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NITINOL
Also called "Muscle Wire"
Page 1
P2
P3
Nitinol
SHORTENS
in length when current flows through it:

Click the switch (and hold it down) to observe Nitinol wire in action
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Latest News:
I have received an email from Jeff Brown of
Dynalloy, (one of the
manufacturers of Nitinol and Flexinol).
He asks me to point out that Flexinol is used in actuators.
Nitinol is not suitable for
actuators.
Nitinol and Flexinol are also available
as rod, tube, sheet as well as many other shapes and you should read the
information on the company-website before making any decisions.
The number of applications for this type of product are enormous.
Here are some
interesting links:
About Flexinol
About Nitinol
Links
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Nitinol
is a SHAPE MEMORY ALLOY made of nickel and titanium that
SHORTENS
in length when
current flows through it.
Nitinol changes shape when heated but returns to its original shape
when cooled. Nitinol requires a "retuning force" to return it to its
original length after current has been turned off. It does not return to its
original length by itself.
BUILD A ROBOT ARM
A
demonstration robot arm can be made with a short length of Nitinol and a
few extra components as shown in the animation above. Nitinol
is called Flexinol and possibly vise versa by the layman, but the two are not
the same in performance. This website describes the two materials as equal but
you should go to
Dynalloy
website to see the differences.
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The components you will need are: |
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15cm (6") Nitinol (150 micron - 0.006") wire (also
called muscle wire or memory wire)
2 Nitinol wire connectors
20-22 gauge stranded hook-up wire
small plastic sandwich bag
2 AA batteries
1 battery holder
1 switch
2 tacks
1 brass paper fastener
paper clip
10-20 coins |
PROCEDURE
- Drill a hole
in one end of each craft stick. Place the arms of the paper fastener
through the two holes and bend them back to make the elbow joint,
which should move easily.
- Bend each
end of the Nitinol / Flexinol wire to form a loop and attach connectors by
crimping to hold the wire in place. Make sure the connectors
are tight enough to hold the wire loop in place. The loops will serve as
attachment to the craft sticks.
- Use tacks to
attach the loops to the sticks. The Nitinol should be
long enough to hold the sticks at a right angle when the wire is
taut.
- Secure
the upper part of the arm by clamping it to a structure so that it hangs perpendicular to the ground. Put enough
coins a plastic bag to keep the wire taut and hang the bag from the arm.
- Connect the positive lead from the battery
holder to the connector at one end of the Nitinol wire and the negative
lead to the other end, via a switch.
- Switch the circuit on. Observe what happens when current passes through the Flexinol
/ Nitinol wire. Switch off and allow the wire to recover. Add coins to the plastic bag to see how much mass your
robotic arm can
lift.
Specifications for
this simple lever arm
Voltage: 3 Volts
Current: 375 milliamps
Resistance: 8 ohms
Power: 1125 milliwatts |
Wire Length: 15 cm (relaxed)
14 cm (contracted)
Wire Force: 3.3 Newtons (330gm) |
Sources of Flexinol
/ Nitinol:
The following suppliers have their own kit(s) as well as wire by the
foot. You need to observe the minimum order value with some companies
and the cost of postage:
Dynalloy Inc. http://www.dynalloy.com/
Sample Kit:
1 - 3" sample of .003"
diameter low temp FLEXINOL™ actuator wire
1 - 3" sample of .005" diameter low temp FLEXINOL™ actuator
wire
1 - 3" sample of .006" diameter low temp FLEXINOL™ actuator
wire
1 - 3" sample of .006" diameter high temp FLEXINOL™ actuator
wire
1 - Baseboard for mounting these projects on
10 - Push pins for mounting to the baseboard
10 - Small tubes for securing the push pins and covering their sharp
ends
3 - Small springs
1 - 3 Volt Battery pack (with one alligator clip)
2 - Small lever arms
1 - Holding bracket for connecting the levers in project 3
You will also need 2 AA batteries
Sample Kit $29.95 plus $4.50 postage
SHAPE MEMORY APPLICATIONS inc
http://www.sma-inc.com/
Nitinol Engineering Kit:
Intended for design and development engineers and students.
The Nitinol Engineering Kit contains "Using Shape Memory Alloys"
(a simple design guide),
1 to 2 ft. of actuator wire, three demo wires, 1
foot of super-elastic wire, 1 tension spring, and 1 compression spring.
Cost: $49.95 plus tax and shipping
Mondo-tronics Inc. http://www.mondo.com/
(other kits available too)
MW Super Sample Kit view
kit
A quick and economical way to try a wide range Muscle Wires sizes. The Super
Sample Kit includes 20 centimetres each of five diameters (037, 050, 100, 150,
250) in both low temp (LT) and high temp (HT) formulations. That's ten separate
Muscle Wires, two meters total, and includes crimps and technical
specifications for all the wires. Cost:
$29.95 plus $4.95 postage. (plus CA tax)
SW Wire & Wingbases view
kit
A minimal kit for making your own Space Wings-like creations, or for repairing
or upgrading old Space Wings. With two wingbase strips, and 14 cm of Flexinol
100 HT Muscle Wire - enough for two complete Space Wings. Cost:
$10.00 plus $4.95 postage. (plus CA tax)
Space Wings Kit view
kit
Now Variable Speed!
Sleek silvery mylar wings flap silently using only five centimetres of Muscle
Wire. Perches on you computer, annoys cats, amuses babies.
Space Wings stands 15 centimetres tall and flaps up to 36 times per minute.
Includes a printed circuit board, parts, & detailed instructions. Assembly
requires soldering iron, solder, screw driver, wire cutters and two
"AA" batteries. For ages 14 and up. A great first electronics kit
& excellent hands-on introduction to electronic construction & Muscle
Wires. Cost:
$19.95 plus $4.95 postage.
Electric Piston Demo Kit view
kit
Includes one piston, one high capacity Polapulse battery, two connecting leads,
and complete instructions with plans for four complete projects. Cost:
$19.95 plus $4.95 postage. (plus CA tax)
IMAGES SI
Inc http://www.imagesco.com/catalog/nitinol/index.html
(other kits available too)
Nitinol Rolling
Ball Demo
This very simple device rolls a small ball back and
forth inside a clear straw. It was made to demonstrate how Nitinol actuator
wires continue working over a fixed range of motion for years. It operates
about 20,000 cycles per day. It also happens to be a good way to introduce the
theory of actuator wires. Cost:
$24.95 plus $8.50 postage
Nitinol Air Valve
This is a fully functional electric valve made with
Nitinol. It permits proportional control of the air or fluid flow. When voltage
is applied the Nitinol inside contracts, opening the valve.
Cost: $17.95 plus
$8.50 postage
Nitinol
Butterfly
Another Nitinol demonstration of long life and durability, its beautiful
lifelike motion makes it a great gift as well. It may be used with flowers in a
lifelike setting or as a stand alone somewhere, perhaps a computer top.
Cost:
$34.95 plus $8.50 postage
Nitinol Wire (plus $8.50 postage)
Diameter
(inches) |
Cost
per foot: |
| 0.006 |
$5.00 |
| 0.008 |
$5.00 |
| 0.010 |
$5.00 |
| 0.012 |
$7.50 |
| 0.015 |
$12.50 |
Monarch Butterfly
Stock Number:
CR30825-34 Edmund
Scientific
A unique way to draw attention to your display. Elegant Aliforms™ are
lifelike noiseless, motorless animated butterflies. The lifelike
open-and-close motion is created by use of memory wire called Flexinol™.
Simply plug in the 6V adapter (included) and the heat of the electricity
contracts the Actuator Wire like a muscle. The Actuator Wire then relaxes
when it cools. Aliforms™ can be attached to flower displays, plants, or
anything else, to draw attention. Comes in Monarch version only. Note: the
6v adapter is INCLUDED!
Cost: $29.95 plus $7.75 post
Monarch Butterfly
also called: Nitinol
Butterflies
(4 different types)
These authentic-looking butterflies really flap their wings! The wings
move once every two seconds, just like a resting butterfly. Just
attach these butterflies to plants, picture frames, or your computer
monitor. The wings move thanks to nitinol, the muscle of Stiquito.
Comes with a 115v transformer and long
cable. Cost:
$33.00 incl post (Pay by PayPal)
Experinmental Flexinol (Nitinol)
30 cm long (1ft) Flexinol is great for experiments.
ST-004 is 0.004” diameter.
ST-005 is 0.005” diameter. Prices include shipping: (Pay by PayPal)
(International orders
50˘ extra!!)
Nitinol/Flexinol Wire
(includes postage!!)
Diameter
(inches)
|
Cost
per foot: |
| 0.004 |
$3.00 |
| 0.005 |
$3.00 |
The two
sizes are also available by the metre for $10.00 per metre (incl post).
(Pay by PayPal)
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Stiquito
project Comes with book $33 (posted)
(Pay by PayPal)
Click
HERE
for a review with pictures.
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Read
the first chapter of "Advanced Experiments with a Simple and
Inexpensive Robot" by James M. Conrad
and Jonathan W. Mills.
Chapter 2 has detailed assembly instructions
for constructing the Stiquito robot, so it looks like this is
the best book to get. It comes with a Stiquito kit. Cost is $48.00 plus
postage (for book and kit). Standard post is $8.00 If you are a
member of IEEE Computer Society, the cost is $36.00 Click HERE
to order.
To understand more about Stiquito and the books on Muscle wires, click HERE.
(very good info)
THIRD STIQUITO BOOK
See details of the third book in the series: "Stiquito
Controlled." It is written by James Conrad, and his website is: (http://www.stiquito.com).
The book comes with all components to build the robot and is based on a Texas
Instruments MSP430F1122 processor. The board will make the robot walk and
comes with instructions to reprogram the board, to do other things. You can
use the board for almost any application. The board is 3.3" by 0.75", and has
a small prototyping area on it.For an example of a similar
model (NITLEMITE) you can build yourself from Lego blocks, click HERE.
World
list of robotics info.
Crimped
Flexinol (nitinol)
(ST-006).
4-inch long Flexinol
(0.004” diameter) and is crimped onto 4” of wire wrap wire at both ends.
Cost: $4.50 including post
(International orders
50˘ extra!!)
FEATURES:
Nitinol straightens out when heated. It can also be
"trained" by shaping it within a flame to produce a new shape such as
a square. It can then be bent to another shape when it is cold. It will
return to a square when placed in hot water.

LiveWire can be
purchased for approx us$4.00
plus $8.50 postage
Livewire is a fun little toy. According to the
directions, you place it in cold water, bend the wire into any shape you want,
then place it in hot water and the wire pops back into shape.
Livewire toy is made of nitinol wire with a low transition temperature (the
temperature of hot water). When placed in hot water the wire will unfold and
unbend itself (if bent out of shape), reverting back to its original shape.
Nitinol fun products can be purchased HERE.
Shape Memory Alloys
have a memory that returns after heating
PROPERTIES OF NITINOL by
John Iovine
When Nitinol actuator wire is used as in the guidelines below, it can
be expected to last tens of millions of cycles. If it is stressed or overheated
due to a higher current, good motion may only be obtained for a few thousand or
few hundred cycles, depending upon the severity of the stresses. Care should be
taken to adhere to the following current limitations:
|
Dia
(micron)
µ
|
Dia (in)
|
Dia
(mm)
|
Resistance (Ohms/inch)
|
Maximum Pull Force (gms.)
|
Approx Current at Room Temp (mA)
|
Contraction Time
(sec)
|
Off Time 70şC (sec)
|
| 37µ |
0.0015
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0.037
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21.0
|
17
|
30
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1
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1
|
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50µ
|
0.002
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0.05
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12.0
|
35
|
50
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1
|
1
|
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100µ
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0.004
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0.1
|
3.0
|
150
|
180
|
1
|
1
|
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125µ
|
0.005 |
0.125 |
|
|
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1 |
1
|
|
150µ |
0.006
|
0.15
|
1.3
|
330
|
400
|
1
|
2.0
|
|
200µ |
0.008
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0.2
|
0.8
|
590
|
610
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1
|
3.5
|
|
250µ |
0.010
|
0.25
|
0.5
|
930
|
1000
|
1
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5.5
|
|
300µ |
0.012
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0.3
|
0.33
|
1250
|
1750
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1
|
8.0
|
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375µ |
0.015
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0.375
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0.2
|
2000
|
2750
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1
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13.0
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Note: One micron = one
micrometre. 1 micron =
1/1,000,000metre 1 micron =
1µ
1,000,000µ = 1metre =
1m 1,000 micron = 1mm (millimetre)
1m = 100cm
(centimetres) 10mm =
1cm 1,000mm = 1m
100µ = 0.1mm etc
Contraction time is directly related to current delivered. The guidelines
above are only approximate, as other factors such as ambient temperature, air
currents and heat-sinking will alter the value.
Flexinol Wire Properties:
| Wire Diameter (µm) |
Linear
Resistance (ohm/m) |
Typical Current
(mA) |
Relaxation
Force
(grams) |
Contraction
Force
(grams) |
Repetition
Rate** (LT/HT) |
| 37µ |
860 |
30 |
4 |
20 |
52/68 |
| 50µ |
510 |
50 |
8 |
35 |
46/67 |
| 100µ |
150 |
180 |
28 |
150 |
33/50 |
| 150µ |
50 |
400 |
62 |
330 |
20/30 |
| 250µ |
20 |
1,000 |
172 |
930 |
9/13 |
| 300µ |
13 |
1,750 |
245 |
1,250 |
7/9 |
| 375µ |
8 |
2,750 |
393 |
2,000 |
4/5 |
** Cycles per minute, in still air, at 20°C
LT = low temp 70°C, HT high temp 90°C
Page 2 covers the characteristics of Nitinol.
P2
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01-03-03
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