Laboratory Blog: Pocket Workshop

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August 12, 2005

Pocket Workshop

The following text gives step-by-step instructions how to make an LED circuit with conductive fabric, thread and epoxy embedded into a denim pocket. This was the topic of the workshop we presented at Eyebeam in July, 2005.

LessEMF - Source for conductive fabrics and velcro. For $10, they offer a fabric sampler to try out different materials.
Mood Fabrics - Our favorite fabric store. For our pockets, we used denim and regular pocketing. Sometimes you can find conductive silk organza at Mood, so bring your multimeter.
Botani - Botani only sells buttons. They sell traditional metal snaps in bulk.
Newark in One - Good source for conductive epoxy and electronics supplies. We used conductive epoxy to attach the snaps to the 3D printed LED holder.
L.C. LED and LSDiodes LED resources

Conductive thread - The conductive thread we used, did not work well in small amounts so we replaced it with fine gauge wire. There are some conductive threads and information available online:
Lamé saver
Intro to Wearable Technology

Cut out pocket pieces from fabric and pocketing. To make a pattern, draw out the size and shape of the pocket, then add 5/8" around all edges for seam allowances. Press the 5/8" seam allowances down on all sides with an iron.
[pocket pattern]
Attach conductive velcro to both sides of the pocketing. This will be where the battery is attached later on. We recommend using the loop side of the velcro to the pocketing. We attached the velcro to the pocketing using regular thread on a sewing machine.
Using conductive epoxy, attach velcro to both sides of a 3 volt battery. Make sure that the velcro does not touch the outer ring of the battery or it will short the battery. The photo shows a battery with loop side on the battery, but hook works better to minimize the chance of a short circuit.
Next, we cut conductive fabric out for the front and back of the pocket on the laser cutter. The fabric can also be cut the traditional way, with scissors. The conductive fabric is going to be part of an electronic circuit so it has to be continuous. That is why all the letters in the graphic are attached to each other.
Attach the conductive fabric to the pocket material, in our case denim, with regular thread. Both pocket pieces should have conductive fabric sewed to it. Make sure the fabric will overlap the velcro on the pocketing when it is all put together. Sew conductive thread creating continuity between the conductive fabric and the velcro on the inner pocketing for both sides.
We made a plastic housing for the LED using the 3D printer. With regular 5 minute epoxy, we attached an LED to the housing. With conductive epoxy, we attached 2 female snaps to the housing. Afterwards, always check for continuity with a multimeter.
Attach two male snaps to the front of the pocket for a place to snap the LED assembly to. First attach the snaps with regular thread and then go over it with conductive thread. One snap should sit on the field of conductive fabric and the second snap should sit on the denim. Make sure there is no continutiy between the two male snaps.
On the pocketing material, attach a male snap that lines up on the inverse side of the denim snap on the front of the pocket. Attach it with regular thread first and then use conductive thread to create continuity between the male snap on the front on the pocket with the male snap on the inside of the pocket.
On the pocketing for the back of the pocket, attach a female snap that meets up with male snap you just added to the front pocketing. After attaching the snap with regular thread to the pocketing, use conductive thread to create continuity between the snap and the conductive material on the back of the pocket.
Sew the pocketing material to the pocket material and sew up the pocket around the outside edges.