Who: Women and vulnerable communities e.g. LGBTQ+, children
What: A discrete pin-able patch and a bracelet
When: Can be used in everyday situations – women’s march, pride celebrations, walking down a dark alley,
Where: Pinned onto clothing or worn around the wrist
How: Sends a distress signal, perhaps with GPS location, when the bracelet is pinched or the badge is pressed. Ideally, the signal would be sent to an application on a phone that would pass the message to a designated party e.g first responders or family and friends.
Technique chosen: In the beginning I decided to either knit or weave as I wanted to create a push button controller and a pinch controller. I settled on knitting as I felt that weaving might not work for the push button and may have been too stiff. However, now with hindsight, if I were to continue with the idea of a safety bracelet, I would use the weaving technique to create the pinch controller.
Badge & Bracelet design & design:
Below is how I envision the push button and pinch mechanism envisioned in a wearable version of the safety badge and safety bracelet.
Push Mechanism Design for Safety Badge
Pinch Mechanism Design for Safety Bracelet
Process: The Badge
- Prepare your materials and cut felt according to the size of badge you want. i.e. This design is for a square badge.
- Cast-on 10 stitches onto the knitting needle. Begin with your non-conductive piece.
- Knit in your preferred knitting style.
- Once you have a square piece, cast-off the stitches to complete the square.
- You should now have a non-conductive knitted square.
- Begin the next square by joining your conductive thread with the yarn to form one thread.
- Leave a “tail” of at least an inch in length and then cast-on 7 stitches.
- Knit in your desired style for 7 rows or until you have a square then cast-off.
- Repeat steps 6-8 to create a second conductive square. Ensure that each square has a “tail”.
- Sandwich the non-conductive part between the conductive parts and use the e-textile testing tool to test that the push button mechanism works. Tip: Ensure that the stitches on the non-conductive part are loose.
- Sew one conductive square to one side of the felt piece.
- Sew the other conductive square onto the opposite side of the felt piece ensuring that the tails of the pieces are on opposite sides.
- Pick one side of the felt and sew the non-conductive piece over one of the conductive pieces.
- Fold over the felt and test the safety badge lights the LED on the e-textile tool.
Process: The Bracelet
- Cut two 1/2 inch wide strips of conductive fabric.
- Using an LED and your battery from the e-textile testing tool, designate a + and – side to the strips.
- Place the remaining LEDs onto the strips and test that they all light up
- String some conductive thread through a press stud and sew a running stitch into the positive side of the conductive strips. Make sure that the press stud fits over the positive side of the battery pack’s press stud.
- Begin sewing the “legs” of the LEDs onto the positive strip.
- Sew all 5 LEDs onto the strip and snip the conductive thread when you get to the end of the positive strip or after the last LED has been fastened to the strip.
- Sew down the LEDs on the negative strip and snip the conductive thread leaving a tail.
- To create the knitted strip for the pinch circuit begin knitting with a mix of yarn and conductive thread. Ensure that you leave about a 1 inch tail.
- Knit for about 7 rows and then continue knitting with only yarn. You can snip the conductive thread.
- Knit with only yarn for 10 rows then attach the conductive thread at the end of a row and continue knitting a new conductive part.
- Knit for 7 rows and then cast-off and snip the yarn leaving a tail of conductive thread.
- Attach the tail with yarn and conductive thread mix to the conductive thread tail from the negative strip from step 7.
- Attach conductive tail end to another press stud that fits over the negative side of the battery pack.
- Complete the circuit by attaching the battery pack i.e attach the press studs.
- When you pinch the knitted part, the LEDs should light up. I realized that the blue and green LEDs would not light as the 3V battery did not have enough voltage for the 3.2V bulbs.
- I switched out the LEDs using red, yellow, and orange LEDs which required 2.2V and all of them lit up as seen in the last picture.
The technique of working with the LEDs and was inspired by this post.