July 22, 2024

Flex Tech

Innovation in Every Curve

Strong, 5x stretchable ‘glassy gels’ pave way for flexible electronics

Researchers have created a material that is both hard and stretchy. Sounds impossible, right? Well, that’s exactly what glassy gels are.

Researchers from North Carolina State University created this new class of materials, which contains more than 50% liquid. 

The creators highlight that the manufacturing process of glassy gels is straightforward and has the potential to create flexible electronics and wearable devices. 

“Creating glassy gels is a simple process that can be done by curing it in any type of mold or by 3D printing it,” said Michael Dickey, corresponding author of this new study paper, in the press release.

Glassy gels are hard and stretchable

Gels and glassy polymers have typically been seen as completely different. Gels, like contact lenses, are soft and contain a lot of liquid. On the other hand, water bottles and airplane windows are made of glassy polymers, which are hard and brittle.

The glassy gels combine the best of both worlds. The material is incredibly strong and hard, but it can stretch up to five times its original length without breaking. Plus, they can be heated back to their original shape. 

Dickey explained: “What’s more, once the material has been stretched, you can get it to return to its original shape by applying heat. In addition, the surface of the glassy gels is highly adhesive, which is unusual for hard materials.” 

Development of the material

The secret lies in a special combination of ingredients. Scientists begin with “liquid precursors” of glassy polymers and combine them with an ionic liquid, a solvent similar to water but composed entirely of ions or charged particles.

This mixture is then put into a mold and cured under UV light. Finally, they remove the mold, revealing the polished glassy gel.

“In glassy gels, the solvent pushes the molecular chains in the polymer apart, which allows it to be stretchable like a gel. However, the ions in the solvent are strongly attracted to the polymer, which prevents the polymer chains from moving. The inability of chains to move is what makes it glassy. The end result is that the material is hard due to the attractive forces, but is still capable of stretching due to the extra spacing,” explained Dickey. 

Interestingly, glassy gels are over 50% liquid. This liquid component can contain dissolved salts or other ionic compounds, which act like the charged particles needed for electricity conduction. Their conductivity makes them ideal for new types of flexible electronics.

Plastics lack these freely moving charged particles within their structure, which makes them not ideal for devices.

During material testing, the researchers demonstrated a remarkable property of glassy gels: their resistance to drying despite containing 50-60% liquid.

“Considering the number of unique properties they possess, we’re optimistic that these materials will be useful,” mentioned Meixiang Wang, co-lead author of the paper, in the press release. 

The study findings have been published in the journal Nature. 


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Mrigakshi Dixit Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her professional experience encompasses both broadcast and digital media, enabling her to learn a variety of storytelling formats. Her work has been featured in well-known publications including Nature India, Supercluster, and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.