No, that glowing pickle isn’t a promotion for rave night at Katz’s, it’s a demonstration for how your TV works. In this ingenious twist on the classic potato clock, MIT professor Vladimir Bulovic transforms a humble full sour into a giant OLED pixel for our learning pleasure.
OLEDs are nothing more than an electrically active organic material sandwiched between an anode (a electron-expelling electrode) and a cathode (an electron-receiving electrode). When an electric current runs through the system, the anode sends electrons to the cathode, creating a current through the organic material. This charges the organic material, and when positive and negative charges hit the same molecule, it releases a photon, which we perceive as glowing.
In this case, the acidic pickle is the electrically charged organic material. By running a current through it, the pickle transforms into a giant pixel, or single light source. Bulovic could arrange millions of pickles into a grid, add some color filters, and build himself a giant kosher flat-screen TV.
Naturally, the actual OLED pixels used in televisions are far smaller and more efficient than the luminescent cucumber in the video. However, they are much less tasty.