Qianying Wu is a PhD candidate in the Mechanical Engineering Department at Stanford.
Growing up in a hot and humid climate in south China, Qianying developed her particular interest in thermal management. In the Nanoheat lab and advised by Prof. Ken Goodson, she is currently working on the design and fabrication of microporous wicking structures for capillary-driven two-phase heat and mass transfer, the simulation and integration of such engineered structures in novel high heat flux cooling devices, and exploring ways to utilize these technologies for positive energy and sustainability impact.
Qianying received her B.S in Engineering with top honors from Tsinghua University, where she was awarded the Xia An Shi Prize and National Scholarship, and her B. Econ from the School of Economics and Management at Tsinghua, where she was supported by a Fu Lai Chun Scholarship.
Honors & Awards
TomKat Center Graduate Fellow for Translational Research, TomKat Center for Sustainable Energy (2021)
Graduated with Honors, Tsinghua University (2018)
Education & Certifications
B.Eng, Tsinghua University, Building Science (2018)
B.Econ, Tsinghua University, Economics (2018)
Summer Intern, Nokia Bell Labs (6/7/2021 - 8/13/2021)
Murray Hill, NJ
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.
2022; 12 (1): 12180
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
Partitioning of airborne PAEs on indoor impermeable surfaces: A microscopic view of the sorption process.
Journal of hazardous materials
2021; 424 (Pt A): 127326
Organic films were widely found on indoor impermeable surfaces exposed to gaseous organic compounds, but few studies have addressed the film growth details on different indoor substrates. In this study, we observed the topography evolution of phthalic acid ester (PAE) organic films on three impermeable substrates: polished glass (G-P), mirror-polished stainless steel (SS-M) and drawn stainless steel (SS-D). PAE organic films were preferentially formed upon the flat surface with sparse inherent nano-peaks of substrate G-P and in valleys of substrate SS-M and SS-D. Surface uniformity of substrates and viscosity of PAE molecules were inferred as critical parameters determining the surface average adhesion forces. We obtained the partition coefficients of DEP, DnBP, BBP and DEHP on substrate G-P, SS-M and SS-D by fitting the initial monolayer adsorption process. Organic films continuously grew instead of reaching adsorption equilibrium after long-term PAE exposure, indicating that multilayer adsorption may occur. The organic film growth rates in saturated gas-phase PAE concentrations were quantified as about one-tenth of the results in previous studies where substrates were simultaneously exposed to multiple pollutants. To sum up, the results outline PAE adsorption details on impermeable materials and provide a reference for better estimation on PAE exposure assessment.
View details for DOI 10.1016/j.jhazmat.2021.127326
View details for PubMedID 34597933