EEVblog #653 - Sydney Maker Faire 2014 Highlights

[JoeN]

Anyone know what the technology is at ~ 6:40 where a bright light appears to be "writing" to some sort of phosphorescent cylinder that excites and then radiates light back out for a period of time?  Never seen that before.  Is that just a cylinder made of a phosphorescent material?  Any idea where to get one of those?

[mikeselectricstuff]

Anyone know what the technology is at ~ 6:40 where a bright light appears to be "writing" to some sort of phosphorescent cylinder that excites and then radiates light back out for a period of time?  Never seen that before.  Is that just a cylinder made of a phosphorescent material?  Any idea where to get one of those?

Glow-in-the-dark paint -excited by UV LEDs.

[JoeN]

Anyone know what the technology is at ~ 6:40 where a bright light appears to be "writing" to some sort of phosphorescent cylinder that excites and then radiates light back out for a period of time?  Never seen that before.  Is that just a cylinder made of a phosphorescent material?  Any idea where to get one of those?

Glow-in-the-dark paint -excited by UV LEDs.

I might try a project based on this idea.  Anyone know a specific paint brand they have used that they can recommend?  Can anyone recommend UV LEDs?  Thank you for the information so far.

[alimirjamali]

I might try a project based on this idea.  Anyone know a specific paint brand they have used that they can recommend?  Can anyone recommend UV LEDs?  Thank you for the information so far.

Hi Joe,

We use this material frequently at work. It is available as paint, pigment, vinyl and even recently as filament for 3D printers. I think it could be easier for you to go for vinyl if you want to warp it around a cylinder. We usually buy in bulk quantities from China. You should be able to buy small quantities from e-bay or Amazon. The price varies based on the amount of rare-earth metals added to zinc sulfate copper mix to make it glow longer. Different colors available but yellowish green glows best. Major brands such as 3M or Avery Dennison sale glow-in-the dark vinyl. Marabu-Inks sales Glow-in-the-dark paint for screen printing applications. We have used Marabu-inks, 3M and Avery Dennison.

If you want to create a non-cylindrical shape & you live in north America, TAP Plastics sales pigments which you could mix with their clear casting resin. I have heard good feedback from their customers.

Quality should not be that much important in this application as the glowing effect should not last until the next revolution of cylinder (should be the opposite!).

Ali

[mikeselectricstuff]

Quality should not be that much important in this application as the glowing effect should not last until the next revolution of cylinder (should be the opposite!).

Ali

I have a vague recollection that  with some glow materials, you can "discharge" the glow with different light colours

[alimirjamali]

I have a vague recollection that  with some glow materials, you can "discharge" the glow with different light colours

If my memory serves me well, some  photoluminescent materials could be discharged by temperature. I will check this in our text books and consult with experts at work tomorrow  . We usually do not want to discharge them as we make Exit Signs, Muster Station signs and other photoluminescent signs in places that emergency rechargeable electric signs are not allowed by safety standards.

Even if discharging via heat/different light/electricity would be hard/impossible, it would be easy to PMW UV LEDs during ON phase to assure natural discharge by the next revolution. Piece of cake with micros or CPLDs  .

[alimirjamali]

Referring to my previous post on photoluminescent materials

After talking with colleagues at work, looking into text books and discussing with suppliers; I should say that people in HSE (Health, Safety, Environment protection) do not know a photoluminescent material which could be discharged with heat/electricity/other light or cooling. Either such material does not exist or has no application in HSE field. Maybe in some other industry .

[SeanB]

IIRC IR light can be used to shorten the glow period of some materials. Bright IR illumination stops it glowing. Easiest will probably be to try an IR remote control on a glowing piece and see if it dims when held against it in the dark.

[miguelvp]

The term for turning photoluminescence off is quenching.

Google "photoluminescence thermal quenching" and you'll get some hits.