zur Erlangung des Grades des Doktors der Ingenieurwissenschaften

The benefits of replacing space and energy consuming actuators and sensors with so-called “active” materials have been well known for decades. One such material, shape memory alloys (SMAs), inspire particularly novel applications because of their unmatched power density, high force output, and ability to be multifunctional – acting simultaneously as both actuator and sensor. Recently, improved material processing techniques by companies such as Dynalloy have enabled repeatable, low-cost production of small-diameter (<100 µm) SMA wires capable of being actuated with minimal power at rates faster than 1 Hz. Additionally, a multifunctional power controller has been developed at North Carolina State University to simultaneously control the heating power input to SMA wires while measuring their changing electrical resistance. Advances such as these have enabled new applications to be considered in academia, such as steerable catheters and guidewires for use inside the human body, light-weight actuator systems for micro-air-vehicles, energy-efficient linear actuators to replace traditional solenoid or coil driven motors, and a multifunctional sensor-actuator system to control an adaptive Smart Inhaler nozzle without disrupting a delicate laminar air flow. Despite the obvious advantages and an abundance of novel application concepts, very few SMA-wire-based applications are commercially available. This development gap is caused by a number o