Stanford scientists have unlocked new insights into the structure of organic mixed ionic-electronic conductors (OMIECs), positioning these materials as key players in the future of semiconductors. By using advanced cryo-electron microscopy techniques, the team has revealed how OMIECs, when soaked in liquid electrolyte, can maintain their electrochemical properties while swelling—making them resilient, adaptable materials for next-generation electronics.
OMIECs are flexible, soft polymers with exceptional electrochemical characteristics, making them appropriate for applications in batteries, sensors, and especially semiconductors. But the real mystery has always been how these materials keep working under stress—and now, thanks to new research, we’re finally getting some answers.
“When OMIEC polymers are immersed in a liquid electrolyte, they swell, like an accordion, yet maintain electronic functionality,” said Professor Alberto Salleo from Stanford University, a senior researcher of the study which was published in September 2024 at Nature Materials. The polymer chains in OMIECs can stretch and curve without breaking, preserving a continuous path for electron movement—a crucial property for any material used in electronics.
Stanford’s breakthrough was made possible through the use of cryo-electron microscopy (Cryo 4D-STEM), a technique that allowed researchers to visualize OMIECs at an atomic level, even as they expanded by up to 300%. Such swelling would typically destroy the functionality of most electronic materials, but OMIECs seem to thrive under these conditions, continuing to allow for efficient electron and ion transport.
“The polymers exhibit impressive resilience to the physical changes and ion insertion compared to other materials we’ve studied, and that’s a desirable trait for future electronics,” explained postdoctoral scholar Yael Tsarfati, the first author of the paper.
What makes OMIECs particularly attractive for semiconductor development is their ability to maintain performance while undergoing mechanical changes. These materials form a gel-like structure that allows for stretching and bending without losing their conductive properties, meaning they could be crucial in developing more durable and flexible semiconductors.
“Learning how a material works at a structural level is key to designing ever-better materials,” Tsarfati stated.
As electronic devices continue to shrink and bend, materials like OMIECs, which can perform well under pressure, become increasingly valuable. This opens up new directions for designing better materials, and the team’s findings could soon have implications far beyond just semiconductors. OMIECs are bound to find applications across various cutting-edge technologies, such as artificial intelligence.
AI technologies are expanding into wearable devices, making these materials’ adaptability even more valuable. Wearable AI, from health monitors to robotics, benefits from OMIECs’ ability to function in physically dynamic environments, offering high performance in devices that need to bend and stretch with use.
The resilience and adaptability of OMIECs provide a foundation for advancing semiconductor technology, bringing researchers one step closer to developing more durable, efficient, and flexible electronic devices for the future.