Nonlinear Dynamics of Nanopore Current Oscillations

纳米孔电流振荡的非线性动力学

• 批准号: 0825661
• 负责人: Craig Martens
• 金额: --
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0825661&HistoricalAwards=false
• 关键词: Nonlinear; Dynamics; Nanopore; Current; Oscillations

Oscillatory behavior has been observed for almost all electrochemical systems in a certain range of external parameters. Electrochemical oscillators based on membranes are studied as model systems of oscillatory biological processes, and propagation of action potential in neurons. The intellectual merit of the research supported by the Dynamical Systems Program is to prepare and model a new type of membrane electrochemical oscillators based on single tapered-cone shaped nanopores. In strongly soluble salt solutions e.g. potassium chloride, conical nanopores act as molecular current rectifiers. When traces of sparingly soluble species, such as CaHPO4 are present, the system undergoes an intriguing transformation from DC current flow to quasiperiodic current oscillations when a critical membrane voltage is reached. External parameters will be identified that allow for tuning the frequency of current oscillations in the range between fractions of Hz up to several tens of Hz. The ion current oscillations will also be stable for several hours. The experimental data will be subjected to nonlinear dynamics analysis in order to distinguish random noise from deterministic chaos in these nanosystems, and for the latter case characteristics such as attractor dimension and Lyapunov exponents will be extracted from the recordings. The nonlinear dynamics analysis will be performed in parallel to the phenomenological modeling of ion current oscillations using coupled chemical kinetics differential equations. Universal character of this dissipative system far from equilibrium will be investigated as well.Success of the project will lead to preparation and modeling of a new type of electrochemical oscillators, which could be applied as a working element of an ionic circuit, artificial cells, and sensory systems. The research will also result in nonlinear dynamics characterization of nanopore based electrochemical oscillators, and in better understanding of systems that function far from equilibrium in physiological, water based conditions. Education program of this project is focused on organizing hands-on activities for middle and high school students in nanotechnology at UC Irvine. The outreach activities will be done in collaboration with the UCI School Partnership in Research and Information Technology (SPIRIT) program. Interdisciplinary training in nonlinear dynamics tools, electrochemistry, surface studies, and biophysics will be offered to undergraduate and gradate students.

在一定的外部参数范围内，几乎所有电化学系统都观察到了振荡行为。基于膜的电化学振荡器作为振荡生物过程和神经元动作电位传播的模型系统进行研究。动力系统计划支持的研究的智力价值是制备和建模基于单锥形纳米孔的新型膜电化学振荡器。在强溶性盐溶液中，例如氯化钾，圆锥形纳米孔充当分子电流整流器。当存在微量难溶物质（例如 CaHPO4）时，当达到临界膜电压时，系统会经历从直流电流到准周期电流振荡的有趣转变。将确定外部参数，以允许在几分之一赫兹到几十赫兹之间的范围内调整电流振荡的频率。离子电流振荡也将稳定几个小时。实验数据将接受非线性动力学分析，以便区分这些纳米系统中的随机噪声和确定性混沌，对于后者，将从记录中提取吸引子维数和李亚普诺夫指数等特征。非线性动力学分析将与使用耦合化学动力学微分方程的离子电流振荡唯象建模并行进行。还将研究这种远离平衡的耗散系统的普遍特征。该项目的成功将导致新型电化学振荡器的制备和建模，该振荡器可用作离子电路、人造细胞和传感系统的工作元件。该研究还将对基于纳米孔的电化学振荡器进行非线性动力学表征，并更好地理解在生理、水基条件下远离平衡的系统。该项目的教育计划重点是为加州大学欧文分校的中学生和高中生组织纳米技术的实践活动。外展活动将与 UCI 学校研究和信息技术合作伙伴关系 (SPIRIT) 项目合作完成。将为本科生和研究生提供非线性动力学工具、电化学、表面研究和生物物理学的跨学科培训。