MechE Seminar Series: Andrea Pickel

Speaker: Andrea Pickel

Title: Taking Luminescence Thermometry to Extremes for Device, Energy, and Catalysis Applications

Abstract: From next-generation electronics to lithium-ion batteries to emerging catalytic processes, broad swaths of modern technology combine a need for micro- to nanoscale thermal metrology with challenging operating conditions. However, existing thermometry techniques often fall short of providing the requisite spatial resolution and operando capabilities. This talk will present three examples of pushing the boundaries of luminescence thermometry to address such challenges. First, a super-resolution nanothermometry technique based on stimulated emission depletion (STED) imaging of highly doped upconverting nanoparticles (UCNPs) will be introduced, which enables far-field optical thermometry with spatial resolution below the diffraction limit. The results showcase the ability of STED nanothermometry to reveal a temperature gradient across a Joule-heated microstructure that is undetectable with diffraction-limited thermometry. Second, the application of operando UCNP thermometry to dual-functional materials (DFMs), which combine endothermic CO2 desorption with an exothermic reaction, will be discussed. By incorporating UCNPs into a model DFM, temperature rises ~10-100 K above the catalyst bed set temperature are recorded. Finally, operando internal battery thermometry via UCNPs incorporated into commercial lithium-based coin cells will be highlighted. Under elevated discharge currents, temperature differences of several degrees between internal components and the battery exterior are observed.

About the Speaker: Andrea Pickel is an Assistant Professor in the Walker Department of Mechanical Engineering at the University of Texas at Austin. She is the recipient of an American Chemical Society Petroleum Research Fund Doctoral New Investigator Award, an NSF CAREER Award, and the G. Graydon Curtis ’58 and Jane W. Curtis Award for Non-Tenured Faculty Teaching, and she was named a Scialog Fellow for Automating Chemical Laboratories. Andrea received her Ph.D. in Mechanical Engineering from the University of California, Berkeley, where she was supported by an NSF Graduate Research Fellowship and a UC Berkeley Chancellor’s Fellowship. She received her B.S. in Mechanical Engineering with University and College Honors from Carnegie Mellon University. From 2019-2025, she was an Assistant Professor at the University of Rochester.