SHF: Medium: Back to the Future with Printed, Flexible Electronics Design in a Post-CMOS Era when Transistor Counts Matter Again

随着晶体管技术的显著进步，电路现在可以在各种嵌入式衬底上构建，例如柔性，可拉伸，保形和抗冲击以及大面积格式。这些技术将极大地扩展微电子的应用空间，包括辐射检测、健康诊断、药物输送、分布式传感、信息显示、食品安全、识别标签、库存跟踪、机器人和人机接口。该项目的目的是为随机比特流计算范式提供概念验证，端到端验证，并将其应用于一项有前途的新技术，即印刷柔性电子产品。与目前的CMOS技术相比，柔性电子系统在给定表面上可以构建的器件数量受到严重限制，因此，使用非常少量的晶体管进行计算变得至关重要。该项目的目标是使用概率来表示数字，并采用一种新颖的电路设计范例，以显着减少柔性电子产品中使用的晶体管数量。伴随该项目的教育计划将在课堂上推广概率计算，训练学生通过应用多种技术来设计端到端系统。柔性电子和机器人技术将利用现有的机构外展项目，如Lotus Stokes少数民族参与联盟和Northstar STEM联盟，指导K-12学生，并促进少数民族和女学生的工程教育。本提案旨在将随机比特流计算范例应用于印刷电子产品的设计挑战。在这种范例中，电路对随机比特流进行计算，其信号值由在流中获得“1”与“0”的概率编码。由于比特流表示是均匀的，所有比特的权重相等，因此以这种方式设计的电路对软错误的容忍度很高。更重要的是，复杂的操作可以用非常简单的逻辑来执行。例如，乘法运算可以用一个与门来执行。一般来说，该方法可以显著减少晶体管数量。测试平台将由一个低电压、柔性压力传感器阵列和嵌入式随机计算元件组成，作为机器人脚的电子皮肤。总的来说，该项目将开发以下任务作为测试平台的一部分：综合方法；架构和应用；输入/输出接口;并开发新的低温、增材制造印刷电子产品的方法，这将减少设备占地面积，从而同时增加每个区域的设备数量并增加带宽。

With remarkable progress in transistor technology, circuits can now be built in all manner of embedded substrates, e.g., flexible, stretchable, conformal and impact-resistant and large-area formats. Such technologies will greatly expand the application space for microelectronics, including radiation detection, health diagnostics, drug-delivery, distributed sensing, information display, food security, identification tagging, inventory tracking, robotics, and human-machine interfacing. The aim of this project is to provide a proof-of-concept, end-to-end validation of the paradigm of stochastic bit stream computation, applying it to a promising new technology, namely, printed flexible electronics. Compared to the current CMOS technology, flexible electronic systems have severe limitations on the number of devices that can be built on a given surface, and thus, it becomes critical to perform computations with a very small number of transistors. The goal of this project is to use probabilities to represent numbers and employ a novel circuit design paradigm to significantly reduce the number of transistors used in flexible electronics. The education plan accompanying the project will promote probabilistic computing in the classroom, training students to design end-to-end systems by applying multiple technologies. Flexible electronics and robotics will be leveraged to mentor K-12 students and promote engineering education amongst minority and female students by taking advantage of existing institutional outreach programs such as Lotus Stokes Alliance for Minority Participation and Northstar STEM Alliance.This proposal seeks to apply the paradigm of stochastic bit stream computation to the design challenge of printed electronics. In this paradigm, circuits compute on random bit streams with signal values encoded by the probability of obtaining a "one" versus a "zero" in the streams. Because the bit stream representation is uniform, with all bits weighted equally, circuits designed this way are highly tolerant of soft errors. More importantly, complex operations can be performed with very simple logic. For instance, multiplication can be performed with a single AND gate. In general, the methodology provides significant reduction in transistor counts. The test platform will consist of a low voltage, flexible pressure sensor array with embedded stochastic computational elements to act as an electronic skin for a robot's foot. Broadly, the project will develop the following tasks as part of the test platform: synthesis methodologies; architectures and applications; input/output interfacing; and developing new low temperature, additive manufacturing approaches to printed electronics that will decrease device footprints, thereby simultaneously increasing the device count per area and increasing bandwidth.