Check out the product pictured above. The title of the article surely has given you the hint as to what am I here to talk about. This is the lovely LED matrix quilt that was created by Katie Dektar, a Stanford University undergraduate majoring in Biomedical Computation. It’s not an ordinary quilt that we find in every second home we drop in. The quilt is comes with 64 hand-sewn LEDs and is controlled by a Lilypad Arduino.
Well, the designer talks in length about the blanket. Wanna know the step wise procedure she followed to come up with the techie and cool blanket? Read on! To come up with the flickering LEDs look like trapped fireflies in a beautiful way she worked with immense dedication and did a great job.
Firstly she sewed the rows of the matrix by machine by putting the conductive thread in the bobbin. They all come together in the corner where they will attach to the Lilypad Arduino. She then sewed on 64 LEDs by hand, which took quite a good time. Using the embroidery hoop made this 10x easier. Each LED is at the intersection of 1 row and 1 column, and is turned on when that row and column are set to the appropriate low and high voltages (~ 5V). The vetical thread is just plain cotton thread and the conductive trace is on the backside. By jumping the row over the conductive column she made sure there are no short circuits. The resistors were put at the end of each row to limit the current across that row. This resistance of the conductive thread is nontrivial at these distances. There are about 80 ohms of resistance difference from the first LED in a row to the last. These resistors made sure not to burn out the first LED. Also, the female snaps were sewed to attach the lilypad arduino that’s attached to the corresponding male snaps.
The snaps each on one row or column of the quilt matrix allows the arduino to control each light individually. In the quest not to break the conductive thread when snaps are unsnapped snaps, the designer reinforced the conductive thread with normal grey thread. Once the matrix was complete, it was tested with the lilypad and a basic random walk amongst the LEDs.
There after the quilt was quilted and It was like a LED matrix sandwich-back layer of purple, LED matrix layer, layer of cotton batting, front layer of purple and orange panels.
Don’t take the quilt to be hard if its endowed with LEDs. The cool LED quilt is indeed deformable and soft!