In a world drowning in OLED panels and refresh rate wars, someone decided to build a display that inflates.
The Soiboi Soft 3D is a pneumatic 7-segment display created by a maker who goes by the handle smdmunmun. Instead of LEDs or LCD segments, it uses small air-driven bladders that physically expand and contract to form numbers. The result is somewhere between a novelty clock and a statement about what displays could be if we stopped optimizing for the same metrics everyone else is chasing.
How It Works
Each segment of the display is a silicone bladder connected to a small air system. When inflated, the segment becomes visible; when deflated, it recedes into the surface. The transitions are slow compared to electronic displays, but that's part of the appeal. The whole thing breathes.
The project runs on an Arduino controlling a series of solenoid valves that manage airflow to each segment. It's a straightforward setup in principle, though the execution required considerable work getting the bladders to inflate evenly and the timing to stay consistent.
The Soiboi Soft 3D builds on a tradition of physical computing projects that prioritize tactile experience over raw performance. It shares DNA with flip-dot displays, split-flap boards, and other mechanical information systems that have largely been replaced by screens. Those older technologies persist in transit stations and airports partly because they're reliable, but also because people genuinely enjoy watching them.
Why Pneumatics?
Air-driven displays sound absurd until you consider their advantages. They can be scaled up without the cost explosion of large LED arrays. They're inherently soft, which makes them safer in environments where people might interact with them directly. And they offer a kind of presence that flat screens struggle to match.
Soft robotics researchers have been exploring pneumatic actuation for years, mostly in contexts like humanoid robotics and prosthetics. The Soiboi Soft 3D applies that same principle to information display, which opens up interesting possibilities for signage, art installations, and accessibility interfaces.
The Limits
Pneumatic displays won't replace your phone screen. Refresh rates are measured in hundreds of milliseconds rather than microseconds. The air system adds complexity and potential failure points. And resolution is constrained by the physical size of each bladder segment.
But those constraints are also what make the project interesting. In an industry obsessed with miniaturization and speed, there's something genuinely refreshing about a display that moves at human pace and invites you to touch it.
The Soiboi Soft 3D is available as an open-source project on Hackster.io, with full build instructions and CAD files. For anyone tired of staring at rectangles, it's worth a look.
