Paper Number
GV1                         My Program 

Session
Gallery of Rheology - Videos

Title
Pinching cytoskeleton composites

Presentation Date and Time
October 22, 2025 (Wednesday) 6:30

Track / Room
Gallery of Rheology Session: Videos / Sweeney Ballroom E+F

Authors (Click on name to view author profile)

1. Razzaghi, Aysan (University of San Diego, Physics and Biophysics)
2. Valentine, Megan T. (university of California Santa Barbara, Mechanical Engineering)
3. McGorty, Ryan J. (University of San Diego, Physics and Biophysics)
4. Robertson-Anderson, Rae M. (University of San Diego, Physics and Biophysics)

Author and Affiliation Lines (in printed abstract book)
Aysan Razzaghi¹, Megan T. Valentine², Ryan J. McGorty¹ and Rae M. Robertson-Anderson^1
1Physics and Biophysics, University of San Diego, San Diego, CA 92108; ²Mechanical Engineering, university of California Santa Barbara, Santa Barbara, CA 93106

Speaker / Presenter 
Razzaghi, Aysan

Keywords
experimental methods; biorheology; microscopy; networks; non-Newtonian fluids

Text of Abstract
Active cytoskeletal composites (ACCs) — in vitro reconstitution of actin filaments, microtubules, and motor proteins — are structurally and mechanically heterogeneous. In this video, we use holographic optical tweezers to trap multiple micron-sized beads within an ACC and periodically move them to locally “pinch” the network. This multiplexed shearing allows us to simultaneously probe locations with different connectivity and stiffness, mapping spatiotemporal stress propagates through this complex medium. The multiplexed shear-induced deformation reveals time evolving correlations, and space-dependent responses.