A Spoonful of Spice

Recipes for low-sugar living + treats for special occasions

Making Soft Circuits: Batman Wristband

Project: Design a wearable for a superhero. 

Materials: Felt, conductive thread, needle, LEDs 

Product: I designed a light-up wristband for batman. With a pinch or push on the band, Batman can now find his way in dark places or can momentarily blind perpetrators with LEDs to escape. 

Design Tips: One LED isn't going to be bright enough to startle anyone; I suggest using 4 LEDs. To power all 4 LEDs, you'll need to make a parallel circuit (i.e., separate + and - paths for each LED that merge back to a central + and - path). I also used a felting pen to connect the bat symbol to the wristband more seamlessly 

Process: It was helpful to sketch the circuit design first, then mark off lines on the felt before stitching. I also found that it was easier to insert the LEDs into the threaded circuit after sewing rather than sewing them on one by one. Finally, check to make sure that when the band is folded over, that no unwanted threads end up touching each other. The only touching threads should be on the end of the wristband next to the velcro. Alternatively, you could use conductive velcro to simplify. 

Execution tips: To ensure contact with the thread and the wires, wrap the thread 3 times around the wire or the + or - hole in the battery holder.  Secondly, for each side of the switch, sew a solid square, rather than a couple stitches, to ensure contact and make sure they line up appropriately when wrapping the wristband. Finally, make sure there is some ways to access the battery, so it can be replaced, without destroying the band, if needed.