PLACE: Onl'Fait, Geneva
DATE: 5, 12/1/2018
PEOPLE: Cristina, Giorgia
STEP 1
I used Shape Memory Alloy (SMA) wires to make a sample of tissue showing smocking point. Smocking is an old textile technique that gathers fabric in certain pattern to create 3D decorative pattern on textiles.
MATERIAL
- SMA wire type 1
- Diameter: 0.15 mm
- Recommended current: 0.41 A
- Resistance: 55 ohms/m
- Activation temperature: 70 degree Celsius
- SMA wire type 2
- Diameter: 0.30 mm
- Recommended current: 1.5 A
- Resistance: 12 ohms/m
- Activation temperature: 100 degree Celsius
- conductive thread
- wires and wirestripper
- cotton fabric
- crocodiles wires
- 3 x 4,5 V batteries
- bench power supply
CREDITS
STEP 2
TEST 1 AND ISSUES
I prepared the muscle wires type 1 by heating them with a lighter and crimped the extremities with small metal beads to facilitate the connections. I used conductive thread to connect the 4 muscle wires to create a smocking pattern.
I then connected the extremities of the circuit to 1, 2 and then 3 x 4,5 V batteries. The circuit didn't behave as expected and only 1 wire at the time was going back to its original shape (a coil shape).
EXPLANATIONS
- The conductive thread introduced a too high resistance and the circuit wasn't closed
- It was extremely difficult to calibrate current and voltage with batteries (even though I made calculations based on the wires characteristics): only 1 battery was not enough but 3 made the fabric burn
- The connections between the wires and the threads were not perfect
STEP 3
TEST 2 AND ISSUES
I replaced conductive thread with stripped wires, SMA wire type 1 with 2 and I used a bench power supply to regulate current and voltage. I also soldered the connections between the muscle wires and the stripped wires.
I regulated the current but again the circuit behaved like it was open and I was not able to control the 4 wires. I then connected only 1 muscle wire stitched to a piece of fabric and find the optimal conditions: 3,6 V and 1,5 A.
EXPLANATIONS
- The connections between the wires and the threads were not good
STEP 4
NOTES
The next time I will use smaller pieces of muscle wire to produce a nice effect on the fabric; I will test each wire before connecting them and check carefully the connections between the muscle and stripped wires. I will also try to use copper wires as suggested by Wemakeit.