Researchers at Washington State University and Lawrence Berkeley National Laboratory have discovered a way to make ions move more than 10x faster in mixed organic ion-electronic conductors. The method combines the advantages of ion signaling, used by biological systems like the human body, with electron signaling, used by computers.
The research speeds up ion movement by using molecules that attract and concentrate ions into a separate nanochannel, creating a type of tiny “ion superhighway.” These advances are expected to have significant implications for improved battery charging, biosensing, soft robotics, and neuromorphic computing. Their results are published in Advanced Materials under the title Local Chemical Enhancement and Gating of Organic Coordinated Ionic-Electronic Transport.
These conductors allow the simultaneous movement of both ions and electrons, which is critical for battery charging and energy storage. They also power technologies that combine biological and electrical mechanisms, such as neuromorphic computing, which attempts to mimic thought patterns in the human brain and nervous system.
During their investigations, the team observed that ions moved relatively slowly within the conductor. Due to their coordinated movement, the slow ion flow also slowed the electrical current. The ions traveling through the conductor faced a matrix, described as a “rat’s nest” of pipelines for electrons, which impeded their speed.
To solve this issue, the researchers created a straight, nanometer-sized channel specifically for ions. Inspired by how living cells, including those in the human body, use ion channels to move compounds in and out of cells, the team employed molecules that either attract or repel water. By using water-loving (hydrophilic) molecules that attracted electrolytes, ions moved through the channel more than 10x faster than through water alone. This movement set a new world record for ion speed in any material. Conversely, when they lined the channel with water-repelling molecules, ions were forced to travel through the slower “rat’s nest.”
The team found that chemical reactions could flip the molecules’ attractiveness to electrolytes, effectively opening or closing the ion superhighway, much like biological systems control access through cell walls. Using this mechanism, they created a sensor that could quickly detect a chemical reaction near the channel. When a reaction occurred, it would open or close the ion superhighway, generating an electrical pulse that a computer could read.
Original Story: https://news.wsu.edu/press-release/2024/11/18/new-ion-speed-record-holds-potential-for-faster-battery-charging-biosensing/
