This postdoc is funded through the MURI "Cellular Mechanics and Process Principles of 3D Secretion for Ultralight Multifunctional Materials in Butterfly Wing Scales." The goal of this project is to decipher the biological, physical, and chemical mechanisms that enable living cells to secrete complex hierarchical structures in functional biological materials, specifically butterfly wing scales.
The University of Vermont is seeking a Lecturer or Senior Lecturer in the area of Dynamical Systems and other broad areas starting on August 24, 2026. This is a great opportunity to teach at a state flagship university and Land Grant Institution whose vision is to be among the nation’s premier research universities with a comprehensive commitment to a liberal arts education, environment, health, and public service.
Noe Reyes Rivas
Applied Mathematics, Brown University
Time: 11:00 am - 12:00 pm (EST), Feb. 05, Thursday
Zoom Meeting ID: 824 6447 8256
Passcode: 003801
Abstract
In this paper we formulate a geometric theory of elasticity and anelasticity for bodies containing material surfaces with their own elastic energies and distributed surface eigenstrains. Bulk elasticity is written in the language of Riemannian geometry, and the framework is extended to material surfaces by using the differential geometry of hypersurfaces in Riemannian manifolds.
Two-dimensional (2D) lattice materials with well-designed microstructures exhibit extraordinary properties such as zero and negative Poisson’s effects, and play a crucial role in industrial fields. However, inevitable defects from manufacturing, storage, transportation, and service may compromise their microstructures and functionalities. Therefore, it is important but still unclear: which microstructures and associated properties are most or least sensitive to defects.
Film-substrate systems are prevalent in various industries, and manipulation of their adhesion strength is essential to guarantee their desired functionalities. Inspired by the heterogeneous characteristic of geckos’ spatulae, heterogeneous adhesion devices are proposed for enhanced directional adhesion, but experimental measurements of their adhesion strength are significantly lower than the theoretical predictions. This discrepancy is likely due to the cohesive zone, a factor that was usually overlooked in previous theoretical models.
While the surface asperities of mineral platelets are widely believed to play important roles in stiffening, strengthening, and toughening nacre, their effects have not been thoroughly investigated. Here, a computationally efficient bar-spring model is adopted to simulate, as platelets with multiple interfacial asperities slide over each other, the tensile force versus elongation behaviors as well as the effective mechanical properties such as modulus, strength, and work-to-fracture in nacre or nacre-like composites.
Fast stress wave attenuation in composites is highly desired in many industry fields. Biological composites such as those in the beak of woodpeckers provide great inspiration for us to develop their synthetic counterparts with similar mechanical functions.
Interface plays a critical role in the mechanical performance of composites. Lack of a suitable interface design has long been a bottleneck impeding the full exploitation of the mechanical strengths of many superior reinforcement phases such as the high-performance carbon fibers and carbon nanotubes.
Nacre is well known for its high strength and toughness owing to its ingenious “brick-and-mortar” microstructure. However, its impact resistance has not been studied as well as its static properties, even though protecting fragile organs from external dynamic loadings is one of its most important functions.
