Precision Organic Electrochemical Transistors for Single-Cell Electrophysiology

时间分辨的有机电化学晶体管的原位计量，以支持动态器件模型的发展摘要非技术：有机电化学晶体管（OECTs）是一类新兴的生物相容性有机半导体器件，工作在非常低的电压和非常高的放大。 这种特性的组合使它们对于外部和植入式生物电子学具有吸引力，例如测量肌肉或神经元的电活动。 然而，由于对晶体管内部功能的不完全理解以及限制集成和可重复性的基本制造方法，目前的进展受到限制。 晶体管的内部动力学将与一些显微镜技术应用于操作晶体管，以告知一个理论器件模型的组件进行研究。 该模型将指导基于这些晶体管的新生物医学设备的创建，包括细胞动作电位的测量。技术：OECTs通过注入离子来取代掺杂剂聚离子，将聚合物通道可逆地转变为绝缘体，从而调节聚合物半导体的电导率。 本研究将阐明光刻制造的OECTs的时空动力学，基于导电聚合物聚（3，4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）。 所提出的技术包括实时，电致变色显微镜，以阐明在开关过程中的原位掺杂动力学，扫描开尔文探针显微镜，以测量更精细的尺度上的聚合物掺杂的空间分布，和原子力显微镜，以揭示聚合物的形态和溶胀，是至关重要的了解生理界面。这些研究将阐明离子传输和掺杂，电流和机械性能的工作设备的主动通道中的相互作用，从而更好地理解的结构-功能关系和验证的第一个完整的瞬态模型的OECT功能。 这种理解将指导改进制造方法的研究，包括UV光刻和表面活性剂，这些方法已被证明可以提高其他有机电子器件的性能和可重复性。 可重复的可编程制造将使器件集成和精确测量超越目前的能力。这些优化的传感器的性能将通过与神经样和骨骼肌细胞的整合来证明，这些细胞将被生物打印到OECT阵列和多电极阵列的栅极上进行比较。 这将在当地一家生物技术公司和两名CU细胞生物学合作者的协助下进行。 一个低噪声，多路复用的电接口的OECT阵列将被设计和建造的本科和推广计划的一部分。

Time-resolved in-situ metrology of organic electrochemical transistors to support the development of a dynamic device modelAbstract Nontechnical: Organic electrochemical transistors (OECTs) are an emerging class of biocompatible organic semiconductor device that operate at very low voltages and with very high amplification. This combination of properties makes them attractive for external and implanted bioelectronics such as measuring electrical activity of muscles or neurons. However, progress is currently limited by incomplete understanding of the internal functioning of the transistors and also rudimentary fabrication methods that restrict integration and repeatability. The internal dynamics of the transistors will be studied with a number of microscopy techniques applied to operating transistors to inform the assembly of a theoretical device model. This model will guide the creation of new biomedical devices based on these transistors including the measurement of cellular action potentials.Technical: OECTs modulate the conductivity of a polymer semiconductor by injecting ions that replace dopant polyions, reversibly transforming the polymer channel into an insulator. This study will elucidate the spatio-temporal dynamics of lithographically-fabricated OECTs, based on the conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). The proposed techniques include real-time, electrochromic microscopy to elucidate the in situ doping dynamics during switching, scanning Kelvin probe microscopy to measure the spatial distribution of polymer doping on even finer scales, and AFM to reveal polymer morphology and swelling that are critical to understanding the physiological interface. These studies will elucidate the interplay of ion transport and doping, current flow, and mechanical properties in the active channel of working devices, leading to a better understanding of the structure-function relationship and validation of the first complete transient model of OECT function. This understanding will guide the study of improved fabrication methods including UV photolithography and surfactants that have been shown to improve performance and repeatability of other organic electronic devices. Repeatable photolithographic fabrication will enable device integration and precision measurements beyond current capability. Performance of these optimized sensors will be demonstrated by integration with nerve-like and skeletal myocyte cells, which will be bio-printed onto the gates of OECT arrays and a multi-electrode array for comparison. This will be performed with the assistance of a local bio-tech firm and two CU cell biology collaborators. A low-noise, multiplexed electrical interface to the OECT array will be designed and built as part of the undergraduate and outreach program.