In brain-computer interface (BCI) and other neural interface systems, electrodes serve as the core interface sensor connecting electronic devices with biological neural systems—the very essence of the "interface." However, current implanted electrodes are predominantly "static," meaning they are fixed in place after implantation, limiting their ability to adapt or reposition. Over time, they often fail due to the body’s immune response, severely restricting the practical applications and future potential of BCI technologies. Recently, researchers from the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, have developed a groundbreaking solution: a flexible, stretchable, hair-thin neural fiber electrode called NeuroWorm. This innovation introduces a new paradigm in BCI—dynamic electrodes—breaking away from the long-standing limitations of static implants and opening up a new frontier in neural interface research and application. Traditional implanted electrodes cannot adjust their position after placement and lack responsiveness to their biological environment. To overcome this, the research team designed a sophisticated electrode structure using advanced coiling techniques, resulting in a fiber electrode just 196 micrometers in diameter with 60 independently distributed recording channels along its length. To enable movement, a tiny magnetic control unit was embedded at the tip of the fiber. By combining this with a high-precision magnetic control system and real-time imaging tracking, the electrode can autonomously navigate within the body, adjusting its direction and position on demand. The researchers named this mobile electrode NeuroWorm. In experiments with rabbits, NeuroWorm successfully "swam" through the brain, dynamically switching between different neural targets based on task requirements. The team also demonstrated long-term functionality in muscle tissue—NeuroWorm remained stable and continuously recorded electromyographic (EMG) signals in rats’ leg muscles for over 43 weeks. Notably, after 13 months of implantation, the average thickness of the fibrous tissue encapsulating NeuroWorm was less than 23 micrometers, and the rate of cell apoptosis around the implant was comparable to that of healthy tissue, indicating excellent long-term biocompatibility. This breakthrough paves the way for advanced applications in exoskeleton control, rehabilitation assistance, and human-machine collaboration in everyday environments. NeuroWorm marks the first time that passive, fixed implants have transitioned into intelligent, actively controllable, and biologically responsive systems. The research team plans to further explore dynamic flexible electrodes and "active" responsive electrode systems to accelerate the development of next-generation brain-computer interfaces. The findings were published in the journal Nature on September 17, with a detailed paper available that outlines the design, fabrication strategy, and demonstration of NeuroWorm’s dynamic monitoring capabilities in both brain and skeletal muscle tissues.