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Caltech Young Investigators Lecture

Thursday, May 5, 2022
11:00am to 12:00pm
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Online Event
Adaptive and Sensory Machines: From Active Foam to Swimming Rheometers
Laurel Kroo, P.h.D. candidate, Stanford University,

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In this talk, we will discuss passive adaptation and sensing in fully-synthetic engineered systems, with two specific examples. First, in the context of studying the self-assembly of programmable soft matter, we discuss the response of 2D air-liquid foam to cyclical inflation and deflation of an embedded active bubble. Experimental and numerical results suggest that such volume oscillations can be used to train foam to achieve local structural properties, communicate long-range mechanical signals through the chiral motion of vertex trajectories, and may be used to actively probe properties of the surrounding network structure.

In the next example, we will discuss how an untethered robot is capable of self-propulsion at low Reynolds number, but only when submerged in a non-Newtonian, viscoelastic fluid. This robot consists of two counter-rotating rotationally-symmetric objects, and propels itself in the direction of the larger "head" object. By controlling the relative rotation rate of this device while recording motility, the robot acts as rheological sensor of the surrounding fluid, with remarkable sensitivity.

Fundamentally, these examples demonstrate how adaptive and sensory machines can be used in engineering to enable exceptional redundancy and robustness in real-world environments.


Laurel A. Kroo is a senior P.h.D. candidate in Mechanical Engineering at Stanford University, under the mentorship of Professor Manu Prakash. Her interests center on the intersection between robotics and soft condensed matter physics. Specifically, her primary research is focused on topics related to self-organization under confinement, distributed control in soft materials, and actuation/sensing in non-newtonian fluids. Her former professional affiliations include employment at Apple, NASA Ames Research Center and a number of San Francisco Bay-Area hardware start-ups. She is a Hertz Fellowship finalist and a recipient of the National Science Foundation's Graduate Research Fellowship.

This talk is part of the Caltech Young Investigators Lecture Series, sponsored by the Division of Engineering and Applied Science.

For more information, please contact Stacie Takase by email at [email protected].