Introduction: Animated Textiles
"....imagine looking down on yourself and seeing a surface structure that is rich in detail, composed of manifold fragments, and infinite elements, each unit with a purpose, and a function... Now, imagine it all coming to life as you move, ...., gently, slowly, responding to your body language."
This is the aesthetic concept of "Articulated Dress"- a garment designed to move and shape itself sculpturally, recognising your body-movement, and translating it into an a slow, sensual textile movement.
The interaction of the dress works by incorporated accelorometres and gyroscopes, recognising certain body gestures, and translating them into an electric impulse, triggering the shrinkage of fine Shaped Memory Alloy yarns (aka Muscle Wire), that are stitched onto the backside of fine plissé fabrics, which are causing a transformation in the visible textile surface.
In this Instructable I explain how the to prepare the Shape Memory yarns and build a simple circuit with them, so that you can attach it to any kind of fabric, to make it become alive by powering it:)
Why doing so? Think about visions like the self lacing shoe from "Back to the Future" for example, or recent technologies like "Project Jacquard". This Instructable can be seen like a guide to the making of a model on ideas like in-woven technologies and smart, responsive textiles/surfaces in general.
Step 1: What You Need
What you need?
- Muscle Wire / Shape Memory Alloy (SMA) / Nitinol
- heat gun
- machine oil
- thin silicone tubing for insulation
- conductor wire (best: single conductor)
- a button
- threaded rod or screws, size M3
- 4 screw-nuts, size M3
- a bowl of cold water
- a pair of pliers
- a pair of cutting pliers
- a pair of crimping pliers
- shrinking tube (to insulate the connections)
- nylon thread
- needles, scissors, pins
- power source / min. 9V battery
+ a soldering iron > to connect button + battery connections)
+ very basic soldering skills
Step 2: Choosing the Right Kind of Fabric
Choosing the right kind of fabric is one of the most important aspects to make this project a successful experience and “magical” one.
For this the materiality and weight of the fabric are important factors, and depending on what you choose, the movement will feel more or less natural. Best is to go with fabrics that already “suggest “ movement through their intrinsic materiality. So something fluid, light or springy is a good choice. Heavy or rigid fabrics, like wool-felt or denim won’t work so well.
I have been working a lot with plissé fabrics. These have movement and expansion already “built-in”, in their surface structure, which makes it feel natural, and therefore more magical when they start moving by themselves.
Step 3: Attaching the Wire to the Form
To get started, prepare a random amount of Muscle Wire, to do some actuation tests in combination with the fabric of your choice. This way, you can try different wire placements, until a natural and interesting movement is found.
To begin with:
- take the screw or threaded rod and two nuts. Screw the first one up to the screw head or about 5cm into the rod.
- take the Muscle Wire and wind it a couple of times around the screw/rod, while holding firmly onto the short end
> you have to be careful and hold well onto the wire; it is springy and has a tendency to unravel itself easily
- fix the wire end by inserting the other nut and squeeze the wire well it in between the two nuts.
To tie them firmly you can use the pliers. Please note: the wire has to be fixed very well, as it will try to leave the rod by straightening itself out when you start to heat it (Step 4)
- wind the rest of the Muscle wire onto the screw/rod, until 1cm before the end of it.
- insert another nut and hold well onto the already wound up end
- bring the wire on the other side of the nut and wind it another couple of times around the screw/wire
- insert the fourth nut and squeeze the wire in between the two. Use the pliers to tighten the nuts firmly.
NOTE: 3,5 cm of wound up SMA wire (on a thread size M3), will be, when stretched out approx. 55 cm long.
For the first test, cut this piece in two (after baking), and work pieces that are not longer than 20-25 cm
Step 4: Making the Muscle Wire Remember the Form
Now you can "bake" the muscle wire to give it a shape memory.
For this, use the heat gun and some pliers to hold it. (> make sure the handle is insulated, bare metal will heat up lot. Its actually also a good idea to use protection gloves! )
- Heat the wire on the rod/screw at 300° for 10min (> check the heat levels on your particular heating gun)
> hold the screw/rod right infant of the heating gun, thats where the temperature indications apply.
- Drop it after 10 min into the bowl with cool water, to cool it down rapidly > it will sizzle promptly
After this step, let the rod/screw cool down for a couple of minutes, then loosen the first to nuts, and unravel the wire carefully from the thread. Dont stretch it to much and try not to bend it, but keep its shape and direction intact
If you want you can try to see if it remembers it shape at this point. To do so attach the wire via come crocodile clamps briefly to a battery, to get it to pull itself together > Be careful to power it carefully and not to heat it up too much + try not to let it touch itself / get in contact with itself > this causes high voltage on a short length, leading to too much heat, which will burn out the shape memory function in the overheated area.
Step 5: Insulating the Muscle Wire
After testing it, extend the set Shape Memory Wire again
- apply a thin layer of machine oil onto its surface > The oil helps to slide the wire easier into to silicone tube.
- stretch one end as straight as possible and slide the wire, inch by inch, into the silicon tube
> this is a little bit fiddly and requires some patience.
Also; try to do it carefully, the silicone tubing can rip, when pulled too harsh or cut or pinched by the point wire
The function of the silicone tube is, to heat-insulate the wire, so it won't overheat or burn out when it gets in contact with itself while being powered,
Step 6: Connecting the Muscle to a Conductor Wire
To be able to extend the circuit and connect the SMA to a button & power source, you need to attach the SMA yarn first conductor wire. Best is a single conductor (just to lower the weight of electronic parts)
- Prepare your materials: conductor wire, SMA yarn, crimps, crimping plier, 2 pieces of shrinking tube (lengths: long enough to cover the crimp + approx. 5 mm additional on each side)
- take ca 2 cm of the insulation off the conductor wire and twist it firmly
- place s crimp on the bare end conductor wire and a piece of shrinking tube, somewhere onto it.
- push ca. 1cm of the silicone insulation, back onto the SMA wire and stick the bare SMA wire, from the other side into the crimp.
- Squeeze the crimp the crimping pliers, to connect the SMA with the conductor wire.
-Slide the Shrinking tube onto the crimp and centre it
- shrink it onto the crimp and the ends where the SMA and conductor wire meet the crimp, by using a lighter or the heat gut. Make sure it is all well attached and firmly connected, so it doesn't come loose while powering.
DONT BE SURPRISED; the SMA wire will start moving when you shrink the tube = it is reacting to heat!
- always crimp well and catch the crimp as well as the first mm of wire and sma with the shriking tube. => Due to the force of the muscle wire it easily comes loose afer a few (tours)
Step 7: Closing the Circuit With a Button + 9V Battery
In order to control to control when the wire is being powered; so when it "contracts" and "relaxes", it is useful, actually important to connect it to a button > Otherwise the wire will be pulled together into a firm spring, as it would continuously be heated by the battery
Connect it right (see circuit on picture)
Battery+ > conductor wire > button > conductor wire > +SMA- > conductor wire > Battery-
=> Solder or crimp the conductors to the button and battery
When making the most simple construction, with a one way mechanism and one power source;
> The Nitinol cool by itself down after a few seconds and therefore expand slightly back in shape. But it docent find its way to a fully stretched out shape by itself. For that you have to build a, bit more "advanced" mechanic construction (=> see Step 9)
DONE! YOU MADE IT :-) Now you should have an electro-mechanical component, with a non-motorised actuator (SMA) connected to a battery and a button to control the power supply / movement mechanism.
NOTE: 1. when working with a 9V battery do not go under a length of 10 cm > the wire will get to hot and burn out (loose its function) / 2.) overheating means memory loss (voltage is too high) > you will notice that it happened by some slight smoke clouds that will show up / 3.) Unfortunately you can work with a regular 6V battery = the current it to low and the resistance of the wire to high, to get into actuation mode / 4.) When working with Polyester fabrics, you risk that the fabric melts when the wire gets too hot. The plissé fabrics are out of polyester, so I did it like that anyways, and it works well. So just make sure not to go under certain lengths with your Muscle Wire, or work with a too high voltage when combining SMA with fabric. But I guess its anyways good not to works with too hot stuff, when using it in the context of garments (you or the wearer shouldn't get burned) => If your are an electronic engineer or good with calculations for electronics, you can also calculate the exact length and voltages that work well, by using the data on tech information sheets. But you can also play with it until it works best, just remember => NOT UNDER 10cm AND NOT OVER 9V + MAX 2SECS OF POWERING TIME (in this combination) > thats about the max :-)
Step 8: Pin the Muscle to Test the Movement
Lay the fabric flat and or place it where and how it should hand text the SMA actuation in combination with the placement and fabric surface, by pinning it carefully on (Carefully to not stitch the pins into through the fragile silicone tubing). Then put it to a current. The amount of Voltage, the duration of powering and the lenght of the SMA are the factors decide how much the yarn heats up in how long time, so they have an impact in the speed of the movement. The SMA will work, when under current like a non-motoric actuator, meaning that location where you place the wire descides over where the action will take placw / where it will deform.
As the nature of the Shape memory material is that to remember its original shape when it was heated up; means that you can expect that the fabric will shrink or gather in this place when connected to a current.
Handstitch the non motoric actuator
of the and hand-stich the SILICONE covered SMA wire in a few places onto it.
Handstitch the non motoric actuator of the and hand-stich the SILICONE covered SMA wire in a few places, invisibly onto the backside of the fabric. Best is to use the same colours yarn as the fabric or thin, transparent fishing line.
Step 9: Ideas for More Advanced Mechanical Constructions With Muscle Wire
This Instructable explained the very basics to create a flexible construction using SMA wire.
But as earlier mentioned, this is only a one way mechanism, so something like "flexing" the muscle isn't possible. If you want to create a movement that can also return , your construction needs to be a bit more advanced.
But you can still keep it simple by:
Using weights to build a counter mechanism > this is about the most simple thing you can do.
On the pictures, I stitched lead tape on the opposed end of the fabric. That way gravity just does its magic faster and the fabric will be pulled open again when you stop powering the Muscle Wire.
Using a 2nd SMA wire to build a push and pull mechanism > another, a bit more advanced, method would be to attach another SMA wire to the end of the first wire (see video) If you then power them alternately, you can make a push and pull mechanism and make the muscle thing "flex". For that you would need though either a button that can have two level/stages+an OFF one, or just double up in material and connect the two simply by taping or using the shrinking tube to attach them to one another.
>A third thing would be to try and work with elastics (similar to weights), but that I haven't tried out yet.
Step 10: USE CASE 1 - Articulated Dress
Made for Telekom Fashion Fusion (2016/17)
Shape changing garment using shape memory alloys (SMA) and movement recognition.
A collaborative project between Prisca Vilsbøl and me about combining the possibilities of Shape memory materials with motion tracking, through Fashion Technology
(Sponsored by Telekom, Adidas, Intel, Wired, Co sponsored by Statens Kunstfond)
Step 11: USE CASE 2 - ZIZ Interactive Theatre Costume
Costume Design for "Back to the Future", by "Neue Dringlichkeit" (2017) / performance/installation @Gessnerallee Theatre, Zürich
Shape changing costume using a hacked wearable (Myoband) with gesture control
The Myo-band reacts to three different hand gestures. When it recognises one, it gives a custom-build PCB the impulse to power the SMA wires for certain amount of time and with a distinct amount of current, depending on their length (Project-collaboration with http://www.raquenaengineering.com)