PDLC in one paragraph
PDLC stands for Polymer Dispersed Liquid Crystal. Droplets of liquid crystal are suspended in a polymer matrix, sandwiched between two transparent conductive layers (usually ITO-coated PET) and laminated between protective films.
With no power, the crystals point in random directions. Light entering the film hits thousands of differently-oriented droplets, refracts at each boundary and scatters — the film looks white and translucent. Apply voltage and an electric field forms across the layer, aligning every droplet along the same axis. The refractive index now matches the surrounding polymer, light passes straight through, and the film goes clear.
Electrical requirements
- Supply: typically 48-65V AC at 50/60 Hz via a dedicated transformer or driver, converted from standard mains
- Wiring: two low-voltage bus bar leads exit the film edge and must be concealed in the frame, mullion or wall
- Control: wall switch, dimmer-style driver, remote, occupancy sensor, or building automation via relay or dry contact
- Never DC: continuous DC degrades PDLC and shortens film life; the driver must supply AC
- The wiring must be planned before the glass or frame detailing is finalized — this is the part that surprises retrofit projects
Switching speed and power consumption
Switching is effectively instantaneous — typically under 100 milliseconds in each direction, so it reads as instant to the eye.
Power draw is modest and continuous only while clear: on the order of 4-8 watts per square metre. A 3 m² conference-room partition therefore draws roughly the same as a small LED bulb while transparent, and nothing while opaque. Since most installations are opaque by default and clear only when in use, annual energy cost is negligible.
Smart film vs electrochromic glass
PDLC switches between clear and opaque — it manages privacy. It does not meaningfully tint or control solar heat.
Electrochromic glass switches between clear and tinted over several minutes, using an electrochemical reaction to change light and heat transmission. It manages daylight and solar gain, and it never becomes private.
They solve different problems, and projects sometimes use both: electrochromic on the exterior facade for glare and heat, PDLC on interior partitions for privacy.
Retrofit film vs laminated smart glass
Self-adhesive PDLC film can be applied to existing glass, which makes it the only option for occupied buildings. Edge quality and wiring concealment are the two things that separate a professional retrofit from a visible one.
Laminated PDLC glass has the film encapsulated inside a new glazing unit at the factory. It looks cleaner and lasts longer because the film is sealed from moisture and handling, but it requires replacing the glass.
Cost and lifespan
Smart film is the most expensive film category by a wide margin — an order of magnitude above premium solar film per square foot, before the electrical work. Budget for a licensed electrician, driver hardware, and control integration in addition to the film itself.
Service life is typically quoted around 10 years or more for quality laminated product used normally. The most common failure causes are moisture at the edges, DC supply, and physical damage to the bus bar area — all installation-quality issues.
Where it works best
- Conference rooms and executive offices needing on-demand privacy without blinds
- Medical exam rooms and clinic partitions where cleanability matters
- Retail display windows that switch between showcase and projection surface
- Residential bathrooms, shower enclosures and street-facing glass
- Any application where blinds would collect dust or violate an infection-control protocol
Related reading and services
Frequently Asked Questions
Does smart film provide privacy at night?
Yes, and this is a key advantage over reflective film. In its opaque state PDLC scatters light in both directions regardless of which side is brighter, so it works identically at night.
How much power does smart film use?
Roughly 4-8 watts per square metre while clear, and zero while opaque. A typical conference-room partition uses about as much as a small LED bulb during the hours it is transparent.
Can smart film be installed on existing windows?
Yes. Self-adhesive PDLC film retrofits onto existing glass, but it needs a concealed low-voltage supply, so an electrician and a wiring plan are part of every project.
Does smart film block heat?
Not appreciably. PDLC controls privacy, not solar gain. If heat and glare are also concerns, pair it with a solar-control film or specify electrochromic glazing for the exterior facade.
What happens to smart film during a power outage?
It reverts to its unpowered state — opaque. Privacy is preserved by default, which is the desirable failure mode for exam rooms and bathrooms.
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