Wearable Circuit – Jovana Ivanovic

For the 12 hour circuit project I decided to work on a certain accessory, in particular some form of jewelry. The original prototype involved knitting a hat that would light up in the absence of light using a photo resistor. However I grew frustrated it and decided to attempt something else. I ended up utilizing elements from a previous prototype of mine that used vegetable paper and an LED. The main concept behind this jewelry piece was to have it simplistic in design, while at the same time looking elegant, along with being able to wear it on a daily basis. A necklace composed of a thin wooden frame, vegetable paper, and the LED was the best design due to the size of the jewelry. My inspiration for the particular design was from fireflies, whom utilize their bio-luminescence to attract mates. The beauty of this piece is that it can be worn lower down and be taken to parties such as a rave dance or a simple club.


It was simple to fulfil the criteria of hiding the light source, as the LED was to be placed within the necklace and concealed by the vegetable paper. In the process of making the vegetable paper I ended up ruining my blender, but it turned out nicely. The LED circuit uses a 3volt battery as an energy source, and it has a 150 ohm resistor soldered onto it. The circuit isn’t mounted, however it is fully stable in a way that it’s possible to make it light up when you want to. It is somewhat flimsy when a person moves, and it flickers because the connection isn’t mounted, however I decided to keep it like this as the flickering attracts more attention than just lighting up. I didn’t introduce the blink sketch because all the micro controllers that I own were too big, so I made a more simplified version of it. If I had used a micro controller I would be able to control the pattern of the lights and make it similar to a fireflies mating call.

I had to make sure the wires that are connecting the battery to the LED not touch anything and burn up. Having a necklace that lights up is very cool, but not when it’s on fire. I solved this issue however by putting something non conductive between the wires and the metal dowel in the middle. The second difficulty while making the frame was attaching each individual part that had to be sanded delicately due to how thin they were. There were multiple instances where the frame actually snapped due to pressure, so I had to increase the thickness of some parts of it, or by simply gluing it back together. It was not possible to use a hot glue gun when attaching the frame together as when the glue cools down it creates a gap between the wood, which would then either break apart or simply look unappealing. I was attempting to go for a more rustic feel with the necklace, so I had to change a few things with the necklace to make it better. At first I used thin leather strips, however the leather cut into the back of my neck and over time it started hurting. I ending up replacing it with twine as it reduced the friction since it wasn’t as smooth as the leather.


It was enjoyable to wear the necklace, and I received much praise and comments about the jewelry. Often times people would ask where I had bought it, perhaps online, only to be amazed when I revealed to them that it was hand made. I had to be careful of not letting the LED inside the frame bounce around too much from movement, or else it may disconnect. However when simply walking and standing it posed no problems and was extremely light. At first I thought the size of the necklace would be too large, so I had to decrease the original size of it, and I felt it was a good move as it made it easier to wear while still being noticeable. It was especially fun to wear this during the darker hours of the day, however it doesn’t serve as an effective piece of lightning.

LED Necklace

For this project, I have created a necklace that is made out of the glue from a hot glue gun. Attached within the necklace are LED lights that light up once the necklace is on the person. I chose to use the hot glue as my primary material because it has a flexible and transparent quality, which allows the colors of the LED light to travel from one end to the next.


Throughout the whole process of the project, I have encountered many problems with the technical aspect of the circuit. Since I decided to work with a more complicated pattern, it was extremely challenging for me to avoid overlapping the wires. It took a lot of time and concentration in order to create a circuit consisting of 5 LED lights.  The idea came to me one day when I was experimenting with my hot glue gun. My original idea was to combine the optic fiber with the led light to create a trail of light on clothing. But after discovering this material, I decided to create a more unique piece that people don’t see very often in jewelry or other forms of crafts. After wearing it for the 12-hour period, I have noticed that this necklace is extremely eye catching. Whether I was walking on the streets or hanging out with my friends, this piece of jewelry attracted many peoples’ attention. With the LED lights attached to the necklace itself, the necklace is a handy piece when it comes to parties or any social events. The only few negative aspect of it is that you cannot change the LED lights because they are embedded in the glue. Since this is more of a fun piece of jewelry, the comfort level and the design may not be suitable for all locations and social events. It is designed more for the purpose of costume wear instead of everyday wear.


Since I know very little about technology and circuit flow, this piece was definitely one of my most challenging pieces I have ever created. But after learning more about connecting circuits, this piece has inspired me and has broaden my view on the things I can do with wearable technology.



Cathy Lai 12 Hour Circuit Necklace

1) When I began working on this particular assignment, I was simply clueless as I was unfamiliar with electrical circuits. After having all the materials ready, I performed some trial and error with regards to the building of the circuit.
2) I found the most challenging part to be the soldering of the power switch to the breadboard; it was difficult to do so without detaching the circuit.
3) After the circuit was completed, it was time to play with the materials =)
4) The challenge I had with the jewelry was that every time the breadboard touched the metal ball it caused the LED to shut off. In order to avoid the problem, I had to flip the breadboard to the non-conductible side.
5) The Last step was to attach everything together with hot glue.




I attached my jewelery to a hairband so that it can be used as a regular hair tie during the daytime. At night, the LED attached to the jewellery can be turned on and used as a means of a safety device.  In terms of my experience with regards to the use of this item, it was comfortable at first as if I was wearing a regular hair tie.  However, approximately after two hours of use, I began feeling a minor headache due to the weight of the jewelery.   Other than wearing this piece of item as a hair tie, there are several other ways to wear the device:





Greg McRoberts 12 -hour circuit

12-Hour Circuit Necklace

Transformable Headband

My idea is to make some kind of “transformable” wearable, which user can change its parts and functions as wanted. That wearable should be small, simple and easy enough to make, so after a while of thinking I decided to make a headband. I started with drawing a simple diagram and collecting the materials that’s needed to complete the task.

I choose decorative ribbon instead of fabric to make the headband because the ribbon is easier to keep in shape. Later I kind of regretted this choice since it was super hard to sew into the material. Luckily I managed to get through this with a large needle.

First step is to wrap the ribbon around the headband and make a simple bow.

Second step is a bit tricky since I must use a big needle (the conductive thread that come with the kit was big) and fit it into the smallest size snap button. Good thing they fit perfectly. I just need to tie the thread around the battery holder with my hand because there is no way the needle can go through there.

So I ended up with a headband that carry the battery holder connected to two snap buttons.

Testing the light before sewing it into the bow.

Sewing the LED light with the resistor and connect the two sides to two snap buttons.

The light will turn on when I snap in the two buttons, it was bright enough to see at night and I feel comfortable wearing for hours. I didn’t even realize I’m having a light on my head sometimes.

For the second iteration I add the light sensor on the circuit. I want the LED to light brighter in the dark and darker in daytime. It turned out that only adding the light sensor is not enough because it actually did the opposite: the LED light brighter under the sun and stop lighting in the dark (!). I then learnt that I have to put two transistors in the circuit to do the trick.

I also try making another part without the LED, and end up with using a motor to make this little fan. I found out it’s too heavy to be a part of a headband, but would work find with a necklace. However unlike LED lights the battery run out pretty fast with motor.

Final work


Illustrated Circuits – Not Afraid of the Dark + Hey

For the 12 Hour Circuit assignment, I chose to create characters and have them show some interactivity based on LEDs. I chose the dark-detecting circuit tutorial that is posted on the Evil Mad Scientist as a starting point. This circuit uses a phototransistor  paired with another transistor in a Darlington pair, as described in the tutorial. I love arm warmers as wearable art pieces, partially because I can look at them while I’m wearing them, and be entertained by my silly drawings.

The first iteration was the “Not Afraid of the Dark” illustration. I used electrical wire for the connections to the LEDs and the phototransistor. I prototyped the simple circuit on a small breadboard, and separated it from the battery pack with some foam pieces.

What I noticed about wearing this piece was that the battery pack on the outside was very janky and floppy, and I hadn’t anchored it down enough for it to be that wearable. The wires on the inside, which I had tacked down with basting stitches, were not really keeping their place. Having a fabric liner to contain the electrical items would have helped.

The phototransistor was not sensitive enough to turn off the yellow LEDs in indirect sunlight. I found that it only work in extremely bright incandescent light, or in direct bright sunlight. One example of the dark-detecting circuit showed how to make it more sensitive with a 5k potentiometer, but I did not have time to attempt it. The final two thumbnails below show the circuit with the eyes on, and with them off as the little critter basks in the glow of an incandescent lamp.








Improvements based on the first iteration that I wanted to try for the second included:

  • Using conductive thread instead of wires to connect the LEDs with the power source
  • Trying a different kind of switch on the circuit to turn on the eyes, as I was a little disappointed in the sensitivity of the phototransistor and wanted to see a quicker change with the eyes turning on and off.
  • Using a 3v coin cell battery instead of two AA batteries in a holder, so I could have a more discrete power source tucked into the inside of the cuff.

I found some copper rivets in my sewing kit and tested them with my multi-meter to see if they had a coating or could be conductive. They were, so I used those to anchor  conductive thread and the wire from the battery holder to. I did have some issues connecting the rivet to the fabric, and needed to use interfacing or something else to stiffen the fabric.

Keeping in mind that each element I stitched to the surface of the illustration had its own aesthetic, I used the LEDs, resistors and thread to accentuate the painted character. The ears could have used a little more work, as the stitching above them was really boxy. In general the second iteration was much lighter and easier to imagine as a wearable arm warmer or patch that could be pinned to clothes. The conductive thread I used worked very well in the circuit, and rubbing a little beeswax on the ends of the thread made it much easier to thread, although it could impact conductivity if used a lot at the end of the thread. I didn’t notice any issues with it though, and found that after I had warmed up the wax with the barrel of my soldering iron, it made it easy to pass the conductive thread over it to pick up a bit of wax.

The switch I used turned the red LEDs on only when I pressed it. I would have preferred a switch that could have turned it on, and then off again, but this was an amusing outcome and certainly would allow for the battery to last a long time. The 3v coin battery worked well to power this simple circuit, and the resistors added the right kind of anxious character to the face of my illustration.

dyeing necklace ….

This project started out as a jacket with light up buttons.





I thought it was due last week so I had the whole thing done a week early. But then I started thinking it was lame (and ugly !!!!!) and it was breaking a lot so I thought I would just start again. So then I got the idea for a really intense and cool project that I won’t talk much about because it never got made. (Maybe one day I will make it). Instead I went with a different project, that sort of just happened while I was experimenting with the first 2. This project is the dyeing necklace.




It is made out of resin. I vacuum formed half a Styrofoam ball, then filled it will resin. In the resin I put in a small little LED circuit, with a 3V battery pack and a red LED. The light and battery are completely inside the resin, so once the battery runs out there is no way to change it, or if the circuit breaks it cannot be fixed. It is hooked on a chain so it can be worn as a necklace. At first when you wear it around it will be nice and bright and shiny, it will glow and when you walk around people will look at you and comment and be like “nice necklace!” but eventually, the light will become dimmer and people will stop noticing the glow. Maybe one or two people will see it. Eventually the light will go out, the battery will be empty. You will just be walking around with a large half ball of resin with a dead battery in it. Just another grim reminder that eventually all things will come to an end.









When I wore the necklace for 12 hours I did not enjoy having it light up. It was annoying and distracting to have a red light on me and it did not look good. When it got dimmer I was happy, but by like the fourth hour it went out and I was like “oh…that’s sad.” I found myself missing the light when it burnt out. It was funny but weird.

When the project was first realized it reminded me of the part of the movie Aladin when Jaffar put Jasmin in that giant sand timer…




ps. all the projects were lite up at one point in their lives. Just not in these pictures…..