Microchannel Heat Sinks For Cooling High Heat Flux Electronic Devices―analysis With Single And Two Phase Flows

Microchannel heat sinks constitute an innovative cooling technology for the efficient dissipation of the large amounts of heat from the very small and constrained areas of the high heat flux microelectronic chips and circuits. Penyerap haba saluran mikro menjadikan sebuah teknologi penyejukan berinovatif bagi lesapan berkesan jumlah haba yang besar daripada kawasan yang amat kecil dan terhad bagi cip dan litar elektronik mikro fluks haba yang tinggi

Microchannel Heat Sinks For Cooling High Heat Flux Electronic Devices-Analysis With Single And Two Phase Flows [TK7872.H4 P896 2006 f rb].

Penyerap haba saluran mikro menjadikan sebuah teknologi penyejukan berinovatif bagi lesapan berkesan jumlah haba yang besar daripada kawasan yang amat kecil dan terhad bagi cip dan litar elektronik mikro fluks haba yang tinggi. Microchannel heat sinks constitute an innovative cooling technology for the efficient dissipation of the large amounts of heat from the very small and constrained areas of the high heat flux microelectronic chips and circuits

3D-ICE: a Compact Thermal Model for Early-Stage Design of Liquid-Cooled ICs

Liquid-cooling using microchannel heat sinks etched on silicon dies is seen as a promising solution to the rising heat fluxes in two-dimensional and stacked three-dimensional integrated circuits. Development of such devices requires accurate and fast thermal simulators suitable for early-stage design. To this end, we present 3D-ICE, a compact transient thermal model (CTTM), for liquid-cooled ICs. 3D-ICE was first advanced by incorporating the 4-resistor model based CTTM (4RM-based CTTM). It was enhanced to speed up simulations and to include complex heat sink geometries such as pin fins using the new 2 resistor model (2RM-based CTTM). In this paper, we extend the 3D-ICE model to include liquid-cooled ICs with multi-port cavities, i.e., cavities with more than one inlet and one outlet ports, and non-straight microchannels. Simulation studies using a realistic 3D multiprocessor system-on-chip (MPSoC) with a 4-port microchannel cavity highlight the impact of using 4-port cavity on temperature and also demonstrate the superior performance of 2RM-based CTTM compared to 4RM-based CTTM. We also present an extensive review of existing literature and the derivation of the 3D-ICE model, creating a comprehensive study of liquid-cooled ICs and their thermal simulation from the perspective of computer systems design. Finally, the accuracy of 3D-ICE has been evaluated against measurements from a real liquid-cooled 3D IC, which is the first such validation of a simulator of this genre. Results show strong agreement (average error<10%), demonstrating that 3D-ICE is an effective tool for early-stage thermal-aware design of liquid-cooled 2D/3D ICs

Nonreciprocity Applications in Acoustics and Microfluidic Systems

Breaking reciprocity in linear acoustic systems and designing a novel actuator for the nonreciprocal valveless pumps are studied in this dissertation. The first part was started by deriving the acoustic governing equations in a moving wave propagation medium. It was shown thatthe Coriolis acceleration term appears ina cross-product term with the wave vector. It means the main reason for breaking reciprocity in the circular fluid flow is the Coriolis acceleration term. Finally, the governing equations were solved numerically by COMSOL Multiphysics software. Moreover, Green`s second identity was used as a complimentary method to prove breaking reciprocityin such a system with moving medium. It is concluded that the non-reciprocity is magnified by increasing the angular velocity of the fluid system. The second part of this thesis is about achieving non-reciprocity utilizing the arrangement of a nozzle and diffuser as the inlet and outlet ports. This part’s goal is to design a novel flexible actuator design for a valveless pump. The actuation mechanism which is novel in its own term, uses liquid metal called galinstan, a non-magnetic but electrically conducting alloy. In the designed device, an alternating current (AC) is applied onto a microchannel filled with galinstan. This device is placed between two permanent magnets with opposing poles. Due to the Lorentz force law, there will be radial in-plane forces on the polymeric flexible substrate. These in-plane forces radially contract and expand the circular diaphragm to provide an upward and downward out of plane bending moment, which causes an oscillatory reciprocating movement similar to a piezoelectric actuator`s movement. Compared to the traditional piezo electric materials such as Lead Zirconate Titanate (PZT), this actuator has numerous advantages such as being flexible, having the ability to be scaled down, being formed as an integrated structure, and being fabricated by a considerably simple process. The prototype of the pump could be fabricated easily with Platinum Silicone rubber and some low-cost 3D printed elements. Although the prototype has been fabricated in a relatively large size, it is considered as a proper conceptual model representing the performance of the pump

Gas Flows in Microsystems

International audienc

Design of a Regulated Micromachined Air-Sniffer Using Thermal Transpiration Effect for E-Nose Applications

Microfluidics artificial olfaction systems are used for plant disease diagnosis in the agricultural field. In an electronic nose, the sniffer draws the air towards an array of gas sensors that detect volatile organic compounds corresponding to diseased plants. The currently available electronic noses involve a mechanical pump of moving parts prone to friction losses, limiting large-scale application. In this work, a microchannel that works on thermal transpiration principle to control the airflow inside it is proposed and designed. It has the potential to be employed as a sniffer component for electronic noses, designed using microelectromechanical systems. COMSOL Multiphysics simulation software is used to identify the design parameters of a three-dimensional microchannel and determine the airflow velocity resulting from the applied temperature using the Navier-Stokes and Energy equation. The heat transfer and fluid flow have been modelled for two different channel geometries (i.e., rectangular, and cylindrical) and two materials (i.e., pyrex and silicon). The proposed microchannel geometries are optimised to obtain the Knudsen number in the range of 0.00