Equivalent optically transparent circuits: an optimization-driven methodology for the design of optically transparent sensors and antennas

触摸传感器是智能手机、平板电脑和可穿戴健康监测仪等个人电子设备用户界面不可或缺的组件。这些传感器是普通的电路，其通常的铜线被光学透明（几乎不可见）的导体所取代，如氧化铟锡（ITO）。与铜相比，光学透明导体具有更高的损耗，使用光学透明导体使得这些电路的设计成为一项具有挑战性的任务。电路设计人员基本上是在试错的基础上应对这一挑战的，他们使用电路模型和电磁仿真的组合来推导出以性能换取光学透明度的拓扑结构。随着个人和可穿戴电子设备市场的竞争一如既往，新的触摸传感器预计将支持低延迟的多任务手势的高速率感测。这些更严格的规范测试目前的设计工具的限制，激励进一步研究的最佳性能界限的透明电路和拓扑结构，满足这些界限在给定的制造constrain.The本建议解决了这一迫切需要通过引入等效光学透明电路（EOTC）的概念。这些二端口和四端口电路的综合优化，旨在最大限度地减少他们的性能和他们的铜基同行的性能之间的差异。利用电磁结构的凸优化和不确定性量化技术的进步，该项目旨在为标准（ITO）和新兴（银纳米线，石墨烯）材料制成的透明电路导出一个构建模块的“字典”，就像一维/二维微带线用于铜基材料一样。除了触摸传感器之外，还将探索EOTC概念在透明天线和多功能触摸输入/天线表面设计中的应用。

Touch sensors are indispensable components of the user interface of personal electronic devices such as smartphones, tablet computers and wearable health monitors. These sensors are ordinary circuits, whose usual copper wires are replaced by optically transparent (practically invisible) conductors such as Indium Tin Oxide (ITO). The use of optically transparent conductors, which suffer from higher losses compared to copper, makes the design of these circuits a challenging task. Circuit designers have by and large dealt with this challenge on a trial-and-error basis, using a combination of circuit models and electromagnetic simulations to derive topologies that trade performance for optical transparency. With the market for personal and wearable electronic devices as competitive as ever, new touch sensors are expected to support high-rate sensing of multi-tasking gestures with low latency. These stricter specifications test the limits of current design tools, motivating further research on the optimal performance bounds of transparent circuits and the topologies that meet those bounds under given fabrication constraints.The present proposal addresses this urgent need by introducing the concept of equivalent optically transparent circuits (EOTCs). These two and four-port circuits are synthesized by optimization aimed at minimizing the difference between their performance and the performance of their copper-based counterparts. Leveraging advances in convex optimization of electromagnetic structures and uncertainty quantification techniques, this project is aimed at deriving a "dictionary" of building blocks for transparent circuits made with standard (ITO) and emerging (silver nanowires, graphene) materials, just as one/two-dimensional microstrip lines are for copper-based ones. In addition to touch sensors, applications of the EOTC concept to the design of transparent antennas and multi-functional touch-input/antenna surfaces will be explored.