Table of Contents
8. Soft robotics¶
References & Inspirations¶
The innspiration from this week start with two quotes from Acts of Faith. Heart balms for time of monsters by Virginia Vigliar and What is the underworld
I've been looking into root and branch sysytems and similarities within our body, nervous and vascular systems.
- PLEATS: Interior Scenes with Soft and Affective Robots is a research of Eun Young Park that explores the potential of soft robotics
- I found also this page FOAMs: Soft Robotic Artificial Muscles from the Wyss Institute really interesting. It says "Soft robots, similar to living organisms, are made from compliant materials that allow them great flexibility and adaptability for tasks at the human-robot interface and elsewhere".
- I found this PDF Soft robotic actuators which shows different kinds of soft robots and their movement. Here is the abstract: "A soft robotic device includes a flexible body having a width, a length and a thickness, wherein the thickness is at least 1 mm, the flexible body having at least one channel disposed within the flexible body, the channel defined by upper, lower and side walls, wherein at least one wall is strain limiting; and a pressurizing inlet in fluid communication with the at least one channel, the at least one channel positioned and arranged such that the wall opposite the strain limiting wall preferen tially expands when the soft robotic device is pressurized through the inlet.
- Inflatable Pouches for Shape Changing Garments and Accessories was really helpful also if in the future I decided to use a ump and the arduino. Here is the code you could use with a pump.
Research¶
Tools¶
- Vinyl
- Heat press
- Parchment paper
- Scissors
- TPU fabric
- Air pumps
- Alginate
- Gelatine
- hydrogels
- 3D printer
- Filament
- Rhino
- [Arduino IDE](http://class.textile-academy.org)
Heat Press¶
We started with prototyping some inflatables with a heat press, vinyls, parchment paper and TPU.
I tried out different shapes and tested if the air channels would work
What I observed is that the air flow would break the central part as it was quite narrow, but using an air pump would work much better than blowing myself with a straw
Steps¶
- We set a tempreture of 285ºC and a timer of 25 sec.
- To create your inflatable you place a piece of parchment paper, which create your air channels, in between two pieces of heat pressure vinyl.
- The vinyl has a protective film that is always facing outside, so you can remove it once it has been in the heat pressure.
- TPU works the same, you just need to clean it with ethanol to removes residues. However, I had to do a second round of heat pressuring t=with the TPU
- I cut the parchment paper both by hand and using the the laser cutter
Laser cutting settings
I decided to only laser cut the parchment paper as it would had been difficult to place it into the TPU cut in the shape. The room I had would had been really small and just when closing the heat pressure some things might move Some examples!
Some roots I did with illustrator
Idea
This is the idea of beating/pulsing I had in mind while experimenting with these shapes
Alginate¶
We were inspired by Hala Amer's Sodium Alginate Tutorial but we used our own alginate recipe.
* 12 gr alginate
* 40 gr glycerine
* 400 ml water
* 10 ml sodium chloride hydrate
* 100 ml water
* pot
* stove
* spoons
* scale
* moulds
* fabric
* airpump
* tubes
* check valve
* You can find the alginate recipe in my booklet
* Spary the water-sodium chloride solution in the mould and around the frame
* Pour weekly the alginate
* Spary the water-sodium chloride solution on top. Wait a bit so it starts curing
* You can poke the biomaterial, start with a small hole and then use a bigger needle so it is easier to insert the tube. Make sure to not go all the way through but stay in the middle
* Once the tube is inserted, squeeze gently the biomaterial so part of it will protect the hole we made. Spray the water-sodium chloride solution so it cures.
* Then with an air pump, let some air get inside and. It will form a air pocket inside
* With the help of a syringe, pour some of the water-sodium chloride solution through the tube and inside the biomaterial. The walls will start to cure and you'll have your inflatable
My booklet from Biofabricating Material week can be found here
Silicone¶
* Ecoflex Silicone Rubber
* Moulds
* Something to stir
* Jar
* Scale
* Mix part A and B in equal amount (ratio 1:1)
* Stir until completely mixed. You have 45 mins to use it
* Pour slowly the silicone rubber into the moulds. Stay in one plays and let it flow and fill all the spaces. Do top and bottom
* We used the vibration of the air compressor to get rid of the bubbles
* It will take 4 h to be fully cured
* Once cured, you can make a new batch and spread some silicone on the top mould. This will act as a glue: place immediatly the bottom piece and let the cure together
Gelatine¶
Maddie prepared a gelatine solution to test it out with a mould and with two sheets. Check her page!
* 80 gelatine
* 80 gLiceryne
* 500 ml water
* pot
* stove
* spoons
* scale
* moulds
* You can find the glicerine foil recipe in my booklet view
* Fill the moulds with the biomaterials. We used a 3D printed mould and then made 4 squares.
* Let them dry
* You can warm up and melt again the leftover biomaterials, we'kk use it as a glue to create the air channels and join the two parts
* we used an heater to prevent the gelatine form hardening to macu and facilitate the joining process
My booklet from Biofabricating Material week can be found here
Arduino¶
We did not try this in class since we already had many pumps and one already made with the arduino, but on the page mentioned in my inpirations Inflatable Pouches for Shape Changing Garments and Accessories, there are clear instructions on how to use the Arduino and a pump and I'd love to try it with my mould to givew that breathing/pumping feeling
Connection¶
"On the bottom of the pump, one of the terminals should be marked red. This one connects to power, or to a digital pin on an Arduino, and the other terminal connects to ground. The solenoid valve can be hooked up either way. Just connect one wire to ground and the other to power, or a digital pin on an Arduino.
Controlling this with an Arduino is simple. Just digitalWrite the pump pin HIGH to turn it on and blow air, and LOW to turn off. Same for the solenoid: digitalWrite the valve pin HIGH to close and seal the system and LOW to open and let the air out."
Code¶
// Define the digital pin connected to the relay module
const int PUMP_PIN = 13;
void setup() {
// Initialize the digital pin as an output
pinMode(PUMP_PIN, OUTPUT);
// Optional: Initialize serial communication for debugging
Serial.begin(115200);
}
void loop() {
// Turn the pump ON
Serial.println("Turning pump ON");
digitalWrite(PUMP_PIN, HIGH);
delay(3000); // Pump runs for 3 seconds
// Turn the pump OFF
Serial.println("Turning pump OFF");
digitalWrite(PUMP_PIN, LOW);
delay(3000); // Pump is off for 3 seconds
HydroGels¶
Hydrogels are balls used often for plants or agriculture to absorb excess water and release it slowly.
Lærke Lillelund took pictures every 10 min of the first mould
Aslı prepared the 3D mould for us. We made a twisting mould1 and a bending mould[^2]
Steps¶
For this moulds, as they absorbed water, they'd change the shape of the mould curving and acting as a grabber.
- Place a pause in the print to be able to place the hydrogels inside your mould
- Once printed (we had to cure some of the edges) place it in water. We left it for 1h. Make sure to secure it so it stays at the bottom
My mould¶
I decided to start designing my mould in illustrator2 to later edit it in Rhino. Aslı saved me again because I was struggling so much and I could not find clear instruction on the internet on how to create a mould with Rhino.
I also decided to create a mould myself to test the gelatine and maybe other biomaterial. Sadly I had not enough time to print the object.
Here is a view of my top3 and bottom4 parts of the mould.
- Import the pdf file to Rhino
- Offset the line in the inside (3mm) to create the air channels and silicone channel
- Offset the line to the outside (2mm) to create the external walls
Note to self to create solid in Rhino:
- Make sure that "solid" is selected when you extrude
- If you extrude two lines together, it will automatically create a solid
