Investigations into Droplet-Based Microelectrofluidic Technology for Hot Spot Cooling and Thermal Management in Integrated Circuits

特征尺寸的减小和封装密度的增加使得热问题在集成电路（IC）设计中变得极其重要。ic中不均匀的热图和热点会导致物理压力和性能下降，还会降低可靠性。本研究项目的重点是嵌入式冷却方法和热管理的集成电路设计流程。该项目的目标是开发基于液滴微流体的芯片冷却新技术，并将该技术与集成电路（IC）设计流程联系起来。它利用了最近由美国国防部高级研究计划局资助的杜克大学的一项研究成果，该研究成果导致了一种新的基于电润湿的液滴传输技术。它是基于在电压控制下微升和纳米级液滴的高速电润湿传输。冷却液可以在2d电极阵列的定时电压控制下以用户定义的模式输送，而不需要外部泵和阀门。此外，液体流量随着温度的升高而固有地增加。因此，芯片上的局部热区域将增加局部冷却，而不需要外部传感器。该项目还专注于流体通道结构的设计，流体通道将为对流冷却输送液滴。虽然液滴路径是在设计时静态分配的，但液滴传输速率是在运行时动态确定的。正在开发模拟和剖面工具，以确定现场作业期间不同通道和不同时间的液滴传输速率。正在研究的其他主题包括液滴路由协议和液滴布局的优化技术。这个项目将导致一个独立的，自我调节的，低功耗（微瓦）芯片冷却技术。从这项工作中获得的见解有望为新一代用于计算和通信的嵌入式系统以及高端高速计算平台铺平道路。电源管理和热问题被广泛视为集成电路发展的主要障碍；该项目有望帮助克服这些障碍。该项目也是两个不同研究团体之间的重要桥梁。它为微流体领域的研究人员提供了一个主要的应用驱动程序，以继续研究纳米升和皮升尺度的液滴流动方法。另一方面，它使IC设计人员能够利用先进的液滴流技术进行芯片冷却。

Decreasing feature sizes and increasing package densities are making thermal issues extremely important in integrated circuit (IC) design. Uneven thermal maps and hot spots in ICs cause physical stress and performance degradation, and they also reduce reliability. This research project is focused on embedded cooling methods and an IC design flow forthermal management.The goal of the project is to develop new techniques for chip cooling based on droplet microfluidics, and to relate this technology to the integrated circuit (IC) design flow. It leverages a recent DARPA-funded research effort at Duke University that led to a novelelectrowetting-based droplet transport technology. It is based on high-speed electrowetting transport of discrete microliter- and nanoliter-sized droplets under voltage control. Cooling liquids can be transported, in user-defined patterns, under clocked-voltage control over a 2D-array of electrodes without the need for external pumps and valves.In addition, liquid flow is inherently increased with increasing temperature. Thus, local hot areas on a chip will have increased cooling applied locally without the need for external sensors.The project is also focused on the design of the architecture for fluidic pathways, which will transport droplets for convective cooling. While the droplet paths are statically allocated during design time, the rate of droplet transport is dynamically determined during run-time. Simulation and profiling tools are being developed to determine the rate of droplet transport on different channels and at different times during field operation. Additional topics being investigated include protocols for droplet routing and optimization techniques for droplet layout. This project will result in a self-contained, self-regulated, and low power ( a microwatt) chip cooling technique. The insights gained from this work are expected to pave the way for a new generation of embedded systems for computing and communications, as well as high-end, high-speed computation platforms. Power management and thermal problems are being widely seen as major roadblocks in the evolution of ICs; this project is expected to help overcome these roadblocks. This project also serves as an important bridge between two diverse research communities. It provides researchers from the microfluidics area with a major application driver for continued research into droplet-flow methods at the nanoliter and picoliter scales. On the other hand, it enables IC designers to leverage advances in droplet-flow technology for chip cooling.