Microstructure integrated continuum model and numerical scheme for the design and characterization of 2-D microstructured materials

点击翻译按钮获取中文摘要

The applicant's research team is currently on the forefront of the design and analysis of biocompatible composite materials which have drawn an increasing attention in recent years for their various applications in the fields of biomechanics and nanomechanics. Due to the lack of rigorous prediction models describing highly non-linear and coupled responses, the fabrication and characterization of such materials are mainly based on "trial and error" which significantly compromise the efficiency and precision. The long-term objective of the proposed research is to establish a propound analytical platform for the design and characterization of 2-D microstructured materials by developing innovative continuum models and robust numerical techniques. As such, the proposed research program will address the following two major branches of problems: 1. Pseudo-elastic and continuum damage models for the mechanics of the hyperelastic materials reinforced with fibrous fibers. Aging-related health issues have become a significant source of social and economic burden. The uses of health monitoring systems and assistive devices can be an effective means of promoting health and social independence of impacted groups. However, there exist formidable technical challenges including the developments of biocompatible composite films sustaining various in-vivo and/or in-vitro environments. The proposed research intends to develop comprehensive continuum models that can facilitate the design and fabrication of hyperelastic composite films. This includes the refinement of a series of continuum-based models to account for pseudo-elasticity and strain stiffening/softening responses. The kinematics and mesh orientations of reinforcing fibrous fibers will also be formulated by using their position and director fields. We begin with the case of unidirectional fiber composites and subsequently extend the results to the more general scenarios of multi-directional fibers and initially non-orthogonal fiber meshes. 2. Morphological transitions of lipid bilayer membranes induced by surface dilation, protein diffusion and intra-membrane lipid viscosity. In the proposed research, we aim to develop continuum-based models and molecular dynamics schemes for the analysis of lipid membrane morphology. The microstructure characteristics of lipid bilayer membranes will be modeled via a dimension reduction procedure applied to 3-D liquid crystal theory from which the non-standard effects of lipid distension and tilt can be accommodated. A variant of the obtained model will also be considered to incorporate the generalized capillarity of lipid membranes pertaining to higher gradient effects such as surface dilation, protein diffusion and intramembrane viscous flow. Outcomes from the proposed research can be directly applied to the design of biosensors and effective drug delivery mechanisms and will eventually enhance our understanding of a wide range of essential cellular functions.