Biosciences and Bioengineering Graduate Program, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates.
Department of Chemical and Biological Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates.
Sensors (Basel). 2024 May 21;24(11):3260. doi: 10.3390/s24113260.
The advancement of flexible electrodes triggered research on wearables and health monitoring applications. Metal-based bioelectrodes encounter low mechanical strength and skin discomfort at the electrode-skin interface. Thus, recent research has focused on the development of flexible surface electrodes with low electrochemical resistance and high conductivity. This study investigated the development of a novel, flexible, surface electrode based on a MXene/polydimethylsiloxane (PDMS)/glycerol composite. MXenes offer the benefit of featuring highly conductive transition metals with metallic properties, including a group of carbides, nitrides, and carbonitrides, while PDMS exhibits inherent biostability, flexibility, and biocompatibility. Among the various MXene-based electrode compositions prepared in this work, those composed of 15% and 20% MXene content were further evaluated for their potential in electrophysiological sensing applications. The samples underwent a range of characterization techniques, including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), as well as mechanical and bio-signal sensing from the skin. The experimental findings indicated that the compositions demonstrated favorable bulk impedances of 280 and 111 Ω, along with conductivities of 0.462 and 1.533 mS/cm, respectively. Additionally, they displayed promising electrochemical stability, featuring charge storage densities of 0.665 mC/cm and 1.99 mC/cm, respectively. By conducting mechanical tests, Young's moduli were determined to be 2.61 MPa and 2.18 MPa, respectively. The composite samples exhibited elongation of 139% and 144%, respectively. Thus, MXene-based bioelectrodes show promising potential for flexible and wearable electronics and bio-signal sensing applications.
柔性电极的发展推动了可穿戴设备和健康监测应用的研究。基于金属的生物电极在电极-皮肤界面处存在机械强度低和皮肤不适的问题。因此，最近的研究集中在开发具有低电化学电阻和高导电性的柔性表面电极。本研究探讨了一种基于 MXene/聚二甲基硅氧烷（PDMS）/甘油复合材料的新型柔性表面电极的开发。MXenes 具有高度导电性的过渡金属特性，包括一组碳化物、氮化物和碳氮化物，而 PDMS 则具有固有生物稳定性、柔韧性和生物相容性。在本工作中制备的各种基于 MXene 的电极组合物中，进一步评估了含有 15%和 20% MXene 含量的组合物在电生理传感应用中的潜力。这些样品经历了一系列的特征化技术，包括电化学阻抗谱（EIS）、循环伏安法（CV）以及来自皮肤的机械和生物信号传感。实验结果表明，这些组合物的体阻抗分别为 280 和 111 Ω，电导率分别为 0.462 和 1.533 mS/cm。此外，它们表现出良好的电化学稳定性，电荷存储密度分别为 0.665 mC/cm 和 1.99 mC/cm。通过进行机械测试，确定杨氏模量分别为 2.61 MPa 和 2.18 MPa。复合材料样品的伸长率分别为 139%和 144%。因此，基于 MXene 的生物电极在柔性和可穿戴电子设备以及生物信号传感应用方面具有广阔的应用前景。
