Electrochromatic glass as compared to other smart glass technologies. Electrochromic glass is used primarily for exterior windows while PDLC smart glass can be used for both interior and exterior glass and windows.
Smart Glass Technology Overview
Smart glass film is intended to have the ability to control the
amount of light, and heat, passing through. With a switch of a
button on a wall or smart phone app, the glass can change from
transparent to completely opaque. Unlike blinds, smart windows
are capable of partially blocking light while maintaining a clear
view of what lies behind the window.
Smart glass technologies include electrochromic, photochromic,
suspended particle, and liquid crystal device technologies (PDLC).
While the basic concept behind all smart windows is the same,
they can be made in several different ways, each with a different
method and properties for blocking light. Critical aspects of smart
glass include material costs, installation costs, electricity costs and
durability, as well as functional features such as the speed of
control, possibilities for dimming, and the degree of transparency.
• Interior Glass: Control the amount of privacy, light and heat
that enters a space manually or automatically
Switch instantly or dim anywhere in between
No need for blinds or curtains
Enable privacy while retaining natural light
• Exterior Glass
Privacy without the need for curtains or blinds
98% UV protection
40% solar reduction
• Rear projection
Residential home theater display
Corporate / retail display
Why Use Smart Glass?
Types of Smart Glass
Liquid Crystal (PDLC)
Passive Smart Glass:
Responds to non-electrical stimuli
(heat, UV). Cannot be manually
Active Smart Glass:
Responds to an electrical stimulus &
and is controllable manually or
Various Terms for Smart Glass
Self Tinting Windows
Clear to Opaque Glass
Liquid Crystal Glass
Active Smart Glass
• Suspended particle device (SPD)
• Polymer dispersed liquid crystal (PDLC)
• Typically used for solar control on exterior glass.
• The visible light transmission in the darkest state can be less than
3%. The resulting shading has limited privacy function as it can
still be seen through.
• Consists of two glass panes with several layers sandwiched in between.
• It works by passing low-voltage electrical charges across a
microscopically thin, clear conductive coating on the glass surface,
which activates electrochromic layers that change color from clear
• The electric current can be activated manually or by sensors which
react to light intensity.
• One advantage of the electrochromic smart window is that it only
requires electricity to change its opacity, but not to maintain a
• The switching speed of electrochromic glass is very slow and varies
depending upon the size of the panel (larger panels typically take many
minutes to switch). The consistency of tint changes also varies, with
larger panels sometimes exhibiting tint changes that begin at the
glazing’s outer edges and then move inward (known as the “iris
Active: Suspended Particle Device
In suspended particle devices (SPDs), a thin film laminate of rod-like nano-scale
particles is suspended in a liquid and placed between two pieces of glass or
plastic, or attached to one layer. When no voltage is applied, the suspended
particles are randomly organized, thus blocking and absorbing light. When voltage
is applied, the suspended particles align and let light pass. Varying the voltage of
the film varies the orientation of the suspended particles, thereby regulating the
tint of the glazing and the amount of light transmitted. The visible light
transmission at the darkest state of SPD glazing is around 0.5% and the process
takes one to three seconds after power is applied, regardless of the size of the
window. The resulting dark blue shading blocks light and provides only partial
Active: Suspended Particle Device
Ideal for such light control applications as
skylights, auto glass, sunroofs, aircraft
windows, and marine windows and portholes.
Active: Polymer Dispersed Liquid Crystals
Polymer dispersed liquid crystal is simply micro droplets of liquid crystals
encapsulated in a polymer matrix. The liquid crystals respond to an electrical
charge. In a static state, the liquid crystal molecules remain in a randomized
configuration that refracts the light that enters the mixture, making it appear
opaque. When electricity is applied, the molecules line up the direction of the
electric field, allowing light to pass through what is now essentially a
transparent surface. When electrical charge is deactivated, liquid crystal
droplets again become randomly oriented, the incoming light is again heavily
scattered and does not pass through in a straightforward manner, resulting in
fully blocked images.
Liquid crystal applications are a familiar technology for numeric and flat panel
displays. Liquid crystal display, or LCD, is the most popular flat panel display
technology, seen in portable computers, cell phones, calculators, digital clocks,
gas pumps, and watches, etc. In LCD, applied electricity changes the shape of
liquid crystals to allow light to pass through individual elements, thus forming
images, figures, and numbers on the displays.
• Can be used for interior or exterior glass applications.
• Switches from opaque (milky white or gray) to clear in less than a second.
• Can run on standard 110-volt AC.
• Available in a self-adhesive switchable film that can be applied to existing
• Provides total privacy in its opaque state (cannot be seen through).
• Used for exterior glass applications, for solar control.
• Not used for interior privacy
• Long transition time from clear to opaque. Larger windows can take five to
• New glass must be installed; no film option for existing glass.
• Not used for privacy as you can still see through it in its dark (tinted) state.
PDLC vs. Electrochromic Technology
Switchable glass and film are the ideal electric privacy glass
solution for bathrooms, kitchens, room partitions, windows
and skylights. The technology provides unprecedented
control over the amount of heat and light that enters a
PDLC: Door Application
• Hinged doors
• Sliding doors
Case Study – Corporate Conference Room
Requirements: Promote open collaborative work
environment, maintain views when privacy not required and
preserve natural light into the office.
Solution: PDCL smart glass installed for privacy vs. blinds to
maintain natural light in the rest of the office space and
sweeping views of the city.
Types of PDLC Switchable Glass
• Laminated Switchable Glass
– Typically used for new construction projects. Switchable
film is sandwiched between two sheets of glass and two
sheets of conductive interlayer. Glass can be made to any
thickness (i.e. 10mm) and specification required (i.e.
tempered, low-e, etc.)
• Adhesive Switchable Film
– Typically used for retrofit applications. Switchable film has
an adhesive side that is dry applied to the surface of any
glass (similar to a smart phone cover). The film is scratch
resistant and easy to install in the field.
Laminated PDLC Switchable Glass
The layer containing indium tin oxide (ITO) conducts the electricity
that stimulates the liquid crystals.
Adhesive Switchable Film applies to any existing or new smooth glass
surface. Any wall switch, home automation or smart phone app can
change the film from being clear to frosted (opaque) or dim in between.
Self-Adhesive FilmAdhesive Switchable Film
• Blocks 99% of UV rays which cause damage and discoloration of interior
walls, carpets, and furnishings
• In its opaque state, PDLC smart glass can reduce solar heat gain by up
to 40%. The reduced heat gain in hot months helps keep the interior
cooler, thus requiring less air conditioning producing increased
occupant comfort, and providing cost savings.
Privacy, Occupant Comfort, Energy Use Reduction with
Privacy, Occupant Comfort, Energy Use
Reduction with PDLC Technology
PDLC – Interior Applications
• Creates flexible use of space
• Creates privacy when needed
• Compatible with home and
building automation systems
• Rear projectable /Display
PDLC – Interior Case Study
Part time guest room
While this New York City
apartment had enough
space to section off a 100-
sq. ft. portion for a guest
room, the owners did not
want to lose half the light
and views by adding solid
walls. Their architect came
up with a unique solution.
PDLC – Interior Case Study
By adding solid walls half of the light and views that flooded the living room,
kitchen, and dining areas deep into the space would be blocked by any new
walls. That seemed too high a price to pay.
The architect, Andrew Mikhael, came up with the idea of designing half walls
of smart glass that could transform from clear to opaque as needs dictated.
PDLC – Interior Case Study
Inside the room, with the switchable glass set to opaque, enough privacy is
created for a guest to feel comfortable in the space. When no guest is visiting,
or if the space transforms to a nursery and the parents want to keep an eye
on the baby, the windows can be switched to clear.
PDLC – Hotel Bathroom
With PDLC smart glass, sections of a bathroom can have privacy or openness
as needed, without blocking all the natural light. In this hotel application, the
occupant can enjoy the openness of the room and beautiful tile work of the
bathroom, and switch to privacy as need.
Switchable glass installed for separated or
opened space between basin and bathroom.
PDLC- Residential Bathroom
PDLC – Retail Case Study
To grab the attention of passing traffic, this
retailer uses smart glass that switches from
clear to opaque in patterns. The attention
from passersby greatly increases in-store
traffic. Additionally, the panels can be used
in the evening to project HD quality video,
creating a video advertising experience that
contributes to branding and thus greater in-
PDLC Switchable Glass offers a privacy solution while
maintaining a sterile environment in hospitals, clinical
environments and healthcare facilities.
* Curtains are not sterile and can harbor bacteria
PDCL – Case Study Healthcare
About Glass Apps
Glass Apps is the leading providing of Switchable Glass and Film which
changes from clear and opaque states on demand and is also dimmable,
therefore, providing unprecedented control over the amount of light,
privacy and heat that enters a space.
Glass Apps smart glass technology has been proven in the market for over