A group of researchers has developed a new material that is not only flexible but also completely sealed from gases and liquids—a typical drawback of such materials. This material holds promise for use in the production of flexible batteries or wearable electronics.
Materials development often involves a tradeoff between certain properties. If you need a material that can block gases and liquids, you need a hard, rigid material. On the other hand, if you need a material with some flexibility, you must accept that at least some of the gas or liquid will be able to pass through.
However, in a new study, scientists from North Carolina State University (NCSU) have developed a new material that possesses both of these properties. The key to their success lies in a unique alloy called eutectic gallium-indium alloy (EGaIn), which consists of two soft metals—gallium, indium, and gallium—that is liquid at room temperature. EGaIn has proven itself to be a versatile material—in recent years, it has been used in carbon capture catalysts, soluble implants, and stretchable and flexible electronic devices.
To obtain this new material, the research team embedded a thin layer of EGaIn in a flexible polymer. A series of tiny glass beads were positioned within the polymer to prevent the EGaIn from clumping together at any one point. This makes the new material a flexible and elastic polymer, whose liquid metal core effectively prevents the passage of gases and liquids.
To test the material’s effectiveness, the research team measured whether the liquid metal would evaporate over time and whether oxygen would escape from a sealed container made of the polymer. In both cases, no liquid or gas loss was detected, indicating the material’s effectiveness as a barrier.
In more detailed experiments, the researchers tested the sealing properties of this polymer in stretchable electronic devices, including batteries and heat transfer systems. The results showed that the polymer again helped both devices perform excellently, allowing the battery to maintain high capacity after 500 cycles and improving the thermal conductivity of the heat transfer system.
Finally, the research team added a signal-transmission window to the polymer and demonstrated that it could also be used to transmit wireless signals. Overall, these experiments demonstrate the broad potential for applications of this flexible, waterproof material.
One potential drawback is the relatively high cost of EGaIn. However, the research team stated that while cost is not the primary focus of this study, there is scope for material optimization to reduce costs. One proposed approach is to use thinner EGaIn films.
Post time: Apr-20-2026