Proposal Number: CTS-050004 Principal Investigator: Mohseni, Kamran Affiliation: University of Colorado-Boulder Proposal Title: SGER: Electrowetting Actuation of Droplets for Cooling of Integrated Circuits
This award is for a Small Grant for Exploratory Research awarded by the Thermal Transport and Thermal Processing Program of the Division of Chemical and Transport Systems. Heat is an unavoidable byproduct of normal operation of an electronic device. Reduction in circuit delay and therefore an increase in speed are often achieved by higher circuit packaging density accompanied by increased power dissipation per circuit. As a result of more demand for increased packaging density and performance, the required heat flux removal is increasing at a challenging rate. To this end, this Small Grant for Exploratory Research (SGER) is focused on electrical modulation of discrete droplets for actuation and pumping of liquid droplets, in particular metals/alloys, for active thermal management of compact micro systems and heat removal from the hot spots on any solid surface. Preliminary calculations suggest significant heat removal capability by using this technique.
Intellectual Merit: This effort is aimed at providing quantitative data in support of the proposed technique. The proposed technique is based on two observations: (i) By using metals/alloys that are liquid at room temperature (instead of e.g. air cooling) heat transfer rate of a cooling system can be enhanced significantly, (ii) Electrocapillary is an efficient, low power consumption, and low voltage actuation technique for pumping liquids at micro-scales. Feasibility analysis for such a system will be conducted by focusing on two separate aspects of the project. First, modeling of both electrowetting on dielectric (for conductive liquids) and dielectrophoresis (for dielectric liquids) will be conducted to find droplet velocity and heat transfer rate for a given actuation voltage. In order to validate these models, experiments will be conducted where the heat transfer coefficients and droplet velocities are directly measured for various actuation parameters.
Broader Impacts: It is expected that this project will create innovative advances in a new class of thermal management techniques for compact micro systems. Existing disciplinary courses at CU Boulder will be enriched with results from this work, expanding student multidisciplinary exposure to thermofluidics, micro fabrication, and numerical simulation. Advances in thermal management of compact micro systems and micro fluidics are anticipated based on the research proposed in this investigation. These will be disseminated widely at national meetings and through journal publications.
