2015 Theses Doctoral

Advanced Transducers

Hurst, Adam

Sensing the world around us is fundamental to modern life. Since the advent of micro-scale, batch-fabricated sensors, we now interact with sensors in an array of consumer electronics, such as smart phones, watches and other wearables, and we rely on sensors for control and monitoring of complex systems, such as cars, jet engines, fossil fuel and renewable power generation as well as industrial processes. Sensors enable the internet-of-things; they are defining what we can measure within our data driven society. As the number of sensors produced increases, we seek to further innovate and scale sensor technologies with the key economic drivers being improved sensor performance and functionality, better system integration and characterization, reduced sensor size and power consumption, improved manufacturability and reduced cost.
This thesis presents a brief history and overview of state-of-the-art microelectromechanical systems (MEMS) strain, pressure and acceleration sensors followed by new advancements in dynamic pressure measurements and the characterization of dynamic pressure transducers. Accurate dynamic pressure measurement is vital to proper system design and operation, such as active control and system health monitoring of gas turbines. This work presents several dynamic pressure characterization techniques in gases and liquids. Applying these characterization methodologies, the frequency response of pressure transducers and pressure measurement systems are experimentally determined. These tools along with several analytical modeling techniques are further employed in the development of static pressure compensation for differential pressure transducers, low-pass filtering to prevent aliasing and real-time, analog active frequency response correction for aerodynamically-driven resonances in pressure transducers.
In addition to these advancements, this work explores nano-scale strain, pressure and acceleration sensors employing 2D materials. The 2D materials used within these innovative transducers include graphene and molybdenum disulfide (MoS2). Detailed electrical and mechanical characterization of both materials are presented with unique test methodologies. This work provides the design, modeling and fabrication processes for these 2D material-based sensors. Application specific packaging and test methodologies are included. This thesis further compares commercially available MEMS sensors and 2D material-based sensors.