Murphy Brendan B, Mulcahey Patrick J, Driscoll Nicolette, Richardson Andrew G, Robbins Gregory T, Apollo Nicholas V, Maleski Kathleen, Lucas Timothy H, Gogotsi Yury, Dillingham Timothy, Vitale Flavia
Department of Bioengineering, 210 S. 33rd Street, 240 Skirkanich Hall, University of Pennsylvania, Philadelphia, PA, United States 19104.
Department of Chemistry, 37th & O Streets NW, Georgetown University, Washington, DC, United States 20057.
Adv Mater Technol. 2020 Aug;5(8). doi: 10.1002/admt.202000325. Epub 2020 Jun 21.
Wearable sensors for surface electromyography (EMG) are composed of single- to few-channel large-area contacts, which exhibit high interfacial impedance and require conductive gels or adhesives to record high-fidelity signals. These devices are also limited in their ability to record activation across large muscle groups due to poor spatial coverage. To address these challenges, we have developed a novel high-density EMG array based on titanium carbide (TiCT) MXene encapsulated in parylene-C. TiCT is a two-dimensional nanomaterial with excellent electrical, electrochemical, and mechanical properties, which forms colloidally stable aqueous dispersions, enabling safe, scalable solutions-processing. Leveraging the excellent combination of metallic conductivity, high pseudocapacitance, and ease of processability of TiCT MXene, we demonstrate the fabrication of gel-free, high-density EMG arrays which are ~8 μm thick, feature 16 recording channels, and are highly skin-conformable. The impedance of TiCT electrodes in contact with human skin is 100-1000x lower than the impedance of commercially-available electrodes which require conductive gels to be effective. Furthermore, our arrays can record high-fidelity, low-noise EMG, and can resolve muscle activation with improved spatiotemporal resolution and sensitivity compared to conventional gelled electrodes. Overall, our results establish TiCT-based bioelectronic interfaces as a powerful platform technology for high-resolution, non-invasive wearable sensing technologies.
用于表面肌电图（EMG）的可穿戴传感器由单通道至多通道的大面积触点组成，这些触点具有高界面阻抗，需要使用导电凝胶或粘合剂来记录高保真信号。由于空间覆盖性差，这些设备在记录大肌肉群的激活情况方面也受到限制。为应对这些挑战，我们开发了一种基于聚对二甲苯-C封装的碳化钛（TiCT）MXene的新型高密度EMG阵列。TiCT是一种具有优异电学、电化学和机械性能的二维纳米材料，它能形成胶体稳定的水分散体，实现安全、可扩展的溶液加工。利用TiCT MXene的金属导电性、高赝电容和易加工性的出色组合，我们展示了无凝胶、高密度EMG阵列的制造，该阵列厚度约为8μm，具有16个记录通道，且与皮肤高度贴合。与需要导电凝胶才能有效工作的市售电极相比，与人体皮肤接触的TiCT电极的阻抗低100 - 1000倍。此外，我们的阵列能够记录高保真、低噪声的EMG，并且与传统的凝胶电极相比，能够以更高的时空分辨率和灵敏度分辨肌肉激活情况。总体而言，我们的结果确立了基于TiCT的生物电子接口作为高分辨率、非侵入性可穿戴传感技术的强大平台技术。
