One of my favourite and simplist projects at Ars Electronica was Aram Bartholl ‘s Random Screen.

“Random Screen” is a mechanical thermo dynamic display which does not rely on any electricity.

Each of the 12 by 12 cm pixels is an individual entity. A tee candle lights and controls each pixel. The rising heat of the candle turns a modified beer can which turns the pixel on and off. Each pixel has its own frequence. The more bright a candle shines the faster is the rotaion of the can.

His other project presented at Ars Electronica was Paperpixel

Paper Pixels is a 30 inch, 8 x 8 pixel, manually controlled screen. Each of the 64 pixels is illuminated steadily by a light bulb. Apart from the light bulbs, no further electronic parts are used. The display is controlled by a long paper strip – the data medium – into which have been punched holes arranged along 64 rows or “tracks“. As the strip is pulled by hand between the light sources and the pixels, these holes control each of the pixels individually. When a hole passes directly beneath a pixel it allows light through, illuminating the corresponding pixel.

 

The ends of the paper strip is are joined so it forms an endless loop which passes around two cylindrical rollers fixed to each end of the display unit. In order that the 64 pixels can be controlled individually, and so that a hole in the paper doesn’t spread through each pixel in a pixel row, the light bulbs are arranged in tilted rows along the direction of the paper’s movement. Exactly the same order is used in the accompanying programming board. 64 steel pens as blanking are fixed in an MDF board, through which the strip of paper to be programmed is pulled. The desired pixels can be activated frame for frame, or the holes can be punched in the paper manually. The diameter of a hole is 6mm. For the next frame, the 54 cm wide strip of paper is moved along about 1cm.

The paper strip formed as an endless loop is approximately 3 m long which allows a programmable capacity of approximately 300 frames. The number of frames per second (fps) is determined by the speed at which the paper is pulled through the screen. The duration of the loop for an 8 x 8 pixel display at 10 fps is approximately 30 seconds.