3.2.4 Programmable reference parameters for resonance locking in electro-thermal piezoresistive cantilever sensor
- 20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019
2019-06-25 - 2019-06-26
- 3.2 MEMS-Sensoren
- A. Setiono, M. Fahrbach, J. Xu, W. Nyang’au, M. Bertke, H. Wasisto, E. Peiner - Technische Universität Braunschweig (Deutschland)
- 243 - 249
Resonant-frequency tracking is essential when measuring analyte targets using resonance-based sensors in real-time. We developed a self sensing and actuating silicon cantilever resonator that can be functionalized as an environmental sensor for analytes such as particles, humidity, and gases. However, direct thermal parasitic causes the sensor to generate a non-ideal output signal which hinders implementing a real-time phase-locked loop (PLL) based setup. To alleviate these problems, software de-embedding solutions to create an optimized signal, especially a monotonic phase response, are investigated. The de-embedding approach is based on subtracting a selectable reference, which mimics the parasitic behavior, from the measured data. All reference calculations are performed real-time on a microcontroller, which allows for on-line PLL based frequency tracking. Experiment results show a good response in resonant-frequency locking and tracking under exposure to cigarette smoke.