Research Projects

Non-woven quasi-two-dimensional networks comprising interconnected fibers are ubiquitous in biological and bioengineered systems. These networks are found in extracellular matrix, connective tissues, spider webs, scaffolds for tissue growth and regeneration, drug delivery systems, and in consumer products like filtration systems, energy devices, protective vests, and paper. The global market value of non-woven fabrics was between $40‒$50 billion in 2021, with an annual production of approximately 13 million tons. The industry has maintained a consistent growth rate of 7.5% annually worldwide. This presents a significant opportunity for our country to capitalize on this growth. Furthermore, given the widespread usage of nanofiber networks in various applications, it is crucial to understand the structure-property correlation of these networks and their composites, leading to successful design of non-woven networks with desired strength, ductility, and failure characteristics. It is also particularly relevant when these nanofiber networks act as the load-bearing member, such as in hydrogels. One of the key challenges in studying the mechanics of non-woven nanofiber networks is their complex hierarchical structure which leads to non-affine deformation. To date, the mechanical properties of these networks and their composites and how they respond to external forces are not well understood. Thus, this proposal aims to investigate the deformation mechanics of non-woven nanofiber networks with bonded and non-bonded contact interfaces between nanofibers and their composites. The proposed research will investigate the relationship between the network structure, individual fiber properties, and inter-fiber interactions and the deformation behavior of nanofiber networks at the micrometer length scales. In-situ tensile tests under an optical microscope will help in understanding the mechanical response of quasi-2D networks both individually and when embedded within a polymer matrix. The principal investigator’s (PI’s) prior work involving fabricating nanofiber networks using electrospinning and measuring adhesion and friction between individual polymer nanofibers will be valuable in carrying out the proposed work. Computational cohesive-zone modeling (using finite element methods) along with statistical analysis will also be used to simulate and predict the behavior of the networks under various loading conditions. The findings of this research will provide useful insights into the design and optimization of nanofiber networks and their composites. The proposed research will also contribute to the development of new class of non-continuum materials with unique mechanical properties. Overall, this research with combined experimental and numerical modeling will provide a better understanding of the mechanics of deformation behavior in nanofiber networks and their composites, which has significant implications for a wide range of applications.