EAGER: Two-Dimensional Material-Based Epidermal Active Sensors for Brain Monitoring.

EAGER：用于大脑监测的基于二维材料的表皮主动传感器。

• 批准号: 1541684
• 负责人: Nanshu Lu
• 金额: $ 16万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1541684&HistoricalAwards=false
• 关键词: EAGER; Two; Dimensional; Material; Based

Electroencephalographic (EEG) measures subtle voltage fluctuations along the scalp resulting from ionic current flows within the neurons of the brain. EEG is widely used as a low cost, portable, and noninvasive means to capture not only cognitive and memory performance, but also brain disorders like epilepsy and stroke. Conventional EEG recording is obtained by placing individual thick and stiff electrodes on the scalp with conductive gel after skin abrasion which enhances electrode-skin contact. For many decades, EEG technology has suffered from limitations such as low spatial resolution, poor signal-to-noise ratio without proper signal amplification, time consuming and obstructive electrode connections, and short measurement time as gel dries out. Such limitations are partially due to the incompatibility between the soft, curvilinear, and deformable human skin and the hard, planar, and rigid electrodes and electronics. The ultrathin, high electronic performance, and transparency of atomically thick two-dimensional materials offer clear mechanical, electronic, and optical advantages over silicon in the neuroelectronics. This research proposes to explore the idea of replacing conventional rigid EEG electrodes by tattoo-like ultrathin, ultrasoft, dry electrodes and signal amplifiers fabricated from two-dimensional materials. Preliminary results indicate this idea is feasible and further research will prove the feasibility and future prospects for tattoo-like, long lasting, and high performance neuroelectronics to benefit society. In addition, the graduate student and post-doctoral researchers working on this research effort will gain advanced scientific and engineering skills needed to be technical leaders in industry, academia or government post-graduate careers. Moreover, undergraduate students from diverse backgrounds will be recruited to participate in the research effort to promote advanced science and engineering careers.The objective of this proposal is to carry out a feasibility study that two-dimensional materials such as graphene and atomically thin molybdenum disulfide can be applied as the electrode and amplifier materials for noninvasive, long-term, high fidelity Electroencephalographic sensing. The major technical barrier towards two-dimensional materials based epidermal active EEG sensor lies in the device design, heterogeneous fabrication, and reliable bio-integration with the final goal of enhanced EEG sensing. An innovative active electrode architecture is proposed in which graphene is employed as both the sensing and gate electrodes, and molybdenum disulfide integrated with ultrathin polymer dielectrics and graphene source/drain as the on-site signal amplifier. Two research thrusts are proposed to accomplish the feasibility study: i) fabricating and validating graphene based passive epidermal EEG electrodes, and ii) integrating molybdenum disulfide vertically on top of the graphene electrode with ultrathin polymer dielectrics and graphene source/drain as a transistor amplifier for active EEG recording. The expected outcome is an affirmative decision on the feasibility of an integrated neuroelectronics that can be conformally laminated on human skin without conductive gel but still able to record long term, high fidelity EEG with orders of magnitude signal amplification. For the targeted gain of several hundreds the active electrode minimizes both the extrinsic noise and allows substantial reduction of the electrode arrays.

脑电图（EEG）测量大脑神经元内离子电流流动产生的沿头皮的微妙电压波动。脑电图作为一种低成本、便携式、无创的手段被广泛使用，不仅可以捕获认知和记忆表现，还可以捕获癫痫和中风等脑部疾病。传统的脑电图记录是通过在皮肤磨损后用导电凝胶将单个厚而硬的电极放置在头皮上来获得的，这增强了电极与皮肤的接触。几十年来，脑电图技术一直受到诸如空间分辨率低、信噪比差、没有适当的信号放大、耗时且有阻碍性的电极连接以及凝胶干燥时测量时间短等限制。这种限制部分是由于柔软、曲线和可变形的人体皮肤与坚硬、平面和刚性的电极和电子设备之间的不兼容性造成的。原子厚二维材料的超薄、高电子性能和透明度在神经电子学领域比硅具有明显的机械、电子和光学优势。这项研究提出探索用二维材料制成的类似纹身的超薄、超软、干电极和信号放大器取代传统的刚性脑电图电极的想法。初步结果表明这一想法是可行的，进一步的研究将证明类纹身、持久、高性能神经电子学造福社会的可行性和未来前景。此外，从事这项研究工作的研究生和博士后研究人员将获得成为工业界、学术界或政府研究生职业的技术领导者所需的先进科学和工程技能。此外，还将招募来自不同背景的本科生参与研究工作，以促进先进的科学和工程事业。该提案的目的是开展可行性研究，研究石墨烯和原子薄二硫化钼等二维材料可用作无创、长期、高保真脑电图传感的电极和放大器材料。基于二维材料的表皮主动脑电图传感器的主要技术障碍在于设备设计、异构制造和可靠的生物集成，最终目标是增强脑电图传感。提出了一种创新的有源电极架构，其中石墨烯用作传感电极和栅电极，二硫化钼与超薄聚合物电介质和石墨烯源极/漏极集成作为现场信号放大器。提出了两个研究重点来完成可行性研究：i）制造和验证基于石墨烯的被动表皮脑电图电极，以及ii）将二硫化钼垂直集成在石墨烯电极顶部与超薄聚合物电介质和石墨烯源极/漏极作为用于主动脑电图记录的晶体管放大器。预期的结果是对集成神经电子学的可行性做出肯定的决定，该神经电子学可以在不使用导电凝胶的情况下保形地层压在人体皮肤上，但仍然能够记录长期、高保真脑电图，并具有多个数量级的信号放大。对于数百的目标增益，有源电极最大限度地减少了外在噪声，并允许大幅减少电极阵列。