|Credit: Joshua Edel|
Topics: Optical Physics, Nanotechnology, Quantum Mechanics
Note: My study group is preparing for midterms next week. I give my apologies for what will be an erratic posting schedule. I'm merging two colloquialisms: drinking from fire hoses and eating elephants one bite at a time. I should resume posting normalcy - as far as grad school goes - the 9th of October, until finals week in December.
From last Friday's posting, it's obvious what I thought of the (lack of) humanity pursuing the deaths of millions to give tax cuts for the few. I'm glad for the moment the Affordable Care Act hasn't met the zombie apocalypse. I have no doubt like the pertinacious walking dead, they will try again.
Surface plasmons—collective, light-driven oscillations of electrons in metal—have given us stained glass, flat lenses, and home pregnancy tests. Now they bring us the mirror–window, a liquid mirror whose reflectivity can be tuned, or eliminated altogether, with an applied voltage.
Developed by researchers led by Alexei Kornyshev, Anthony Kucernak, and Joshua Edel at Imperial College London, the device makes use of gold nanoparticles inside a cell filled with two immiscible electrolyte solutions—one aqueous, the other oily. Dispersed throughout one phase or the other, the nanoparticles interact negligibly with light, and the cell is transparent. But when the particles form a dense monolayer at the liquid–liquid interface, their plasmon resonances couple to each other and they become optically reflective.
Now you see this nanoplasmonic mirror. Now you don’t.
A tunable assembly of gold nanoparticles can go from reflective to transparent with the flip of a switch.
Ashley G. Smart, Physics Today