Active Smart Glass

. What are smart glass

.Types of smart glass

. Electrochromic devices (EC)

. suspended particle devices (SPD)

. Polymer dispersed liquid crystal devices (PDLC)

. The benefits of smart glass

.Application

Presented by

Mohammed Nasr ElDin Ibrahim Abd Elhamid

What are Smart Windows?Smart Windows are windows which use a glazing material to control the amount of light that is allowed to pass through the glass panes. The glazing material is often called “switchable

glazing”.

These materials change their optical behaviour with application of electrical voltage.

Types Of Smart Glass

Electrochromic Glass

Electrochromic windows centred around special materials that have electrochromic properties .

‘Electrochromic’ describes materials that can change color when energized by an electrical current.

Electrochromic windows darken when voltage is added and are transparent when voltage is taken away.

How Does It Work?

Electrochromic Glass The basic working principle involves lithium ions

(positively charged lithium atoms—with missing electrons) that migrate back and forth between the two electrodes through the separator.

When the glass is clear, the lithium ions reside in the innermost electrode.

When a small voltage is applied to the electrodes, the ions migrate through the separator to the outermost electrode , where they scatter away most of the incoming light and turn the glass opaque. 

Electrochromic Glass They remain there all by themselves until

the voltage is reversed, causing them to move back so the glass turns transparent once again.

Suspended Particle Devices (SPD)

SPD window consists of several layers: Two panels of glass or plastic. Conductive material - used to coat the

panes of glass. Suspended particle devices - millions of

these black particles are placed between the two panes of glass.

Liquid suspension or film - allows the particles to float freely between the glass.

Control device - automatic or manual.

Suspended Particle Devices (SPD)

Suspended Particle Devices (SPD) In suspended particle devices (SPD), a thin

film laminate of rod-like particles suspended in a fluid is placed between two glass or plastic layers, or attached to one layer.

When the power supply is switched on, the rod shaped suspended particle molecules align, light passes through and the SPD Smart Glass panel clears.

Suspended Particle Devices (SPD) When the power supply is switched off the

rod shaped suspended particle molecules are randomly oriented blocking light and the glass panel looks dark (opaque).

The SPD Smart Glass when becomes dark can blocking up to 99.4% of light. SPD Smart Glass protect from damaging UV when on or off.

Polymer Dispersed Liquid Crystal Devices (PDLC) Polymer dispersed liquid crystal is simply

micro droplets of liquid crystals encapsulated in a polymer.

The liquid mix of polymer and liquid crystals is placed between two layers of glass that includes a thin layer of a transparent, conductive material.

With no applied voltage, the liquid crystal molecules remain in a randomized configuration that refracts the light that enters the mixture, making it appear opaque.

Polymer Dispersed Liquid Crystal Devices (PDLC)

This results in the translucent, "milky white" appearance.

.

Polymer Dispersed Liquid Crystal Devices (PDLC) When a voltage is applied to the

electrodes, the electric field formed between the two transparent electrodes on the glass.

The molecules line up the direction of the electric field, allowing light to pass through what is now essentially a transparent surface.

The degree of transparency can be controlled by the applied voltage.

Polymer Dispersed Liquid Crystal Devices (PDLC)

Comparison Between The Three Different Kinds Of Switchable Glass (EC,SPD,PDLC)

The Benefits Of Smart Glass

control of light. Energy Saving. Ambient temperature control. Protecting skin from damaging UV rays. Low working voltage. Long life – tested to in excess of 100,000

cycles.

APPLICATIONS

Conference rooms Intensive-care areas Building, hotels and offices

References www.helwan.edu.eg/chinese

/wp-content/uploads/2013/08/1-4-8.pdf

http://www.glass-apps.com/

THANK YOU