Sponsors: ARPA-E, NSF POETS Center, Ford, Intel, Google, Bosch
Collaborators: NREL, UC Merced, Toyota, U of Arkansas, U of Illinois Urbana Champaign, Ford, Bosch


The development of high performance heat exchangers has enjoyed a long tradition of research at Stanford University dating back to the early work by Kays and London (Compact Heat Exchangers, 1958) and the progress by Tuckerman and Pease on the first microchannel heat sink (Electron Device Letters, 1980).

We are rapidly extending this tradition with breakthrough approaches to heat sink design based on microfabrication, innovative materials, engineered surfaces, and 3D hierarchical manifolding.  This work engages multiple students focussing on boiling fundamentals, surface chemistry, phase separation in variable-permeability porous media, and micro/nanofabrication.  There are extensive simulation and experimental components to these projects, as well as active cooperations with simulation groups and companies seeking applications of these novel heat sinks.

The Nanoheat Lab and collaborators have been at the forefront of microfluidic cooling research for nearly two decades, including early work on MEMS-based metrology for temperature and phase distributions in two-phase microchannel convection. Additional progress includes visualization methods for phase and pressure distributions in microchannel convection, as well as characterization of microchannel condensation flow.

We also provided the first demonstration and characterization of a novel vapor-escape microfluidic heat exchanger, which uses a gas-permeable membrane to reduce the pressure drop required to achieve thermal resistance targets. We are exploring the use of nanostructured materials, including silicon nanopillar arrays, as advanced wicking structures for compact heat pipes and vapor chambers.  This approach was integrated with 3D manifolding, etched diamond microchannels (with Raytheon), and copper inverse opals as part of the DARPA ICECOOL Program to achieve a record-setting heat sink for power electronics cooling.

In 2001 and 2002, this group authored series of patents that were the foundation for a startup company, Cooligy, which developed novel and sold microfluidic heat sinks for Apple desktop computers in 2005 and 2006. Cooligy was acquired by Emerson in 2005.  Today, we are collaborating with leading vehicle and  power electronics companies on designs that excel in this critical application space.

DARPA Heat Sink
We built a world-record heat sink with DARPA support using diamond microchannels, 3D manifolding, and copper inverse opals for improved liquid transport.