Easter Presentation
Transcript: Feedthrough Cancellation Open Loop Characterisation 10 micron thick DC bias with AC signal Components: Transimpedance amplifier Feedthrough cancellation stage Bandpass filter Comparator Actuation & Sensing Principles Oscillator Circuit Implementation Actuation 1-port 2-port Differential drive Sensing Capacitive Piezoresitive Deviation = ±3 Hz Results Nodes = blue Antinodes = red Project Stages Filter-based Gravimetric Method (EU) Implement oscillator on one PCB Test with airborne particulates Adsorption Desorption Thermal compensation Functionalisation for specificity Results Results Detecting particulates with a portable MEMS resonator Electroacoustic Biosensors Combining Circuit Stages AQEG, “Particulate Matter in the UK: Summary”, Defra, London, 2005 C. Stanger, “DEFRA Report: Intercomparison between the TEOM analyser and the European reference sampler for the determination of PM10 concentrations”, Ref: CS/AQ/AD102099, University of Birmingham, 2004 P. S. Waggoner, H. G. Craighead, “Micro- and Nanomechanical Sensors for Environmental, Chemical, and Biological Detection”, Lab Chip, 2007, 7:1238–1255 A. T.-H. Lin, J. E.-Y. Lee, J. Yan, A. A. Seshia, “Methods for enhanced electrical transduction and characterization of micromechanical resonators”, Sensors and Actuators A, 2010, 158:263-272 Y.-W. Lin, S. Lee, S.-S. Li, Y. Xie, Z. Ren, C. T.-C. Nguyen, “Series-Resonant VHF Micromechanical Resonator Reference Oscillators”, IEEE J. Solid-State Circuits, 2004, 39:2477-2491 Open Loop Testing By Ben Kirby Supervised by Dr Ashwin Seshia and Abhinav Prasad SE Future Work Remove the effect of parasitic capacitance Differential piezoresistive sensing Device Topology Comparator Requirements: Loop gain > 1 Loop phase = multiple 360 deg Phase drop at resonance > 90 deg References MEMS Film Bulk Acoustic Resonator Bandpass Filter Tapered Element Oscillating Microbalance (UK) WG Motivation Resonator Sensitivity = 3 Hz/ng Circuit Design