Workshop #4 Notes
Timer Curtains are curtains that use thermochromic paint to allow light into a room by gradually removing the colour from the pigment on the patterns of the fabric by using electrical voltage. The heat from the voltage turns the painted pattern to white which allows for more light to enter the room. The curtains are activated by a timer or an alarm that allows the user to set either a time to wake up or to set a time that they would like to get up and take a break. The patterns gradually remove themselves one by one, so the transition from patterned curtain to white is an ambient experience. This allows for either a slow wake-up or slow reminder to that a break is coming up.
With this project, I wanted to create a product that used patterns as a form of time telling. Upon exploring the thermochromic paints I was curious as to what would happen if you made multiple tiny patterns and could control them individually. I had painted dots onto a sheet and it reminded me of the UI/UX pattern of “loading ellipses” you often see on websites. I wondered how you would be able to use this known UI/UX pattern into the physical world as a notion of timekeeping, but also keeping the connotations of a moment “loading”. I wanted to see if it was possible to gradually remove the dots over time to create a white sheet, to explore the applications of this method, and to see if it was an effective use of a clock.
Process & Explorations
I started off by painting patterns using two colours of thermochromic paint. I initially wanted to test how far the heat from the voltage could spread along one colour before bleeding into the adjacent colour pattern.
I created multiple different patterns on many sheets of white fabric, and once dry sewed some resistive thread through the different colours.
I attempted to run 5V power from my Arduino to the sewn thread using alligator clips that were simply connected to power and ground. At first, I saw no change. After seeking some advice, I realized that the distance of the sewn circuit was a big factor in the amount of heat that would be dispersed through the thread. The longer the circuit with a lower voltage, such as 5V, would only be seen if the circuit itself was small.
I adjusted the placement of the alligator clips to the first few stitches and immediately saw a difference.
I tested to see if I could make the thermochromic paint fade in an out be connecting the power to a digital output pin on the Arduino. Then I made the delay twenty seconds between turning the power on and off on the pin. In the video below you can see a slight change in the pigment.
Video if thermochromic pigment changing from the heat of the circuit.
With this knowledge and the set of tools that I had, I assessed the pieces that I painted. I saw that the dots each had a small surface area and came across the idea of slowly fading out the dots individually as a form of an ambient technology. The dots could be used as a timer: the user could set an amount of time, and the dots would slowly fade out. The dots once “vanished”, would indicate that the time is up without interrupting any thought. In terms of installment, I envisioned this pattern on windows curtains. As the dots turned white, they may gradually let in more light into the room and giving the illusion that the person who set the timer should go outside for a break. If the changing of pigment let more light into the room, the curtains would extend the act of ambient notification from simple pattern change to a lighting change in the space.
I sewed small stitches along the length of each dot to start. I then clipped an alligator clip onto the power and ground of each dot. I made sure that the dangling threads did not touch each other as I was aware of the small working space I had created for myself. Reflecting upon the soft circuits project, I did not want to have a clean workspace.
I then moved each of the pins into the Arduino digital pins and ground. I made my code turn on a new pin every five seconds. The change of the pigment was gradual but effective. Nearly the entire dot had disappeared.
Diagramming for future iterations
I started to consider how I would be able to expand this project further and to place emphasis on the concept of a clock. I sketched out some process ideas of how this could operate and look:
In these images, I had included two colours of pigment on each dot. Aesthetically speaking, I really enjoy the complimenting colour contrast of both pigments. In my first trial (the “rainbow” pattern), the bleed of the heat from the voltage did not breach onto the second colour due to the width of the brush stroke. Having different colours fade in and out at different times could be used as different types of timers or indicators.
Other use cases for the combination of thermochromic pigment and curtains.
- Inspired by Harry Potter, the curtains could be used as a “remembrall”. The remembrall is a device that changes state when the owner needs to be reminded of an item of importance.
Scene snippet of character Neville Longbottom using a “Remembrall”
- Wake up curtains. The curtains could be given a time and aid in an ambient wake up, similar to the Philip’s Hue Lights wake up on alarm function.
- Stopwatch: the opposite of a timer. Once set, the pattern could fade in rather than fade out. The pattern could reflect time passing, rather than counting down.
- The different colours could reflect different weather outside. If the temperature is hotter, the blue could fade away, or vice versa with the pink hues.
Questions to consider for future iterations
- How would one interface with the curtains? Would there be a web app that they could use to indicate the timer? A button, potentiometer, and LCD screen combination for changing the time, or starting, and stopping the process?
- How dense does the pattern need to be to affect the light in the space? If the curtains do not affect the lighting of the space, does the fabric need to be hung like a curtain, or could it be a wall hanging?
- How could the wiring be improved for the patterns? The length of the connections affects the heat generated from the circuit, which would ultimately affect the fading of the pattern. Would using conductive thread and having short connections to multiple power sources be the most effective?
- Would having the curtains alter the user’s position in the room? What if their work station was turned away
The thermochromic pigment is a very accessible and enjoyable technology to explore within soft electronics. The resistive fabric when connected to a circuit has a very similar behaviour to a switch, which when connected to either bespoke interfaces or APIs allows for endless possibilities of applications. Through exploring the concept of time and curtains as an ambient technology I discovered that power management and circuit management are the most concerning factors in setting up a viable product. These mini-experiments are explorations into looking at the possibilities of how one could add thermochromic pigment as apart of their electronics toolkit. Overall the pigment is a useful tool that has lots of applications for creating bespoke experiences embedded in everyday environments.
References and research