Mechanical Sensing and Control using Complex Fluids

Dr. Laurel Kroo

This seminar will discuss harnessing properties of complex fluids for sensing and control. These micro-structured fluids are the toolkit used by biological cells to construct organic “micro-robots”, enabling sophisticated and decentralized functionality such as precision temperature perception (Zhong, Kroo and Prakash, RS Interface 2023), multi-actuator coordination for locomotion (Bull, Kroo and Prakash, ArXiv 2021), or local stiffness control (Kroo, Bull and Prakash, Soft Matter 2023). But this toolkit of “complex fluids” is applicable to biomimicry and central across diverse chemical/ manufacturing industries, including food science, pharmaceuticals, and 3D printing. This talk will focus on the dynamics of a canonical complex fluid: a nonlinear viscoelastic fluid. I will discuss new methods to quantify two different non-linear bulk properties of these fluids: positive normal stress differences (in shear) and extensional thickening (in stretching fields).

   Dr. Laurel A. Kroo is a postdoctoral scholar in MIT's Non-Newtonian Fluids Lab, working with microstructured fluids such as polymer solutions, colloidal suspensions, and foams. Laurel received her Masters and PhD from Stanford University as an NSF Graduate Research Fellow (GRFP), and her Bachelors of Science from Olin College of Engineering. Dr. Kroo investigates the nonlinearities of complex fluids to construct non-biological adaptive materials. In addition to her more fundamental scientific work, Dr. Kroo has also been involved with several more applied projects focused on global equity/inclusion, such as the Foldscope Project (Prakash, Cybulski and Kroo, Patent US9810892B2) and a Covid-19 reusable-mask project which protected 30,000+ healthcare workers in 2020 (Kroo et al. PLOSone 2021). Dr. Kroo plans to launch a lab that combines societally-impactful research with deeply fundamental science. The Kroo Group will utilize the unique non-linearities of complex fluids to explore new solutions to global challenges like decarbonization, battery development and macromolecular drug synthesis. The theme of her lab will be constructing physiochemical machines controlled solely by mechanical / hydrodynamic feedback (such as via flow amplitude, flow type, confinement, and activity).  Dr. Kroo’s most recent recognitions include an awardee for the 2023 Berkeley MechE Rising Stars program, a 2023 Rowland Fellows finalist at Harvard, the 2022 Caltech Young Investigator Lectureship, and a 2023 invited ChemE department lecture at Rensselaer Polytechnic Institute. Dr. Kroo holds numerous patents/patent applications, and previously worked/interned extensively as an engineer in the industry, including at NASA, Apple, and several start-ups.

https://columbiauniversity.zoom.us/j/96392321461?pwd=b0NjdmxQTWUxOGN2cXBWQVJRZ0ppdz09

Meeting ID: 963 9232 1461

Security: 676451