###### Abstract
In research, non-invasive EEG electrodes are key in neuroscience, brain-computer interfaces, and cognitive assessment, where a precise and stable signal is essential for studying cognition and brain mapping [31]. In the study by [PERSON] et al. [32], dry and wet electrodes were compared in EEG with 16 healthy subjects and 16 neurological patients. The results showed that although dry electrodes had slightly more artifacts and higher impedance, EEG signals, including evoked potentials, were comparable between both systems. Most participants preferred the dry electrodes for their ease of use and portability. These results suggest that dry electrodes are a viable option for both clinical and home applications with less susceptibility to electromagnetic interference. In summary, the quality of EEG signals is crucial for the diagnosis and treatment of various neurological conditions, as well as for research in neuroscience, where different types of brainwaves provide valuable information about the state and function of the brain. Improving the design and fit of EEG helmets is essential to ensure the accuracy of these signals and optimize both therapies and scientific studies. The work presented in [33] describes the design and development of an affordable portable EEG headset based on the OpenBCI Ultracortex Mark IV system. The primary goal is to improve the accessibility and usability of BCI technologies by providing a cost-effective and efficient solution for rehabilitation and remote control applications. The headset was validated through experiments with 20 participants and compared to commercial devices in terms of cost, signal quality, setup time, and comfort. The results showed that the self-designed device offers competitive performance, reduced setup time, and 82% precision in specific tasks, such as slide control through voluntary blinking. The authors conclude that this device presents a viable alternative for users with clinical and personal needs with potential for future design improvements and expanded applications. The article presented by [34] focuses on the design of wearable EEG devices specialized for passive brain-computer interface (PBCI) applications. It addresses the challenge of optimizing electrode configurations to enhance the accuracy of detecting emotional and attentional states. Using EEG data sets related to emotion recognition and attention monitoring, the authors developed electrode setups specific to emotion, specific to attention, and general purpose, evaluating them in multiple configurations with two, four, six, and eight electrodes. Their results showed that optimized configurations outperformed conventional commercial devices, suggesting that specialized electrode placement can significantly improve the performance of PBCI systems. This research highlights the potential of customized EEG devices for various real-world applications, such as neurofeedback, consumer behavior analysis, and driver vigilance detection. Unlike studies reviewed in the literature, this work presents an innovative EEG headband that allows precise sensor position adjustment and customization of the overall dimensions of the device, ensuring better fit and performance. The contributions of our work are as follows:  
* Modular and adaptable design: the headband is compatible with various skull sizes, implementing an ergonomically optimized design, obtaining an improved arrangement of the electrodes that allows obtaining a more precise and focused signal in the region of interest that maintains optimal contact regardless of head shape. * Optimized placement: The system positions all electronic components at the back of the head, minimizing external disturbances during EEG recordings. * Use of advanced flexible materials: the headband incorporates polymer-conductor materials, ensuring precise sensor positioning, flexibility. These features make this headband a highly versatile tool suitable for clinical and personal use, significantly improving existing devices.