The COSMOS lab’s research focus is on developing a framework to discover, design and develop broad classes of advanced materials and structures for a number of mechanical and aerospace systems – specifically soft and collaborative robotic structures, wearable technology, high temperature aerospace structures and inspection technologies.
To this end, we are especially interested in leveraging the interplay of materials and geometry to obtain unprecedented combinations of mechanical properties. This design principle is at the heart of rapidly expanding frontier of metamaterials. A significant focus of our group lies in observing nature and organisms, specifically revealing the fundamentals of its successful strategies and translating them into engineering design.
Developing new materials have driven much of engineering enterprise. There are two ways to advance the frontier – innovating on (1) matter itself (new materials) or (2) space (topology/architecture). By combining matter with space (architecture) a truly new frontier of materials development emerges. Such architected solids have traditionally proven to be difficult to manufacture due to intricate spatial geometries. However, rapid advances in additive manufacturing (AM) are making these materials increasingly viable. Still, predicting their properties and behavior is extremely challenging. Purely empirical or experiment driven enterprise is futile due to intractable complexity. Anticipating this issue, our team develops a program of integrated observational, multiscale/multiphysics modeling and experimental platform. The modeling tools are based on the rigorous principles of continuum mechanics and continuum thermodynamics. The computational tools developed for specific problems are based on nonlinear finite element (FE) methods, boundary element methods (BEM), numerical linear algebra and high performance computing. Experimental investigation is carried out using material testing and 3D digital image correlations (3D-DIC).
We are always looking for highly motivated, creative and mathematically strong students to pursue research in our group. If you are interested in undergraduate or graduate research opportunities, drop an email to the lab director. Postdoc positions, when available will be posted separately.
Fishes are an ancient life form, appearing early during the Cambrian explosion of life forms about 500 million years ago Although the first fishes probably did not possess scales, they appeared soon and eventually made their way forward to reptiles such as snakes and alligators, and even in some mammals. Natural scales are lightweight, stiff and highly multifunctional. Several critical properties including protection, locomotion, camouflaging, thermal regulation have been attributed to scales.
From a mechanical standpoint, their lightweight, stiffness and damage tolerance is of great interest for designing lightweight structures for aerospace applications and agile soft mechanical systems.
Scales have been used to make primarily two types of biomimetic structures. In the first architecture, they appear in the form of composite layers with fully embedded imbricated stiff inclusions into a thick soft substrate. The second architecture includes a soft substrate covered with exposed overlapping scales on its surface, an exoskeletal design. The exoskeletal design is of great significance due to a nonlinear interplay of scale sliding and substrate deformation.
Our lab has carried out pioneering work in this area understanding the mechanics of these systems and use the principles learnt in design of structures
Advanced composite systems such as 3D woven fiber composites and lattice core sandwich structures can show remarkable specific strength and damage tolerance. One of the origins of such high performance behavior is believed to be topological intricacy of their microstructure. This class of advanced composites with either polymeric, metallic or ceramic materials find a wide ranging application envelope including armors, aircraft engines, leading edges and fuselage. Theoretical models alone cannot be used to comprehend the behavior of such systems, which encompass multiple interacting scales, geometrical and material nonlinearities, complex geometries, damage accumulations and possible phase change. Thus, numerical methods become an indispensable tool in these investigations. Our research interests spans in investigating these problems from a fundamental microscopic level developing multi-scale models faithful to the physics of the materials at extreme pressures and temperatures.
Multiphysics modeling refers to systems whose deformation is influenced by other physical fields such as electrostatics, electrokinetic or fluids. The complexity is starkly increased due to interaction of geometric, material and boundary condition nonlinearities.
One classic example under consideration is metallic systems undergoing stress corrosion cracking. Here we devise multiscale, multiphysics models to catch the initiation of failure. We develop finite element based coupled models and investigate the phenomena with experimental collaborators who are leaders in high fidelity synchroton imaging.
Another project involves understanding biofouling of fur like textured surfaces. Biological systems at small scales are inherently multiphysical involving a complex interplay between large deformation, material nonlinearity, interfacial phenomena, transport and chemical behavior. Such interplay often results in fascinating functional enhancements. These include ability of biofilms to resist detachment from surfaces and anti-fouling properties of furs. Understanding and characterizing the coupled physics of such systems can unravel the fundamental factors that drive such phenomena. In our lab, we have developed coupled multiphysics methods to investigate such problems in silico. The insights can be used to design biomimetic systems capable of exhibiting extreme functionality.
Inspired by biological systems, we are designing structures which can be tuned real time. We focus on the interaction of real time tunability with material behavior. This will be used to design materials for robotics and autonomous systems manufacturing. Here we use a combination of phase change materials and topology to create real time changeable behavior in mechanical performance.