The Science Behind Smart Glass

Summary

This video explores the science behind smart glass technology, which can switch between clear and opaque states with the press of a button. Utilizing polymer-dispersed liquid crystals, these materials exhibit properties of both liquids and crystals, aligning under electric current to control light transmission. Smart glass has practical applications in privacy, aviation, and energy efficiency, potentially reducing cooling costs and UV damage to interiors.

Takeaways

• 🤓 The smart glass technology involves a film that can switch between clear and opaque states with the touch of a button.
• 🔬 The film consists of a plastic polymer with tiny holes filled with liquid crystals, similar to the structure of Swiss cheese.
• 🌐 A micron is one millionth of a meter, and the holes in the film are about 0.3 to 3 microns in size.
• 💡 When no current is applied, the liquid crystals scatter light, making the glass appear opaque due to their random orientation.
• 🌠 Applying an electric current aligns the liquid crystals, allowing light to pass through unscattered, making the glass clear.
• 🧪 Liquid crystals have properties of both liquids and crystals, being fluid yet capable of orientation like a crystal.
• 🔎 The index of refraction of liquid crystals changes with their orientation, affecting how light travels through them.
• 🌈 The alignment of liquid crystals with the electric current matches their index of refraction to the polymer, allowing light to pass straight through.
• 🏢 Smart glass is used for privacy, allowing control over visibility in spaces like offices.
• ✈️ Boeing has incorporated smart glass in their 787 Dreamliner airplanes to control light levels, replacing traditional sunshades.
• 💰 Smart glass can reduce cooling costs by blocking sunlight, potentially saving up to 20 percent on electrical costs and blocking 99% of UV rays.

Q & A

What is the primary function of smart glass?

Smart glass can change from clear to opaque and back again with the touch of a button, primarily through the use of polymer dispersed liquid crystals.

What are the tiny holes in the smart glass filled with?

The tiny holes in the smart glass are filled with liquid crystals, which are responsible for the opacity and clarity changes.

What is the significance of the micron measurement in the context of smart glass?

A micron is one millionth of a meter, and the tiny holes in the smart glass are about 0.3 to 3 microns, indicating the microscopic scale of the technology involved.

How do the liquid crystals affect the opacity of the smart glass when no current is running?

When no current is running, the liquid crystals are randomly oriented inside the holes, scattering light and making the glass appear opaque.

What happens to the liquid crystals when an electric current is applied?

When an electric current is applied, the liquid crystals align in the same direction, allowing light to pass through unscattered, making the glass clear.

What dual properties do liquid crystals possess?

Liquid crystals have properties of both liquids and crystals, being fluid and able to move like a liquid but also having the ability to be arranged in a certain orientation like a crystal.

Why is the index of refraction important in the functioning of smart glass?

The index of refraction determines how fast light travels through a material. In smart glass, when the liquid crystals are randomly oriented, their index of refraction does not match the polymer, causing light to bend and scatter, making the glass opaque. When aligned, their index matches the polymer, allowing light to pass straight through.

What is the role of antiotropic properties in liquid crystals used in smart glass?

Antiotropic properties mean that the properties of the liquid crystals change with their orientation. This is crucial in smart glass as it allows the liquid crystals to change from scattering light to allowing it to pass through when aligned by an electric current.

What are some real-life applications of smart glass?

Smart glass is used for privacy in offices, in Boeing 787 Dreamliner airplanes to control light levels, and to reduce cooling costs by blocking sunlight and reducing electrical costs, as well as blocking UV rays to protect interiors.

How does smart glass help in reducing cooling costs in buildings?

Smart glass reduces the amount of sunlight entering a building when not in use, which can save up to 20 percent on electrical costs and also blocks 99% of UV rays that can degrade carpets and furniture.