How does PDLC smart glass work?
With no applied voltage, the liquid crystals are randomly oriented and scatter the light which enters. When an electrical signal is applied, the liquid crystals orient themselves parallel to each other, allowing light through.
Does PDLC smart glass conduct electricity?
No, the internal PDLC layer is plastic and does not conduct electricity, since it is electrically insulated. Rather, it behaves more like a capacitor, where the applied signal alternates between positive and negative voltages at the plates of the capacitor, causing an alternating electric field throughout the PDLC dielectric, which is what aligns the liquid crystals with the frequency of the signal (normally 50 Hz or 60 Hz).
Are the only states of PDLC just ON and OFF?
No, the transmittance (level of transparency) of the PDLC can be varied from 0% in the OFF state up to any value you want until you reach the maximum transmittance (normally 70% or 80%). This is done by simply altering the voltage from 0 VAC up to 70VAC, which is typically the maximum recommended voltage. This can be done electrically with a variable isolating transformer, or electronically with a switched-mode smart glass dimmer.
How to make smart glass?
How to make smart glass?
Why does PDLC glass scatter light?
The liquid crystals change their refractive index in relation to the isotropically transparent polymer in which they are immersed, thereby creating multiple step boundaries throughout the PDLC.
It is this change in refractive index at each boundary which causes light to change course. Since the PDLC material contains millions of liquid crystals, each with a boundary facing a slightly different way, the light is scattered in many directions.
The net effect is to hide whatever is behind the PDLC smart glass.