University of Illinois researchers explain how they make their conductive ink on this step-by-step tutorial.

(via Boing Boing)

The Resistor JelTone is an edible toy piano created by NYC Resistor members Ranjit Bhatnagar, Astrida Valigorsky, Mimi Hui and myself for the Jello Mold Competition.

As part of our experiments we realized that jello and fruit, which contain a lot of water, are conductive. Embedded in each jello/fruit key is a sterling silver pin (food safe) connected to an Arduino microcontroller underneath the piano’s base. Below the piano’s case is another sterling silver pin. With this setup, the JelTone can either be played with a metal utensil connected to the Arduino, gloves enhanced with conductive thread, or bare hands by touching both a key and the piano’s case.

If you’d like to make your own, you can get the project files, code and instructions from Thingiverse.

Shown below in its fruit and jello versions. Both JelTones were exhibited on June 25th at the 2011 Solid Sound Festival, Mass MoCA and at the Jello Mold Competition (where it was awarded the creativity prize and was both played and eaten by the exhibit visitors).

LED Dragon Kite by Jie Qi

Jie Qi, from MIT’s High-Low Tech group, posted a couple really nice tutorials on how to combine paper, electronics and smart materials to create beautiful objects.

The LED dragon kite: http://hlt.media.mit.edu/?p=1414
SMA origami crane: http://hlt.media.mit.edu/?p=1448

As the name indicates, electrotextiles are textiles with electrical properties. They’re mostly used for electromagnetic shielding, anti-static and heating purposes, and also for soft circuits: electric circuits or sensors made out of a combination of special fabrics, threads, yarns and electronic components.

:: conductive fabrics
:: conductive threads & yarns
:: special electrotextiles
:: related materials
:: starter kit
:: electrotextiles tutorials by openMaterials
:: learning resources
:: main suppliers

Conductive Fabrics
Fabrics with electrical properties made by blending or coating textiles with copper and/or nickel and/or silver fibers. They’re available in many textures, weaves and combination of materials. Stores such as Plug & Wear, Mindsets and Less EMF sell kits with a sample of each of their conductive fabrics. These samples provide an excellent way to get a hands-on feel for and test the properties of each material in order to find the right one for your project before acquiring it in a larger quantity. There are many types of conductive fabrics and you can find an extensive (though not comprehensive) list on the oM wiki. Here I will only describe some of my favorites.

:: Shieldit Super (iron-on conductive fabric) from Less EMF: a single side conductive fabric made of polyester substrate, nickel and copper. The back side is covered with a non-conductive hot melt adhesive, which activates at 130ºC (266ºF), meaning that it can be ironed on to another fabric, wood, glass or paper. This fabric is a pretty good conductor, easy to apply and thus perfect for making longer connections between components. It can also be cut and sewn like ordinary fabric. 230 g/m², 0.17 mm thick. UL 94V-0 level flame retardant. RoHS Compliant. Gray, 14 inch wide.

:: Electrolycra from Mindsets: looks and feels like ordinary lycra but it’s highly conductive. Its conductivity in one direction depends on how tightly it is stretched - if you pull it the resistance increases and then drops again when stretched even tighter. When cut into a thin strip, the material also warms up when current is passed through it and can thus provide the basis of a heated garment. A 6V battery will cause an appreciable warming effect. Resistivity: 5 ohms per 100mm, increasing to 20 ohms when stretched to 150mm. If the material is turned through 90º and stretched the resistance drops to 2.5 ohms.

:: Knitted Superlight Conductive Fabric from Plug & Wear: an extremely light and transparent conductive fabric, only 190 g per sq.m. It allows air flow and is easy to cut with scissors. It can also be sewn with a standard sewing machine or soldered to. Hand washable. Material: tin copper. Resistivity: 0.1 Ohm per square. Width: 1000 mm (39″), thickness: 1 mm (.039″), max working temperature: 150°C (302°F), weight: 190 g per sq.m.

:: Conductive Aluminum Laminated Fabric from Plug & Wear: a single side conductive (the shiny side) laminate made of aluminum foil and fiberglass reinforced polypropylene tape. It’s easy to cut with scissors and it can be sewn with a standard sewing machine, but it’s very stiff and calling it a fabric is a bit of a stretch. In fact it feels a lot more like a thick aluminum foil which makes it perfect for paper projects. In a recent openMaterials workshop, a group of students cut it into an beautifully intricate shape and used as a touch sensor on the cover of a book. Width: 650 mm (25.5″); thickness: 156 micron; max working temperature: 45°C (113°F); weight: 185 g per sq.m.

:: Velostat: a film made of opaque, volume-conductive, carbon-impregnated polyolefin. The resistivity of velostat decreases when pressured. When sandwiched between two conductive layers, it has a wonderful range for making pressure and bend sensors. Depending on the project, more than one layer of velostat might be necessary, eg. I used 3 layers of velostat to make a pressure sensor that gradually lights up a few strands of EL wire. Thickness: 100 microns; width: 91 cm (36″). Volume resistivity < 500 Ohms/cm. Color: black.

Conductive Threads & Yarns

Conductive threads are made of a combination of either cotton or polyester with alloys of several conductive materials such as silver, copper, tin and nickel. Just as most conductive fabrics, conductive thread is uninsulated making it excellent to connect electronic components to each other or to other electrotextiles. In order to ensure proper connection it should be sewn very tight and with more loops than normally used with regular thread. After some time, conductive thread tends to fray and the stitches to become loose. For this reason I often coat my conductive thread connections with a bit of Wire Glue. Wire glue takes several hours to cure so this coating should only be done after you’re done with all the sewing.

There are several kinds of conductive thread, with significant differences in terms of conductivity/resistivity and fraying, but they are commonly sold in two qualities: 2-ply and 4-ply. The 4-ply contains twice as much metal as the 2-ply, making it more conductive, but it’s also thicker making it harder to thread and sew with. For this reason I usually keep a set of sewing needles with large eyes. The How to Get What You Want and Fashioning Technology websites have some excellent overviews and comparisons of the conductive threads available in the market.

The resistivity of all conductive threads increases drastically with length, making them inappropriate for long connections. For this reason, consider making long connections with ribbons of a good conductive fabric and using the thread only to sew the electronic components to the conductive fabric.

The highly resistive (<1000 Ohm/10cm) silver plated thread offered by Less EMF (cat. #A1226) is good for embroidering fixed or variable resistors.

Conductive yarns are usually made of a combination of polyurethane and inox steel fiber. The resistivity of some yarns increases when the knitted piece is stretched. Again, see How to Get What You Want for great information on conductive yarn.

Special Electrotextiles
:: Textile Perfboard: a fabric base with interlaced rows of thin metal wire.

:: Pressure and Bend Sensitive Fabrics, Tapes and Buttons: made of a layer of insulating knitted or resistive fabric sandwiched between two layers of knitted conductive fabric.

:: Textile Water/Wetness Sensor: detects water by changing its resistance from an open circuit to a few megaohms.

:: EL Wire Tapes: knitted tapes with strands of EL wire weaved into them.

:: Hook and Loop Fastener: similar to velcro but conductive.

Related Materials
:: Wire Glue: even though originally created to replace solder on the connection of electronic components, wire glue is a great material for working with electrotextiles as well. I use it to coat conductive thread knots to prevent them from fraying and also to attach metal snaps to metals that can’t be soldered to.

:: EL Wire: can be basted, woven into or otherwise applied to your soft circuits for illumination.

:: Quantum Tunnelling Composite (QTC): an interesting pressure sensitive material for making textile control pads and keyboards.

:: Metal Sewing Materials: almost all metal sewing supplies, such as snaps and zippers, are conductive and can be used in conjunction with electrotextiles. See oM’s connecting hardware & softwear on soft(er) circuits blog post for some examples.

:: SMD Components: SMD battery holders, LEDs, etc that have flat metal pads are also great for soft circuits. You can solder or wire glue metal snaps or metal rings on these pads to attach them to your circuit.

Starter Kit
I’m often asked what are the first materials one should get to start making soft circuits. Here’s a suggestion for a starter kit:

:: Conductive thread
:: Iron-on conductive fabric or another non-stretch conductive fabric*
:: Stretch conductive fabric*
:: Velostat*
:: Assorted LEDs
:: CR2025 or CR2032 lithium batteries
:: SMD lithium battery holder with flat pads such as this one
:: Non-conductive fabric (felt is my favorite)
:: Sewing supplies: thread, metal snaps, needles with large eyes, needle threader
* Most electrotextiles stores sell conductive fabric sample kits, you can just try one of those instead of buying a larger quantity of the stretch and non-strech conductive fabrics.

Electrotextiles Tutorials by openMaterials
:: Connecting Hardware & Softwear on Soft(er) Circuits
:: Light Up Handshake Glove

Learning Resources
There are many resources for learning how to use electrotextiles. One of the most useful and complete, from a materials and experimentation point of view, is Kobakant’s How to Get What You Want - make sure to check out the sensors and conductive materials sections.

:: Websites w/ Tutorials
Fashioning Technology
How to Get What You Want
Lynne Bruning’s Techniques
Plug & Wear
Plusea
Soft Circuits Saturdays
Sternlab

:: Books w/ Tutorials
Fashion Geek by Diana Eng
Fashionable Technology by Sabine Seymour
Fashioning Technology by Syuzi Pakhchya
Open Softwear by Tony Olsson, David Gaetano, Jonas Odhner, Samson Wiklund
Switch Craft by Alison Lewis

:: Other Interesting Websites
3lectromode
Talk2MyShirt

Main Suppliers
:: Less EMF (USA): conductive fabrics, resistive thread, hook and loop fastener, textile pressure sensitive switches, fabric potentiometer kit

:: Mindsets (formerly MUTR) (UK): conductive fabrics & thread, but make sure to also check out the materials > smart materials section

:: Plug & Wear (Italy): conductive fabrics, textile perfboards, pressure sensitive fabrics, tapes and buttons, textile water/wetness sensor, conductive thread and yarns, EL wire, EL wire tapes

:: Sparkfun (USA): several types of conductive thread

Share your knowledge
If you’d like to contribute content or corrections regarding electrotextiles, please use the comment form below.

>> about the materials 101 series.

MAKING STUFF: Stronger, Smaller Cleaner, Smarter is a four-part PBS television series focusing on materials science:

While reports on “smart materials” or “bionic humans” are familiar enough from TV news and magazine shows, Making Stuff will be the first documentary to provide the basic science behind these and many other technology breakthroughs. Each of the four one-hour public television programs – Stronger, Smaller, Cleaner, and Smarter – will embrace developments in traditional and emerging materials as well as current research in rapidly expanding fields such as nanotechnology and biomaterials. This series will also explore the human stories that helped shape important breakthroughs in the past – the visionary talent, sheer luck, and dogged determination that turned a wild idea into a useful material.
>>Materials Research Society

For more details check out the Materials Research Society and PBS/NOVA websites.

Today it’s possible to print organic field transistors (OFETs), organic light emitting diodes (OLEDs), and other devices using sophisticated laboratory equipment. But why should academics have all the fun? The goal of this project is to design a fabrication process that allows MakerBot owners to print their own electronics using (ideally) inexpensive and easy-to-source materials. In the first phase of the project we are using a RepRap, plotter pens, and research grade materials to create devices. The second phase of the project will focus on exploring new device materials. This is an ongoing project and we are looking for collaborators.

Mr. Kim and Sarik experimented with a variety of conductive materials (silver ink, P3HT, CP1 resin), which they inserted into rapidograph and pigma micron pens. According to the researchers, this is a nine step process:

The project doesn’t yet have a website but, in the DIY spirit of this research, Mr. Kim uploaded the field effect transistor patterns to Thingiverse and made the talk’s slides publicly available at mrkimrobotics.com.

All photos provided by John Sarik and Mr. Kim. John: thank you so much for discussing this fascinating research with me and for sending us the presentation materials.

Interesting article at The Japan Times :)

TSUKUBA, Ibaraki Pref. (Kyodo) Researchers at the National Institute for Materials Science have found that an iron compound becomes superconductive — where electrical resistance disappears in a substance — if it is dipped in wine, sake or beer.

“It is still not known what it is in sake that causes (the phenomenon), but it will provide a clue to the development of new superconductive materials,” said Yoshihiko Takano, leader of the Nano Frontier Materials Group at the institute.

The researchers said they first produced an iron telluride compound, which has a similar structure to a superconductive substance.

It didn’t immediately show signs of superconductivity but then did so after being left on a desk for about a week. Assuming that the change was due to moisture in the air, the researchers experimented with water, ethanol and other substances but couldn’t attain results showing high conductivity.

In March, Takano came up with the idea of trying alcoholic drinks after seeing a wide range of liquors at an institute party.

They found that the compound showed superconductivity after it was immersed for 24 hours in each of six types of liquors, including red wine, white wine, beer and sake, all heated up to 70 degrees. Red wine proved to be most effective.

* “wine glass” image by Scmtb49 - wikimedia commons

I keep thinking that even though we tend to use conductive fabric and other soft circuits materials mostly for wearables and such, there has to be much more to it than that. Ayman’s drumsticks are a great of example of other interesting applications for these materials. He made them for his iPad iSteelPan application, but they’ll work on any capacitive surface.

The iSticks are made out of pure copper polyester taffeta fabric (I bet conductive lycra would work really nicely too), metal rod, string, and cotton pads. Check out Ayman’s instructable and make your own!

(via Alicia Gibb)

Last March I had the opportunity to teach an openMaterials workshop at the very special École Supérieure d’Art d’Aix-en-Provence (France). It was part of a larger event in which the school invited researchers and artists from several fields to lead a one week class for 2nd year art students. The goal was to show them different technologies and materials, which they’d later use on an art project. Besides my smart materials class, there was also an astrobiology workshop by Andy Gracie and a video class by Douglas Stanley.

I was so impressed with the work done by these young students that I can’t resist sharing some photos and descriptions of their projects. These were kindly sent by the very talented artist and teacher France Cadet, who guided the students during the making of their final projects.

Barbed Wire by Morgane Guiard
Morgane wanted to represent barbed wire on her art piece. At first she tried to work with fiber optics: the images on the screen were supposed to drive the might to the fiber optics and make the data travel trough. This structure turned out to be really nice and poetic but also very fragile. She eventually broke it and decided to go with red EL wire. This time she put the display behind the barbed wire and made the EL blink according to the speed of the increasing number of victims shown on the screen (the number of victims barbed wire made during 3 different wars).

Interactive Tapestry by Sarah Martinis and Caroline Geneste
Sarah and Caroline made an interactive tapestry (a bit like “toile de Jouy” with some bone sprinted on it). The patterns were fitted with copper electrodes connected to several capacitive sensors. They were playing 8 different yelling sounds and used a sport electronic hacked device with a few electrodes around the wrist.

EL Dress by Amélie Djellel
Amelie used EL wire and a few handmade conductive fabric sensors to create a touch sensitive seethru dress. Each sensor triggered different strands of EL wire shaped inside the dress and representing forms between the meridians, the veins and the organs. The brightness of the EL changed according to the pressure applied on the sensors.

Color Changing Suit & Dance Performance by Lou Feraud
Lou created a suit sprinkled with UV active (color changing) beads and ink. She then wore it during a dance performance, in which she held some UV LEDs at the tips of each finger on one hand, and bright LEDs on the other hand.

Color Changing Stickers by Mélanie Cartier
Mélanie also used UV active ink to create stickers with the radioactive logo to evoke the memory of the radioactive accident and its invisible repercussions.

Animal by Huna Ruel
Huna used conductive fabric sensors to create a little animal that moves when touched (contracting its head and tail). She then covered it with latex. Unfortunately, once dry the latex shrank a bit and caused the sensors to be on at all times.

During the workshop, Amélie and I made some cards with different types of handmade sensors (using paper, conductive fabric, and velostat) to be kept at the school as a reference. The beautiful drawings and neat handwriting are hers :)

Thank you to all the fun and talented students and their awesome teachers France Cadet, Jean Pierre Mandon and Laurent Costes for a really great week!

Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers.

It involves installing software that collects data from the computer’s accelerometer, which pings the quake-catcher networks’ server if a tremor is detected.

Current model Macintosh and Thinkpad laptops are supported, and the network is making external USB-connected accelerometers available to people who don’t have them built-in to their computers.

Here’s the ‘trigger map‘ from the past week -