South Korea’s Pusan National University Develops μETF Technology for Advanced Neural Interfaces

Researchers at Pusan National University have developed a novel microelectrothermoforming (μETF) technique to create flexible 3D microelectrode arrays (MEAs) for neural interfaces. This one-step fabrication process enhances electrode-neuron proximity, lowering stimulation thresholds and improving neural recording precision, with potential applications in artificial retina devices, brain-computer interfaces (BCIs), and neuroprosthetics.

Conventional MEAs are flat and struggle to conform to curved neural tissues, limiting their effectiveness. The μETF technique, inspired by plastic thermoforming, allows the fabrication of intricate 3D electrode structures in a single step, eliminating complex, multi-step manufacturing processes. The research, led by Associate Professors Joonsoo Jeong and Kyungsik Eom, was published in npj Flexible Electronics on January 22, 2025.

“Our 3D structures bring electrodes closer to neurons, making neural stimulation more efficient and precise,” said Dr. Kyungsik Eom. A proof-of-concept study showed that 3D MEAs reduced stimulation thresholds by 1.7 times and improved spatial resolution by 2.2 times compared to flat electrodes.

The μETF method involves heating a thin liquid crystal polymer (LCP) sheet embedded with microelectrodes and pressing it onto a 3D-printed mold, forming precise wells, domes, walls, and triangular features. This innovation could revolutionize BCIs, helping restore movement in paralyzed patients by translating neural signals into physical actions.

Beyond neural interfaces, μETF could enhance wearable electronics, lab-on-a-chip systems, and organoid studies, offering new possibilities for medical and biomedical engineering applications. Researchers are now working on refining the technique for broader clinical use.