dr. K.M. Dowling
Electronic Instrumentation (EI), Department of Microelectronics
Expertise: Wide-bandgap Electronics: Sensors, MEMS, and Power Devices
Themes: Merging (Ultra)-Wide bandgap Sensors with Integrated CircuitsBiography
Dr. Karen Dowling was born in Seattle, USA in 1991 and grew up in Ann Arbor, Michigan. She recieved her B.S. degree in electrical engineering from the California Institute of Technology in 2013. She obtained her M.S. and PhD in EE from Stanford University in California, USA in 2015 and 2019, respectively. Her thesis focused on creating high quality magnetometers for extreme environments using Gallium Nitride, as well as some micromachining techniques in Silicon Carbide, both wide bandgap semiconductors. Before joining TU Delft, she was a postdoctoral researcher at Lawrence Livermore National Laboratory (LLNL), expanding her work to RF opto-electronic power devices known as photo-semiconductor switches. She joined TU Delft as an assistant professor in August 2022. In the Department of Microelectronics , Dr. Dowling is excited to combine both her love of sensors for harsh environments with optically coupled conduction mechanisms to open new avenues for high performing microsensors across the spectrum from fundamental research to device development and (someday) deployment.
Karen was awarded a National Science Foundation Graduate Research Fellowship in 2015, and in 2023 was awarded the 2022 Marie Skłodowska-Curie Postdoctoral Fellowship.
EE2G1 Electrical Engineering for the Next Generation
BSc 2nd year project
ET4260 Microsystem integration
- Inverted Pyramid 3-axis Silicon Hall Effect Magnetic Sensor With Offset Cancellation
Jacopo Ruggeri; Udo Ausserlechner; Helmut Köck; Karen Dowling;
Microsystems & Nanonengineering,
Jan 2025. accepted for publication.
Abstract: ...
Microelectronic magnetic sensors are essential in diverse applications, including automotive, industrial, and consumer electronics. Hall-effect devices hold the largest share of the magnetic sensor market, and they are particularly valued for their reliability, low cost and CMOS compatibility. This paper introduces a novel 3-axis Hall-effect sensor element based on an inverted pyramid structure, realized by leveraging MEMS micromachining and CMOS processing. The devices are manufactured by etching the pyramid openings with TMAH and implanting the sloped walls with n-dopants to define the active area. Through the use of various bias-sense detection modes, the device is able to detect both in-plane and out-of-plane magnetic fields within a single compact structure. In addition, the offset can be significantly reduced by one to three orders of magnitude by employing the current-spinning method. The device presented in this work demonstrated high in-plane and out-of-plane current- and voltage-related sensitivities ranging between 64.1 to 198 V A^−1 T^−1 and 14.8 to 21.4 mV V^−1 T^−1, with crosstalk below 4.7 %. The sensor exhibits a thermal noise floor which corresponds to approximately 0.5 μV√Hz at 1.31 V supply. This novel Hall-effect sensor represents a promising and simpler alternative to existing state-of-the-art 3-axis magnetic sensors, offering a viable solution for precise and reliable magnetic field sensing in various applications such as position feedback and power monitoring.
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Last updated: 4 Nov 2024
Karen Dowling
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- Room: HB 14.060
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