-![](../images/sample-photo.jpg)
+**About substrates**
 
-## Video
+I noticed already at this stage that the inflatables behaved very differently when you leave one side of the hard plastic backing on. It helps to control the motion into an upward movement, rather than a cringing, shrinking effect. In this video you can see all samples first with the backing still stuck to the back, and then again without any rigid plastic, just the soft vinyl.
 
-### From Vimeo
+*The tests shown above with and without rigid plastic backing (as a substrate), Loes Bogers, 2019*
 
-<iframe src="https://player.vimeo.com/video/10048961" width="640" height="480" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
-<p><a href="https://vimeo.com/10048961">Sound Waves</a> from <a href="https://vimeo.com/radarboy">George Gally (Radarboy)</a> on <a href="https://vimeo.com">Vimeo</a>.</p>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/WV3oDL-4Bj0?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
-### From Youtube
+*And another few variations that were kind of nice (first with plastic backing, then without), Loes Bogers, 2019*
 
-<iframe width="560" height="315" src="https://www.youtube.com/embed/jjNgJFemlC4" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
+##2D molds: TPU inflatables
 
-## 3D Models
+Bea had some TPU left from another assignment, and found out that this also weld together really well when heat is applied to it! It's a material with a really nice feeling, it's also used as a coating for fake leather materials. 
 
-<div class="sketchfab-embed-wrapper"><iframe width="640" height="480" src="https://sketchfab.com/models/658c8f8a2f3042c3ad7bdedd83f1c915/embed" frameborder="0" allow="autoplay; fullscreen; vr" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe>
+I did a bunch of experiment with that too. Some were really cool with great movements, other less (pweeeep!), see below. In Amsterdam you can buy it at Boeken (a textile shop) in many different colors. 
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/25vC04MQeHI?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+##Designing in Grasshopper
+
+I wanted to practice a bit of grasshopper so I thought: ok maybe I can devise a little study to understand these movements and behaviors better. So I made a design for a rectangle shaped pocket, with simple weld lines at different distances. 
+
+The air holes on the sides of the weld line were too small, the airflow was too restricted in the end, but it was nice to design this in grasshopper and create a lot of variations quickly. I did some tests with baking paper, and also experimented with using the laser as a welding tool. 
+
+![](../images/wk12_grasshopper.jpg)*The grasshopper file, from scratch :D, Loes Bogers, 2019*
+
+![](../images/wk12_rhino.jpg)*Files generated with the Grasshopper file, Loes Bogers, 2019*
+
+**Cutting baking paper**
+
+I also wanted to try cutting the baking paper with laser even though I didn't have the most exciting design. I was wondering if precision in the cutting influenced the movement a lot and I'm pretty sure it does. Small variations in width and placement can really make a difference in the way the inflatable behaves. 
+
+![](../images/wk12_bakingpaperlaser.jpg)
+
+Sadly this design wasn't exactly optimal and I wanted to move on to the silicon inflatable so didn't optimize it. The airchannels on the side of the weld lines were a bit too narrow and restricted the airflow too much. But here's an idea: 
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/oXeSHxbe-78?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+You can see in these four samples they behave very differently depending on the distance between the weld lines, but they're a bit hard to inflate.
+
+**Laserwelding TPU**
+
+Somebody (Bea? Cecilia?) suggested you can also use the heat of the laser itself quite well to weld these plastics together. Interestingggg. Basically it requires a lot of calibrating but the basic premise is that you make sure the laser isn't focused/calibrated. I started by trying some settings with the laser head all the way in. These ended up welding OK, but with very thick and bubbly weldlines, making the airflow even more restricted and making the pockets nearly impossible to inflate. 
+
+![](../images/wk12_laserweldtest_results1.jpg)*Testing and tweaking until finally: some welded results, Loes Bogers, 2019*
+
+**Improved parameters for laserwelding**
+
+After recalibrating I got some nicer results and ended on these parameters. In the video below you can also see that the lines are much cleaner and thinner having the laser a little bit more focused. Lots of tweaking necessary to find a sweet spot though! 
+
+* distance between the two thicker rings of the laser head set halfway, at 22mm distance between them
+* speed: 100
+* power: 18
+* corner power: 10
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/7CyaCYQXOiQ?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+## Lineheating device and thick vacuum bags
+
+This device was left untouched so I thought I'd give it some attention. It's an infitiny roll of vacuum bag, and a line welding device (heats up a single line only). I though what I might do with this and tried to recreate the nice arrow shapes with this one. 
+
+![](../images/wk12_thickfoil_tools.jpg)**
+
+It's less precise to weld so that's not so nice but this material is hella sturdy! You won't puncture or explode this baby easily. 
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/RmrYItkMYR0?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+## 2.5D Molds for silicon inflatables
+
+**Mold material**
+
+Acrylic sheets (give beautiful shine, easy release, easy to lasercut and glue together), glued together with Acrifix or fast contact glue (seconde lijm). 
+
+Glueing large surfaces with glue that dries in seconds is a challenge though!
+
+**Elastomer**
+
+SmoothOn EcoFlex is used as elastomer. Parts mixed in the ratio 1/1, pot life 45 mins, curing time 4 hours.
+
+**Substrate**
+
+Use substrates that are stiffer/different shore than the elastomer, then it doesn't bulge, but it curves away. 
+
+I used a very very stiff substrate on purpose because I wanted to see if it would bulge up whilst staying totally flat. I also made the bottom half pretty thick (= rigid). A bit risky, but worth a shot. My theory might be proven wrong, but then I'll improve using the biosilicon we'll try before the global review. 
+
+##Designing an inflatable and a mold
+
+I used Rhino to design the mold for the inflatable. It consists of designing a treeshape for the airpaths (making sure there's an air hole at an edge). I designed all airpaths to be 6 mm and the space between them at 7 mm. The walls are also 7 mm. I learned to use the *trim* command (finally!) when I learned Rhino has *nothing comparable to the path finder in Illustrator*. Quite disappointing to find out haha! But trim does the job, eventually. Here's a video so I can remember later....
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/pbkiEAYWoJI?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+**Parts list**
+
+The mold consists of two parts that are glued together with a little bit of silicon after: 
+
+1. A base
+1. Air channels in a tree-like shape
+1. An outer frame of 1 or 2 layers high
+
+And the second part of the mold with a piece of textile on top of it is made by constructing a mold of: 
+
+1. A base
+1. The outer frame of 1 or 2 layers high
+1. A (thin) piece of textile to prevent stretching
+
+##Casting the inflatable
+
+* Calculate or measure how much silicon you need. I calculated cm3 with the rough dimensions of the shape, but also checked by pouring water in with the mold sitting on a scale. I ended up with the same numbers: 190 ml for each part of the mold, so 380 ml in total
+* Mix part A and part B *slowly*, add colorant if necessary (I tried getting a marble effect by not mixing in all the pearly white acrylic too well, but ended up with blobs...)
+* Prepare mold with release spray: spray thoroughly, brush into corners, and spray again. 
+* Cover table top with plastic for potential spillage. Pour in a place where you can also let the silicon set without having to move it.
+* Pour silicon in slowly, from one side of the mould ideally. Enjoyyyyyyy!
+
+![](../images/wk12cast_collage.jpg)*1. preparing the mold, 2. Weighing the amount of water that goes into mold (weight in grams = ml = cm3) 3. preparing the silicon, 4. casting and adding textile, Loes Bogers, 2019*
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/mpIX_c6bLeI?rel=0&amp;showinfo=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+**Inflating the inflatable ;)**
+
+
+
+
+###Materials & Tools
+
+* Ecoflex Silicon from SmoothOn (FormX Amsterdam)
+* TPU: the stuff that is used for fake leather (Boeken, Amsterdam)
+* Parchment/baking paper - to create tunnels for airflow
+* Heat - iron, heat press, line heat press 
+* Flex folie (heat transfer t-shirt thermo vinyl)
+
+
+##References and inspiration
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/r8lZBaYGBX8" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+*Tactile Vision by Jiabao Li*
+
+![](../images/wk12_inspi_evolution_mcrae_hess.jpg)*I never get bored of Lucy McRae and Bart Hess' Evolution*
+
+![](../images/wk12_interactivearchitecture.jpg)*   Francois Mangion and Becky Zhang,  Furl: Soft Pneumatic Pavilion, 2014*
+
+![](../images/wk12_instructable.jpg) *Simple but beautiful! Done by Mikey77 at [Instructables](https://www.instructables.com/id/Soft-Robots-Making-Robot-Air-Muscles/)*. 
+
+![](../images/wk12_gummy_actuators.jpg)*Edible soft actuators, YES! Kyle Wagner et.al. via [Soft Robotics Toolkit](https://softroboticstoolkit.com/edible-actuators)*
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/QpnLj-rzjIo" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+*Multi-gait robot at Harvard*
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/zgM-0sPtDWw" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+
+*Instructions for educators to make the soft gripper! Whoaaa that's amazing.Via [Soft Robotics Toolkit](https://softroboticstoolkit.com/resources-for-educators/soft-gripper)*
+
+
+![](https://static.projects.iq.harvard.edu/files/styles/os_files_xlarge/public/sorotoolkit/files/annotated_diagram2.png?m=1404840558&itok=xeuBOjSq)*Open Source Soft Robotics Toolkit Control Board by Wheng Wang et.al. via [Soft Robotics Toolkit](https://softroboticstoolkit.com/book/control-board)*
 
-<p style="font-size: 13px; font-weight: normal; margin: 5px; color: #4A4A4A;">
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