New "smart materials" change color and transparency when stretched

Marine animals such as squid, squid, and octopus can change color by selectively contracting muscles. This incredible feature has also inspired scientists' imaginations. According to foreign media reports, researchers at the University of Connecticut have just created a new type of material that can change color and transparency under mechanical stress. They are collectively referred to as "mechanocromics" materials and can be used in fields ranging from smart doors and windows to device physical encryption.

This material can be used in areas such as smart doors and windows and device physical encryption.

Due to the mid-range interaction between molecules, the polymer can change its reflection/absorption properties under shear/stretch/friction forces.

A team led by Dr Luyi Sun, an associate professor of chemistry at the school, has used this property to create four different types of mechanical color change devices.

This "mechanical color change" device turns yellow from green to orange when tensile strength increases.

The first type of device can change the transparency (TCM) under the influence of force - it becomes more transparent when stretched and becomes opaque when released - and this change is reversible.

The researchers pointed out that this type of device can be used for smart windows, which can be switched between transparent and opaque with only a slight pull.

Encrypted "mechanical color change" devices can "reversely reveal" or hide any desired pattern or text.

The second type is "Mechanical Luminescence" (LM), which emits dense fluorescence when stretched; the third type is "Mechanical Discoloration" (CAM), which can change from green to yellow at different strengths. Turn orange again.

The fourth type is "Display Encryption" (EM), which is a simple bilayer system, a rigid film + soft substrate that can reversibly display and hide any pattern or text.