Mapping molecular-level dynamics to mesoscale mechanics in composite DNA-based biomaterials
Abstract
Most naturally occurring biomaterials, such as cytoskeleton and mucus, are heterogeneous biopolymer compositesthat display captivating and useful scale-dependent viscoelastic properties that are completely controlled by polymer topology, stiffness, size and concentration. Thus, biopolymer composites are powerful platforms for developing dynamic, multifunctional materials. However, understanding the underlying macromolecular dynamics and stress propagations that lead to the unique macroscale mechanics is critical to precisely tuning composites to have desiredmaterial properties. The proposed research will elucidate the mechanics of novel biologically-inspired biopolymer composites from the molecular-level to mesoscales and from steady-states to nonlinear perturbations; unequivocally mapping intrinsic molecular properties to composite mechanics, microscale dynamics to macroscale stress response, and molecular strain to stress propagation. The PI will introduce a new technique, Scalable Active-Passive Molecular Rheology (SAPMR), that combines optical tweezers microrheology, single-molecule conformational-tracking, and mesoscale fluorescence image analysis to directly connect stresses induced in biopolymer composites to corresponding molecular deformations and network rearrangement with unprecedented temporal, spatial and molecular resolution. Specifically, the PI will optically drive microsphere transducers through biopolymer composites while simultaneously tracking embedded DNA sensor molecules and measuring the force the composite exerts to resist the microscale strain. Tracking sensor dynamics over 5 orders of magnitude, from nanoscales to near-macroscales, will precisely quantify induced molecular conformations and mobility, and directly map molecular strain propagation through the composite. Post-strain sensor and transducerdynamics will resolve relaxation spectra spanning 6 orders of magnitude, from milliseconds to hours, linking conformational relaxation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2017
- Source ID
- FA95501710249
Entities
People
- Rae Robertson-Anderson
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of San Diego