Sougata Hazra
Ph.D. Student in Mechanical Engineering, admitted Spring 2018
All Publications
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Techno-economic feasibility analysis of an extreme heat flux micro-cooler.
iScience
2023; 26 (1): 105812
Abstract
An estimated 70% of the electricity in the United States currently passes through power conversion electronics, and this percentage is projected to increase eventually to up to 100%. At a global scale, wide adoption of highly efficient power electronics technologies is thus anticipated to have a major impact on worldwide energy consumption. As described in this perspective, for power conversion, outstanding thermal management for semiconductor devices is one key to unlocking this potentially massive energy savings. Integrated microscale cooling has been positively identified for such thermal management of future high-heat-flux, i.e., 1kW/cm2, wide-bandgap (WBG) semiconductor devices. In this work, we connect this advanced cooling approach to the energy impact of using WBG devices and further present a techno-economic analysis to clarify the projected status of performance, manufacturing approaches, fabrication costs, and remaining barriers to the adoption of such cooling technology.
View details for DOI 10.1016/j.isci.2022.105812
View details for PubMedID 36624838
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Parametric design analysis of a multi-level 3D manifolded microchannel cooler via re duce d order numerical modeling
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
2022; 197
View details for DOI 10.1016/j.ijheatmasstransfer.2022.123356
View details for Web of Science ID 000859718300008
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A novel hardmask-to-substrate pattern transfer method for creating 3D, multi-level, hierarchical, high aspect-ratio structures for applications in microfluidics and cooling technologies.
Scientific reports
2022; 12 (1): 12180
Abstract
This letter solves a major hurdle that mars photolithography-based fabrication of micro-mesoscale structures in silicon. Conventional photolithography is usually performed on smooth, flat wafer surfaces to lay a 2D design and subsequently etch it to create single-level features. It is, however, unable to process non-flat surfaces or already etched wafers and create more than one level in the structure. In this study, we have described a novel cleanroom-based process flow that allows for easy creation of such multi-level, hierarchical 3D structures in a substrate. This is achieved by introducing an ultra-thin sacrificial silicon dioxide hardmask layer on the substrate which is first 3D patterned via multiple rounds of lithography. This 3D pattern is then scaled vertically by a factor of 200-300 and transferred to the substrate underneath via a single shot deep etching step. The proposed method is also easily characterizable-using features of different topographies and dimensions, the etch rates and selectivities were quantified; this characterization information was later used while fabricating specific target structures. Furthermore, this study comprehensively compares the novel pattern transfer technique to already existing methods of creating multi-level structures, like grayscale lithography and chip stacking. The proposed process was found to be cheaper, faster, and easier to standardize compared to other methods-this made the overall process more reliable and repeatable. We hope it will encourage more research into hybrid structures that hold the key to dramatic performance improvements in several micro-mesoscale devices.
View details for DOI 10.1038/s41598-022-16281-5
View details for PubMedID 35842450
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Thermal and Manufacturing Design Considerations for Silicon-Based Embedded Microchannel Three-Dimensional-Manifold Coolers (EMMC)-Part 3: Addressing Challenges in Laser Micromachining-Based Manufacturing of Three-Dimensional-Manifolded Microcooler Devices
ASME. 2020
View details for DOI 10.1115/1.4047847
View details for Web of Science ID 000576282500020
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Thermal and Manufacturing Design Considerations for Silicon-Based Embedded Microchannel-Three-Dimensional Manifold Coolers-Part 2: Parametric Study of EMMCs for High Heat Flux (similar to 1kW/cm(2)) Power Electronics Cooling
ASME. 2020
View details for DOI 10.1115/1.4047883
View details for Web of Science ID 000576282500019
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ADDRESSING THE CHALLENGES IN LASER MICRO-MACHINING AND BONDING OF SILICON MICROCHANNEL COLD-PLATE AND 3D-MANIFOLD FOR EMBEDDED COOLING APPLICATIONS: PERFECT DEBRIS REMOVAL
AMER SOC MECHANICAL ENGINEERS. 2020
View details for Web of Science ID 000518236000010
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Considerations and Challenges for Large Area Embedded Micro-channels with 3D Manifold in High Heat Flux Power Electronics Applications
IEEE. 2020: 77-82
View details for Web of Science ID 000701365300011
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Microfabrication Challenges for Silicon-based Large Area (> 500 mm(2)) 3D-manifolded Embedded Microcooler Devices for High Heat Flux Removal
IEEE. 2020: 83-90
View details for Web of Science ID 000701365300012