FlexLED Is A Unique Take On Persistence Of Vision

Many hackers have experimented with the persistence of vision effect. Whip around a bunch of LEDs, flash them at just the right times, and it’s possible to make images to appear to hang in the air. There’s plenty of ways to do this, whether by manually shaking the LEDs by hand, spinning them around, or even putting them on your bike wheels. [Carl Bugeja] went a different route, taking advantage of the possibilities created by flex PCBs.

[Carl]’s project goes by the name FlexLED. This aptly describes the build, which, in prototype form, mounts a single LED on the end of a flex PCB. The PCB itself has a pattern of traces creating a coil, which enable it to interact with magnetic fields more strongly. By passing the right current through the coil, the flexible PCB can be made to flap up and down, moving the LED on the end at a rapid rate. By then controlling the flashing of the LED, it’s possible to create a persistence of vision effect.

Currently fitted with only one LED, capable of 3 colors, the visual display of the FlexLED is somewhat limited. However, [Carl] reports the effect is more impressive in person than on camera, and is already working on plans to scale up the project to a multi-LED diplay.

POV technology can do some pretty impressive things – even volumetric displays are possible. If you’re working on something yourself, be sure to let us know. Video after the break.

 

10 thoughts on “FlexLED Is A Unique Take On Persistence Of Vision

  1. For those that haven’t heard of [Carl] before, I highly encourage you to watch/subscribe to his channel. Interesting content, educational, and astonishingly high video quality/production values for a ~10k subscriber channel!

  2. So seems like he could easily do two directions like x and y, maybe with a little mirrors instead and then thereby make sort of a laser light show galvos out of it? Maybe even a cheap 3d resin printer ala the defunct peachy printer only hopefully without the defunct part?

    1. Wow impressive, thanks for the link!
      Do you know how the vibration can be correctly transmitted from one end to the other of the fiberoptic ribbon?
      They do not explain this and it seem to me to be the most complex and limiting part of the idea haha

      1. In case it’s not clear, only the very tip (a few millimeters) of the fiberoptic ribbon oscillates (vibrates). Without going back to look at the original material, my recollection (from 3+ decades ago!) is that there is a tiny magnet glued near that tip. The tip oscillates at the resonant frequency of the fiber, like a tuning fork, and the magnet nudges it at that resonant frequency, driven by a small (stationary) coil: just about the reverse of how [Carl] does it here. I’m not sure how they get the phase correct and stable. That’s the part I found difficult when building things like this.

  3. Looks like a good start on what’s needed for a super high speed LASER deflector for light shows. LASER vector arcade games without having the corners rounded off due to galvanometers being unable to move quite fast enough.

  4. There use to be paddle-mounted LED displays that could be programmed to display a message as the paddle was swung. I saw them in use by parking attendants. There was only a single row of LEDs. The trick was using an accelerometer to change the LEDs at just the right speed, so that persistence of vision made the message appear to hang in the air.

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