[soiboi soft] developed a dot-matrix display that operates with shadows created by the vacuum-formed cavities behind a flexible silicone sheet. In the first trial, eight control channels consisting of four row and four column channels were used for a 16-pixel display. Thanks to pneumatic transistors, the pixels retained their states even when pressed by hand; with suitable circuitry, the display can be converted into a touch surface.
During scaling up to 64 pixels, the bending of 3D-printed parts caused sealing problems. The parts were corrected by pressing them against a flat glass surface in a vacuum bag and heat-treating them at 60 degrees Celsius for several hours. In its final form, the display could show letters, numbers and animations; the games Pong and Snake were also run.
Why it matters
This work presents a different approach to implementing a display by addressing the concept through flexible material, vacuum and pneumatic logic instead of electronic components. The fact that the pixels retain their state after pressure is applied allows the image to be produced not only visually but also through physical interaction; the ability to convert it into a touch surface broadens the ways this approach can be used. However, the sealing problems observed when moving to 64 pixels show that manufacturing precision is as decisive as design in scaling up the system. While the ability to display letters, numbers and games demonstrates that basic functions are possible, whether the same reliability and ease of manufacturing can be maintained at higher resolution remains an open question.