Studio Contrechoc

design & textile & technology entries

Category Archives: cloth and textile


After the knitting sessions at the e-textile summercamp it became obvious that the next thing to develop was a high-tech machine knitted sock.


This sock is made with a KH-940. This hackable electroknit machine is handled fully manually to produce this sock.

The instructions for making this type of sock can be found at:

The sock consists of acrylic yellow and a middle part of conductive wool.

(Nm10/3 conductive yarn
Company: plug and wear
Characteristics: Nm10/3 conductive yarn, 80% polyester 20% stainless steel, light grey, Surface resistance < 100000ohm)

The connection is reinforced by knitting some tours of silver thread at the ends of this strip.

(High Flex 3981 7X1 Silver 14/000
company: Karl Grimm
Characteristic: Very conductive, Solder-able)

ps4 The two types of conductive yarn.

ps3 The silver thread is visible at the start of the strip. This will distribute the current evenly.

The resistance of this strip between the two strands is around 2K Ohm.

This makes this version not yet fit for becoming a foot warming sock. For real warming up a few Watt at least is needed. P = V * I and V = I * R, so a resistance of 2K at a voltage of 10V results in a current of 5mA. This gives 50 mWatt, not enough for warming up. The resistance has to be reduced to 50 Ohm to be able to produce 500mA needed for (a bit of) warming up.

In the next sock another type of conductive thread will be used for the warming up application. This  higher resistance version can be used for signaling (connecting to another conductive strip) or probing the variable resistance when walking.



Victory over the Sun: Paillard 2015 version

This blog post serves as the documentation for the work on display at Paillard 2015.

vos1 vs1


Energy Harvesting, game


Victory over the Sun is a dress which makes it possible to compare the use of several ways of generating energy. In this version the energy of a solar cell can be compared to the energy generated by rotating a hand crank. The amounts of energy for each source is played out to each other on this wearable. Varying circumstances, inside outside, shade, sun gives different results. Playing this game with this wearable is apropriate because it is easily displaced  in different situations, sun, shadow, twilight etc


By playing the gameit becomes clear that it takes a lot of effort to generate an amount of energy to load the supercap, that the sun generates this energy effortlessly when it shines optimally on the solar cell, but that this solar cell is not always (most of the times not at all) in optimal placement when you run around in this dress.


The material used for this dress is pieces of worn out jeans which are still usable. This recycling of material fits the project concept of harvesting energy, that is using energy which is self generated or “left over”. In theory this using worn out material seems nice, but in practice worn out really means the fabric is weak even if you don’t notice it directly. It can be seen at several places that the fabric is very fragile.


For the course of this energy game two verticals rows of bright LED’s are visible at the front of the dress. These lines of LED’s have a double indication. The main indication will an lit LED at the scale of the energy generated, the higher in the row the more energy, the second is another LED which uses the whole scale to indicate progress.

The second expressive behavior occurs after the game, in the discharging mode. The back light up in red and white and these colors fade gradually depending on the discharging rate.



Left to right: hand crank, supercaps, ATtiny85’s, LTC3105

The energy of the Sun is generated by a solar cell. For the hand crank is used a hacked Ljusa of IKEA. The energy of both sources is stored into two seperated 10F supercaps. Two ATtiny85 monitor the voltage in these supercaps. If the voltage in the supercaps stayes above the 5V a winning indication is flashed over the LED’s.

Then the energy is released. The first idea was using an LTC3105 energy harvesting chip to store the energy back into the lipo, charging the lipo.

The second idea was to use the bright Ljusa LED’s inside the back of the silhouet, so creating “a second” expressive behavior.

vs2   vs3

Presentation mode:

For the Paillard exhibition a special presentation mode is made. The electronics has got its own small shade lamps, and the front LED’s will be lit, simulating a game. After the simulated game the back will be lit as if the supercaps discharge.

Artistic Result:

Victory over the Sun is an artistic research result of a Design & Energy harvesting investigation:

Other presentations:

Victory over the Sun was displayed at the Hochschule für Künste in Bremen in 2015.

Victory over the Sun will also be presented at the Willem de Kooning Academy in Rotterdam in octobre 2015.

Former posts about this project:

First and Second sketch version:

Interactive top

Fot the presentation in Bremen we made a simple interactive piece for a possible fundraising auction.

The piece is made of five sided regular shapes. The fabric is lasercutted and the pattern of the the bigger form is coming back in the middle of the shape as a pattern.

From 6 regular five sided shapes a top is constructed in a way we did for 10 years in painting. The difference is that the fabric folds itself around the body, being different from 2D tessalation.

p1 Screen Shot 2015-04-19 at 10.12.19

(see more paintings here:

One of the fabric shapes and some of the paintings in the same configuration as used for the top. Added are two basic shapes one to the right and one to left side. In painting this would have meant that the 2D plane was abandoned. For the textile top this means we get a spatial form slightly coming outwards.

Pattern of the top:

Screen Shot 2015-04-19 at 11.34.05

A picture of a model (Jasna Rokegem) wearing the top:


For interactivite we added three LED’s in the middle of the sides of the central shape. These LED’s are soft glowing, faster or slower depending on the value read by a light sensor exactly at the middle of the protruding shape(LDR).

The nice thing about this top is that you can even hang it on the wall and enjoy its abstract reflections without wearing it yourself 🙂

The script is fairly simple and can be found here:
version 1: glowing led’s:
version 2 (meant for the back): led’s shwoing light variations:
Both scripts can also be found at github:

Needed: ATtiny85, three LED’s, 1 resistor of 2K, 1 LDR, coin cell battery holder, 3V coin cell battery.

2015 NASA App Challenge

Two years ago we participated with friends in the 2013 NASA App Challenge with a wearable. Last year we did a game for the 2014 App Challenge. Now we do another wearable challenge in the 2015 NASA App Challenge:

This is the first time we really try to make “intelligent” garments. We will integrate a neural network in the wearable. This network will “learn” by trying to recognize patterns. This learning will be made visible by changing the shape of the wearable, or even morphing.

The neural network will be small, and the learning capacities will be very limited, but this is a start at “really (somehow) smart” fashion.

Details about this project can be found in this hackpad:

images will follow next week when we try to finish two wearables in one weekend, where normally it takes about a month for a wearable…

But now we come with a group of expert programmers, designers and e-textilers, together with a car full of equipment…

(Making tags for this post … nearly all tags created for this blog are indicated, which means that something will be happening!)

Project page:

Supernova t-shirt with trousers

The t-shirt showing the sequence of observed supernovas of the first 6 month of 2014 was first shown at Paillard in the summer of 2014 during the exhibition Cuvée at Paillard.

Recently trousers were added with all the data which are used engraved with a laser cutter on the fabric of the trousers.

The idea of adding the trouwers is to show the contrast between “raw data” – as text and number items,  and this way of visualising the data of a time sequence on a surface area.

So the supernova observations with coordinates and time and date indication are shown as blinks on the t-shirt and as text on the trousers.

In discussions it appeared that the meaning of the blue/green ellipse on the t-shirt is difficult to understand if you are not a little bit into astronomy. For most people it is possible to look at all the countries of the Earth mapped on one page in an atlas, but the idea that the whole sky is projected into one ellips is not easy. But of course this is the same transformation: the surface of a sphere is projected on a plane into an ellipse. We know that the Universe is “space”, but we percieve it as a sphere, because the distance of the objects in space is so large compared to what we as humans are used to.

This blue green ellipse on the t-shirt is a picture of the Microwave background radiation. This represents the distribution of mass just after the Big Bang (well 350.000 years according to the theories).

On top of this – or rather through this picture – are the observations of stars exploding in the universe. We can see these explosions which are really far away because for some time these stars are as bright as galaxies. So you get a comparison between stars exploding and the ancient mass distribution. Stars like that (very big compared to the our Sun) have a short life time (compared to our Sun). They will end in an explosion after about 10 million years. So these explosions are like leaves falling of a tree, the tree representing the universe. And of course these observations revealed that apparently the Universe is expanding in an accelerating way, indicating that the law of gravity is not the only long distance force…

Back to the wearable, some pictures, textual data on the trousers:

su3 su2 su1

The engraving, done with a laser cutter, is perforating the very light weight fabric, which is not really fabric for trousers, it was chosen more for having a nicely colored surface. (Next time, better fabrics!)


Under the t-shirt is the electronics. Five big led panels are playing the part of exploding stars. The sky is divided into 5 big area’s, for the 5 panels.  The voltage used for the led panels is 12V provided by 3 lipo batteries in series.


The datavisualisation as a time sequence can only bee seen in a movie:





Victory over the Sun – (sketch version)

(see for a more advanced version)

This wearable is part of a research into energy harvesting, which can be found here: (Slow Raspberry pi server!)
The purpose of this wearable is to compare two sources of energy, not just showing a charging wearable.

The title of this project has changed a few times:

  • 1. Not another solar dress
  • 2. Energy battle dress
  • 3. Victory over the Sun

The first title is indicating that this project is not another mobile phone charging wearable. There is a solar panel, but also a hand crank device in the dress. But it is not about charging anything, because charging from a wearable is anyhow not very efficient.

The second title is indicating that the purpose of this wearable is comparing two sources of energy together in a game. The two source compete against each other. Which one will win? The solar energy or the muscular energy?

The third title is a reference to the oper of the Russian avant garde in the Bauhaus time:
Malevich and El Lissitzky made this oper famous, contributing to the stage design and the graphical displays.

There is some sarcasm in this third title, because it is rather impossible to win from the Sun in this game, only at night you have a chance, the solar panel is even charging slowly in normal daylight without direct sunlight.

Appropriately for the material old discarded jeans are chosen. Thus the material is recycled. The wearable is a simple dress with possibilities to add panels and the hacked Ljusa hand crank.

From the parts of jeans which were not totally worn out pieces were cut and these pieces were sewn together. An interesting folding problem popped up which will be described in another post.

Picture of the wearable in progress: (The hacked Ljusa, with the white card board and the red crank will be redesigned and more properly inserted into the wearable of course)

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Wearable made of recycled jeans material.

For the hand crank I have chosen the Ljusa of IKEA, which is a toy generating some power. It stores the power too in a 1.5F supercap. The second source of energy is a solar panel. Added to this is also a 1.5F supercap. With a ATtiny85 and 8 big LED’s – 4 LED’s for each energy source – the winning source can be made visible.

The electronics idea was to show the current Voltage for the two sources in two rows of 4 LED’s. The microcontroller which can just be used is a ATtiny85. Two analog PIN’s and two PIN’s for a multiplexer chip. One PIN is left for one other purpose.

Although the sources are generating energy, there has to be another energy source for the microcontroller at the moment. It would be an nice idea to have the sources (solar and muscle) first generate enough energy for the game to start, but this has to be figured out yet.

The third energy source is a rechargeable lipo battery.
Then there has to be a discharge for the game to restart. This is done using a FRT5 DC5 relay.

The number of difficulties in the electronics were plenty: besides the usual stupid mistakes like connected the LED’s the wrong way there were a few real “Zen master” problems (which means you have to learn something besides correcting stupid mistakes).

The ATtiny85 uses USI instead of SPI, code for this was found at:

Then the implementation of the use of the analog PIN’s proved time consuming. In the end the soution was found in connecting the PIN’s to the GND using a 1M Ohm resistor.

Then the coding of the LED’s, in two groups of 4 inside the bigger group of 8 was proving not straightforward. Apparently the number read using the ADC code is not a “normal” INT number and you cannot use all math available, like subtracting 512 from the value read between 0 and 1024.

The final code can be found here:

Testing pictures of the electronics:
Testing is better down as much as possible outside the wearable. In the end the electronics is on the board and the ATtiny85 had to be removed and placed in the programmer breadboard way too often again, I could have better soldered programming the wires to the board right away…

  • testing first the ATtiny85 and multiplexer on a breadboard
  • testing the LED’s on a piece of jeans
  • the PCB with the supercap, multiplexer, relais and ATtiny85

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Remarks about the PCB:

  • One relais too much, two components right upper side FRT5!
  • At the left side the two energy sources can be connected.
  • The green component is the 1.0F 5.5V supercap
  • The Ljusa has it’s own supercap (storing energy), the solar panel uses the supercap (green thing) on the board.
  • Middle under, ATtiny85, left under hd74ls164p shift register
  • The PCB can be redesigned more efficiently!

Social Wind – first sketch

First images of the Social Wind Design. The idea came from the Warming Dress, see former post

This design called “Social Wind” in a (humorous and friendly) discourse with Warming Dress will become a cooling jacket. The material used for the jacket is fleece, color bright yellow. The basic building shape of the jacket is a trapezoid. Five are used for the conic shape under the middle connection and 5 are used for the top shape. Completing the 3D shape of the jacket are the two shoulder pieces, on top of this jacket shape are two long collors, which run along the neck to the middle, providing stiffness and at the same time pockets for the batteries. The sleeves (inspired by the sleeves used in the Middle Ages which were also used as pockets) are made of two half circles folded open. Theses sleeves fall open to the front and provide space for the small microcontroller (the arduino used for testing the motors will be replaced by a bare bone atmega328 or 5 attiny85 and a central unit with a RF12 transceiver) and the interface for the wearer.

The back has an open strip. Over this strip holders will be attached for 5 small motors that are printed of yellow PLA. The 5 rotors blades on the axis of each motor are leave like.

The motors are so called 3 pahase motors, that means that they can be driven using 3 wires. The script for the motors is fairly simple, the schema presented in this post:

was used. The 5V from the Arduino (in test setup) is probably a little bit too low for these motors, so the script uses a slow start up. For small ventilator blades starting at higher rotation speed wasn’t a problem, but with the bigger blades apparently the moment of inertia was too big. Starting with a slow rotation solved this problem. All the electronics will be gathered in a speical pocket which can be easily removed after discarding the jacket.

Printing the parts between the electronics and the fabric was another detailed process, besides the sewing of the jacket.

The rotor blades are printed as parts, not as a whole shape. The 3D printer used didn’t produce a nice shape if this ventilator was printed as one form. Making 5 blades and sticking these blades in a central axis is more efficient. More details about these 3D prints will be given in another post.


The yellow color of the PLA exactly matched the color of the fleece fabric, the camera is unable to show the exact bright, nearly fluorescent color of the fleece and PLA>

Many details still have to be solved, like the buttons, closing the jacket in front, wiring, designing the interface. There will be 5 ventilators at the back. The ventilator structure in front has to be designed.

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Video’s of Social Wind working:




The mysterious KH-940 weave knit

One of the knitting techniques that was omitted from the list we experimented with uptil now (the skip, patent, nordic, lace and jacquard) was the weave stitch. Experimenting a bit with the weave knit was giving puzzling results. Most of the time this is frustrating, because it means this is going to cost time. On the other hand, if something costs time, it also means that there is something to discover…

I discovered that moving around at either side of the knitting on the knitting machine caused a needle count error, this is fixed now in the software:

(This still is the very basic software. No fancy stuff for an image moving in the Processing sketch when knitting a tour. If the image is too big the underside can even be out of sight. I am wondering about the possibility of having a choice between the different stitches, then give a simple analysis of the image, if this is the right image for this stitch…-possibility to get the inverse -negative – image or the mirror image. Even have an indication if the distribution of the pixels is fit for this stitch.)

The weave stitch is using the entrance of the slider, without being inserted in the first or second thread opening in the middle of the slider:

2014-10-19 09.23.27

The base thread (in the middle opening) has to be very thin and the tension is set to 1-2. The second thread has to be thicker yarn.

Because of the tension setting the produced knitted surface is about half of the image knitted: so starting with the normal dimensions

Captura de pantalla 2014-10-19 a la(s) 10.50.17  The white pixel is showing the thick yarn at the backside.

you get this knitting:

2014-10-19 10.47.11

This is the back of the knitting, that is why the letters in the image are mirrored. For this experiment, we used the MPPT graph again. Apperently, for the weave stitch the pattern of the filling is important. This has to be prepared in Photoshop using the (self defined) preset brushes and patterns.

Then the next step is to enlarge the image height. The graph has to be stretched in the image, to have it normally scaled in the knitting. You cannot use “free transform”, because this would destroy the fill pattern of the surface (although this sometimes gives ideas too). The rescaling has to be done by hand,

Captura de pantalla 2014-10-19 a la(s) 10.48.48

Also we varied the fill pattern of the surface. You already see that it is difficult now to keep the graph in the right shape.

This resulted in knitted weave images were not convincing, the graph appears, but only dim, the weave pattern inside the thin thread is not crisp: See here back (left) and front (right) side:


During knitting the thick yarn was changed three time, to see which would work best. Vertically up the thicker yarn was yellow, middle we used two middle thickness yarns – yellow and light pink- and below the thick plastic pink yarn also used for the pollution scarf.



Here the thicker yellow yarn and the double threads is displayed.

testing further:

Again changing the fill and also making the graph more clear, taking the brush of example 426 from Stitch World Pattern book: x00x00x.

Captura de pantalla 2014-10-19 a la(s) 10.48.59

Also changing the basic thin wire to even thinner (shining blue very thin yarn).

Starting of with the thick plastic pink yarn we wondered about the fact that the knitter was not at all complaining about the thickness of the pink plastic yarn, while the tension was set to 1. Normally for this yarn the tension has to be 9-10. Ok then try even thicker yarn, the bright yellow which we also used for the presentation “Yellow Things”. This was knitted on a knitter with much bigger needles and distance between the needles.

There was no problem knitting this thicker yarn and the image got out very clear now:

2014-10-19 10.33.04  front 2014-10-19 10.28.32 back (on the knitter)

This is the fron side of the image, where the thicker yarn is beautifully overlayered by a mesh of the blue thinny yarn.


2014-10-19 10.33.36 2014-10-19 10.33.41  2014-10-19 10.33.46  2014-10-19 10.33.10,

Details of the fill, the mesh formed by the thin blue yarn, the way the graph is showing in the texture. You can see how the thick thread is catched inside the mesh of the knitting.

This weave pattern begs for more experiments!

Finishing with the cones of the yarn side by side:

2014-10-19 11.31.10

When i looked back i realized the maybe it is not really the thickness but the relative textures of the threads…more experiments are needed.


Weaving the same image with a very thin plastic fiber. The ordinary yellow wool seems to be caught inside an invisible plastic mesh:

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2014-10-19 15.43.47

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some details where the plastic mesh can be seen, and the side with the arched wires.

2014-10-19 15.44.59  the plastic thread used.






Back to knit stitch basics: Comparing stitches

On the one side we already started experiment with real data on the other hand this is still quite a lot of properties to discover about the different stitches. So we went back to basics with a very simple basic image: (Rectangular image – built from black and white squares)


We  made a test knit in different stitches, Nordic, Skip stitch, Patent stitch, lace stitch and Jacquard. The differences were quite amazing. The basic image helped to filter out many interesting characteristics.

Nordic problem case:

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The image above done in Nordic double thread technique (on one bed) becomes a mess, because the very vertical seperation of the big squares. When the image is not under tension anymore it seems to have holes in the structure.

bw_nordic_diagonal  2014-10-15 19.37.17#1

Adding the diagonal is a normal trick in Nordic knitting, the purpose is to reduce the long free threads at the back, and it can fix the problem of the structure falling apart. Of course this reduces the bigger shapes, there are always lines in front.

Also the other stitches are asking for a different translations of this basic image, filling in either the white or the black squares. The fill pattern of course can be varied more.


This image above is used for Jacquard stitch, also using two threads:

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2014-10-15 19.42.55  2014-10-15 19.43.05

The Jacquard knit is dense and feels heavy, like the Middle Ages must have felt 🙂

The patent stitch is working on one wire, with delaying wires to be bound. This can be put to an extreme, where the threads  falls over the needle, which is not done here.

The patent stitch in the square forms a nice hexagon:

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patent stitch backside: hexagons

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patent stitch front side: this is purl and knit alternated. The patent is very stretchy and feels light (compared to the Jacquard knit). Remarkable is also the deformation due to different tensions, hich can be seen in the meandering line between the squares.


used for lace and skip stitch.

The skip stitch in squares show very well that the length is reduced, because the squares are under tension and transformed in the tension of the textile at the knitter:

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2014-10-15 10.16.50 lace under tension

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without tension, there is a big difference between front and back side, whicj could be enhanced or diminished by the choice of the second – cotrast yarn, depending on color and thickness. (The idea of the lace knit is that this second yarn is very thin.)


In the end all the stitches were done in one longer piece of textile: This has the advantage that at least one of the threads – yellow here –  is kept constant for comparing. The effects are also very dependent on the choice of the yarn. But added to that the way to fill in the pattern parts (either black or white in the pixel image) will further influence the outcome. The fill’s chosen for these basics  are only showing the first step. In the fill’s you can go further in creating relief and structure but this pixels structure has to be done very specific to each stitch to avoid knitting disasters.

2014-10-15 20.31.40


Experimental Astronomical knittings

In experimenting with bigger images and different threads new properties of the different stitches (here Jacquard and lace stitch) become clear. For my way of making images: lace stitch has a white background, Jacquard a black fond. Reverse this, and the threads go wild on the knitter.


First an image of the sun’s disk with the sunspots. It can be found on this marvellous site of the Nasa:

Captura de pantalla 2014-10-14 a la(s) 10.20.59 sunspot_jacquard_100

Captura de pantalla 2014-10-14 a la(s) 08.21.33  2014-10-14 10.57.04

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2014-10-14 11.24.25  sunspot_jacquard_half

This was knitted in the Jacquard stitch, 100×100. Clearly the Jacquard is knitted very tight and the sun has become an oval. Photoshopping it to a circle is easy, but the knitting stays the same :-). The right image is reality!



Nice is the so called butterfly effect in solar activity, sunspots. Observed from 1874, you can see the suns activity rise till a maximum around 1960, then gradually decline till the present day.

The picture of the sunspots on the suns latitude appeals because it resembles a leaf.

Captura de pantalla 2014-10-14 a la(s) 10.21.57

sunspot                     2014-10-14 09.42.19 2014-10-14 09.42.29

Knitted in the lace stitch, 100 x 200, the purple thread is at the limit of thickness. The small cone is having some bling thread, invisible in the pictures.

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Another view of the sun’s acitvity can be found here: it shows the solar wind, which is warped because of the rotation of the sun (like a beacon at see). Added to that you can see a blob of extra particles coming out. The view is from above. (This site is loading slowly….)

This observing the sun has a very practical purpose: when the Earth is inside a very active region computers might fail, airplanes falling from the sky, drones going for outer space….

Captura de pantalla 2014-10-14 a la(s) 08.28.24

Originally this is an animated GIF and you can see the dark blue region spiraling outwards.

sun_eruption_100                      2014-10-14 11.23.30 2014-10-14 11.26.34

Knitted in the lace stitch 100 x 100.


Conclusions about these experiments: with increasing number of needles used, clearly the effect of the open stitches are becoming less significant. Also the different stitches produce different tightness, so the pictures cannot serve without mending size and particularly length (number of tours) for all stitches at the same time.