Macro Scale

Drs. William King and Nenad Miljkovic with collaborators at the University of Illinois at Urbana-Champaign have developed a millimeter-scale high-contrast thermal switch that can be used for cooling in power electronics and a variety of other electrical and thermal power systems. This liquid-metal based, electrically-controlled thermal switch controls heat transfer of thermally sensitive systems with hotspots smaller than 1 mm and as large as 1 cm and beyond. This technology has a high switching ratio (>10), high switching speed (>1Hz), and it utilizes liquid metal alloys with reduced toxicity, high thermal conductivity and surface tension. Liquid-based thermal switches are the most promising solutions for thermal management at room temperature. They allow to reduce the contact thermal resistance, enhance the operational speed and reduce heat losses. This new device will enable development of thermal circuit in the electrical and thermal power systems on a practical level.

Dr. Nam from the University of IL has developed flexible metal conductor that incorporates an interfacial layer of graphene. Adding a layer of graphene to the metal conductor enhances the failure strain of the electrode by 300% or more. This invention enhances the mechanical robustness and prevents abrupt electrical performance failure at large strains. Additionally, this invention allows for predictive failure for electrical devices based on measured electrical resistance. The invention has potential applications in flexible electronics. The invention also has potential application in predicative failure for electrical cables.

The emergence of datacenters as single computer entities has made latency a critical consideration in designing datacenter networks. PCIe interconnect is known to be a latency bottleneck in communication networks as its overhead can contribute to up to 90% of the overall communication latency. PCIe is a standard motherboard interface, sending a packet over a conventional NIC requiring several PCIe and memory channel transactions. This data movement in the network software stacks consumes thousands of processor cycles, which ultimately prevent ultra-low latency networking.

Researchers eliminate NIC-PCIe transactions and instead use the local memory channels between the memory and NIC, resulting in reduced latency and improved data center computer performance (figure 1). This finding is the basis for NetDIMM, which is a method for integrating a network interface chip with the memory module of a computer.

Figure 1: State of the art network interface architectures vs. NetDIMM

On average, NetDIMM improves per packet latency by 49.9% compared with a baseline network deploying PCIe NICs (figure 2). The NetDIMM architecture is located in the memory module and does not require any change to the processor architecture or memory subsystem.

Figure 2: One-way network latency breakdown for packets of various sizes when using a PCIe NIC (left), an integrated NIC (middle), and NetDIMM (left). X-axis is not drawn to scale.

Most recently, NetDIMM was presented at the 52nd IEEE/ACM International Symposium on Microarchitecture in Columbus, Ohio. The conference publication can be accessed here.