Fabric Construction: The lock-it pocket
My design process for an IoT pouch that protects + tracks your valuables
Misplacing things can be a daily stressor — keys, headphones, jewelry, you name it. Sometimes I wish I had a tracker on all of my items just so I could never lose anything ever again. Based off of this pain point, I designed the Lock-it Pocket, an IoT pouch that tracks and protects your valuables.
Design
The Lock-it Pocket is for people who have trouble misplacing or losing their belongings. When the user places an item inside the pouch and closes the clasp, the pouch will automatically lock. Once locked, the LED lock sensor on the front of the pouch will turn on to show the user that it is indeed locked. The user can also check the lock status via the Lock-it Pocket app, as well as locate their pouch. Because many people misplace items in their own homes, the location feature of this app will have to be very precise. Additionally, if lost outside their home, the users can easily locate and retrieve the pouch.
Prototype
To prototype the Lock-it Pocket, I used scrap jean fabric and an Adafruit Beginner LED Sewing Kit. I began by cutting a rectangular piece from the fabric, and folding the top long edge partway down to create the opening of the pouch. I secured the fold by sewing blanket stitches length-wise with pink thread. Next, I folded the fabric in half from short edge to short edge, and blanket stitched the edges to complete the pocket pouch.
Then, I began attaching the electronic parts. I made a simple circuit using a CR2032 battery, battery holder, 4 x 5mm snaps, candle flicker LED, and thin conductive thread. I poked the LED through the front of the pocket pouch, and affixed it to the fabric by stitching the legs in place with thread. I then sewed the battery holder onto the back of the pouch, in order to keep it as inconspicuous as possible. Next, I sewed a clasp onto the inside of the opening of the pouch. Lastly, I connected the parts with conductive thread as shown in the circuit diagram. The clasps act as a switch that cuts off power to the LED when the pocket pouch is open.
Analysis
After prototyping and some informal user testing, I reflected on my design choices. Although the circuit I created was simple, it proved to be finicky. When closing the clasp of the pocket pouch, the LED would only light up half of the time. I suspect this flaw results from conductive thread touching on different parts of the circuit.
If I had the time to redo my prototype, I might use enameled copper wire instead of conductive thread. When using it for a previous e-texile project, I found enameled copper wire to be the most effective in preventing crossed wires. By carefully scraping off the enamel on the end of the wire, you can make connections easily. Using copper wire might make the pouch more rigid (and less aesthetically appealing), but would improve the reliability of the circuit.
In addition, I reflected on the size of my prototype. The small pocket pouch I made was not able to hold much more than a set of wireless headphones. It would work for small valuables, but not for anything bigger. If I had time to redo my prototype, I might make it a bit bigger so the user could place more into the pouch and get more use out of it.
