This thesis presents a computational fluid dynamics (CFD) model of fluid flow driven by the motion of cilia, a cellular appendage found in organisms used to either move the fluid around them or to move themselves by propelling the fluid. Originating from an initial investigation to the flow patterns inside the third ventricle of a rat’s brain, this project expanded to improve the inadequacies of existing models of ciliary motion in fluid. This model was developed using the actuator line model to include the cilia motion to get an accurate representation of the cilia motion and its effect on the flow. This model not only provides exciting potential in various fields including soft robotics, biomedical research, environmental engineering, but also holds promise for drug delivery systems, and enhancing microfluidic designs. This thesis investigates the effect of the phase difference, the spacing and the frequency of the cilia motion on the fluid flow and the formation of the metachronal waves.

Shape memory alloys (SMAs) are a class of smart materials that can recover their predetermined shape when subjected to an appropriate thermal cycle. This unique property makes SMAs attractive for actuator applications, where the material’s phase transformation can be used to generate controlled motion or force. The actuator design leverages the one-way shape memory effect of NiTi (Nickel-Titanium) alloy wire, which contracts upon heating and recovers its original length when cooled. A bias spring opposes the SMA wire contraction, enabling a cyclical actuation motion. Thermal actuation is achieved through joule heating by passing an electric current through the SMA wire. This thesis presents the design of a compact, lightweight SMA-based actuator, providing controlled and precise motion in various engineering applications. A design of a soft actuator is presented exploiting the responses of the shape memory alloy (SMA) to trigger intrinsically mono-stable shape reconfiguration. The proposed class of soft actuators will perform bending actuation by selectively activating the SMA. The transition sequences were optimized by geometric parameterizations and energy-based criteria. The reconfigured structure is capable of arbitrary bending, which is reported here. The proposed class of robots has shown promise as a fast actuator or shape reconfigurable structure, which will bring new capabilities in future long-duration missions in space or undersea, as well as in bio-inspired robotics.