Transparent surfaces that become opaque

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
7 replies · 3K views · last reply
LightningInAJar
Messages
289
Reaction score
38
TL;DR
Surfaces that change transparency.
Are there any materials that go from transparent to opaque when a bright light is shined on it? In particular I would like something that acts like a window until I project a movie onto it and then is opaque in the regions where the light hits it at certain levels of brightness.
 
Engineering news on Phys.org
LightningInAJar said:
Are there any materials that go from transparent to opaque when a bright light is shined on it? In particular I would like something that acts like a window until I project a movie onto it and then is opaque in the regions where the light hits it at certain levels of brightness.
If sunshine falls on the window, or it is a bright day, the window will become opaque.
No projector can compete with sunlight.
Maybe an LCD window is needed with a separate control.
 
  • Informative
Likes   Reactions: Keith_McClary
You can also get glass which becomes opaque when you pass a current through it.

Glass double doors in a hospital corridor leading into a bright room with medical equipment, including a hospital bed and monitoring devices, with frosted glass panels beside the doors.
Pair of double glass doors with vertical metal pull handles in a corridor, the glass appearing frosted or milky white, flanked by similar frosted glass panels.


https://www.smartglassinternational.com/electric-switchable-glass/
 
Baluncore said:
If sunshine falls on the window, or it is a bright day, the window will become opaque.
No projector can compete with sunlight.
Maybe an LCD window is needed with a separate control.
I would not use it in sunlight.
 
Jarvis323 said:
You can also get glass which becomes opaque when you pass a current through it.
Erm. Does this means that these will switch transparent in case of a power outage?

Just asking :doh:
 
Rive said:
Erm. Does this means that these will switch transparent in case of a power outage?
Smart glass does not have “a current pass through it” as that would be very inefficient. Switchable glass has a liquid crystal film, between transparent conductive layers, within the laminate that change optical characteristics when subjected to an electric field.
The glass becomes transparent only when a voltage is applied.
Loss of power does not lead to loss of dignity.
 
  • Like
Likes   Reactions: Rive