Advanced Manufacturing of Intelligent Structures

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We had always imagined 2020 to be a perfect world where all complex engineering structures like planes, wind turbine blades, bridges, cars would detect and autonomously counteract external loads (weight, torque, winds) as well as internal anomalies (defects, failures) to ensure safety and economy during their entire service-life. What is it that prohibits the engineering structures of today from being intelligent - i.e. to sense and process a change in their surroundings and adapt themselves in accordance to this change? The answer is that today's structures are either: strong, adaptable, or lightweight. Reconfigurable aircraft structures require achieving all the three characteristics in a single material, which is the challenge we design engineers are facing for decades. Intelligent structures possessing the above characteristics mandate smart materials - materials whose physical properties can be altered by external stimuli like stress, moisture, electric and magnetic fields, light, temperature, and chemical substances - and a control system with an inbuilt feedback loop for autonomy. This research program proposes to resolve this conflict by merging advanced manufacturing of high-strength composites with additive manufacturing (AM) of smart materials to create control surfaces for reconfigurable aircraft. Inspired from the nature's growth and development, AM serves as the most pertinent fabrication tool for intelligent structures delivering organic and efficient complex geometries, which are a characteristic of an efficient bird flight, our inspiration from nature. As the airplanes, cars, wind turbine blades today are being manufactured from fiber reinforced polymer (FRP), integrating smart materials, for shape adaptation, during automated fiber placement of FRP would result in considerable weight and space savings. Structural health monitoring with embedded sensors during the production and service of the composite structures will help in efficient and timely repair and thus, enhanced product life cycle. Additionally, three-dimensionally (3D) printed electrical connections, would decrease the wire clutter. Control systems with closed feedback loop are essential to program the reconfiguration into the structures. But, the smart materials of today are inefficient and unreliable compared to their conventional mechanical rigid body alternatives and hence, do not satisfy the aircraft accreditation requirements for safety. My research program aims at developing these smart materials and improving their compatibility with the high strength materials for the design, optimization, and fabrication of intelligent structures. The know-how gained in this project can be directly applied to build intelligent structures for transportation, energy generation, and space; and other structural and functional composite components, especially in personalized equipment like prosthesis, rehabilitation-aid, exoskeletons, and sports equipment towards individuals.