Mechanically Stable Ultrathin Layered Graphene Nanocomposites Alleviate Residual Interfacial Stresses: Implications for Nanoelectromechanical Systems.
Mechanically Stable Ultrathin Layered Graphene Nanocomposites Alleviate Residual Interfacial Stresses: Implications for Nanoelectromechanical Systems.
复制标题
机械稳定的超薄石墨烯纳米复合材料减轻了残余界面应力：对纳米机电系统的影响。
DOI：
10.1021/acsanm.2c03955
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发表时间：
2022-12-23
影响因子：
5.9
通讯作者：
Coveney, Peter, V
中科院分区：
文献类型：
--
作者：
Vassaux, Maxime;Muller, Werner A.;Suter, James L.;Vijayaraghavan, Aravind;Coveney, Peter, V
关键词：
由聚合物电介质沉积在二维纳米材料（如石墨烯）上制成的先进纳米机电系统在压力和触摸传感器、谐振传感器和电容式微机械超声换能器（CMUTs）中越来越受欢迎。然而，层状纳米复合材料的耐久性和精度取决于聚合物和石墨烯层之间界面的机械稳定性。在这里，我们使用分子动力学计算机模拟来研究在与工作状态相关的大量高频（MHz）弯曲循环期间，石墨烯片和聚苯乙烯- c热塑性聚合物层之间的界面。我们发现，在使用条件下，重要的界面滑动几乎立即发生，导致膜膨胀超过2%，这是一种有害的机制，需要反复校准以保持CMUTs的精度。这种不可逆机制是由纳米复合材料双分子层中残余内应力的松弛引起的，导致聚合物中出现自平衡张力，石墨烯中出现压缩。它是由于沉积-聚合工艺条件而产生的。我们的研究结果表明，需要特别注意克服最初的扩张。选择合适的化学材料，包括低静电相互作用，也将是它们作为耐用和可靠的设备成功应用的关键。
Advanced nanoelectromechanical systems made from polymer dielectrics deposited onto 2D-nanomaterials such as graphene are increasingly popular as pressure and touch sensors, resonant sensors, and capacitive micromachined ultrasound transducers (CMUTs). However, durability and accuracy of layered nanocomposites depend on the mechanical stability of the interface between polymer and graphene layers. Here we used molecular dynamics computer simulations to investigate the interface between a sheet of graphene and a layer of parylene-C thermoplastic polymer during large numbers of high-frequency (MHz) cycles of bending relevant to the operating regime. We find that important interfacial sliding occurs almost immediately in usage conditions, resulting in more than 2% expansion of the membrane, a detrimental mechanism which requires repeated calibration to maintain CMUTs accuracy. This irreversible mechanism is caused by relaxation of residual internal stresses in the nanocomposite bilayer, leading to the emergence of self-equilibrated tension in the polymer and compression in the graphene. It arises as a result of deposition–polymerization processing conditions. Our findings demonstrate the need for particular care to be exercised in overcoming initial expansion. The selection of appropriate materials chemistry including low electrostatic interactions will also be key to their successful application as durable and reliable devices.
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用于柔性电子应用的具有石墨烯势垒层的低功率聚对二甲苯忆阻器
影响因子：
6.2
作者：
Chen, Qingyu;Lin, Min;Huang, Ru
通讯作者：
Huang, Ru
DOI：
10.1098/rsta.2020.0082
发表时间：
2021-05-17
期刊：
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
影响因子：
--
作者：
Wan S;Sinclair RC;Coveney PV
通讯作者：
Coveney PV
影响因子：
3.3
作者：
Guryel, S.;Walker, M.;Wilson, M. R.
通讯作者：
Wilson, M. R.
影响因子：
4
作者：
Sabri, S. S.;Levesque, P. L.;Szkopek, T.
通讯作者：
Szkopek, T.
影响因子：
4.6
作者：
Suter JL;Coveney PV
通讯作者：
Coveney PV