A chemical sensing microsystem utilizing an adaptive feedback circuit

Author

Fan, X.Z. ; Siwak, N.P. ; Kanakaraju, S. ; Richardson, C. ; Ghodssi, R.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Maryland, College Park, MD, USA

fYear

2009

fDate

21-25 June 2009

Firstpage

1007

Lastpage

1010

Abstract

For the first time, a chemical sensor utilizing optical MEMS with a novel adaptive feedback circuit is presented. This circuit implementation of a hill climbing feedback algorithm is capable of autonomously detecting resonant frequency shifts for a range of MEMS resonators. Eight different cantilever-based sensors (width = 0.6-1.4 mum, length = 40-75 mum, and thickness = 1.8 mum), resonating between 200 kHz to 600 kHz, have been measured. Additionally, the circuit has been used to track resonant frequency shifts due to isopropanol (IPA) adsorption on three different chemical sensors. The frequency detection range, measurement resolution, and sensitivity of the system have been evaluated.

Keywords

adsorption; cantilevers; chemical sensors; circuit feedback; micro-optomechanical devices; micromechanical resonators; microsensors; MEMS resonator; adaptive feedback circuit; cantilever-based sensor; chemical sensing microsystem; frequency 200 kHz to 600 kHz; hill climbing feedback algorithm; isopropanol adsorption; optical MEMS; resonant frequency shift detection; size 0.6 mum to 1.4 mum; size 1.8 mum; size 40 mum to 75 mum; Adaptive optics; Chemical sensors; Feedback circuits; Length measurement; Micromechanical devices; Optical feedback; Optical resonators; Optical sensors; RLC circuits; Resonant frequency; Feedback circuit; hill climbing algorithm; resonant frequency detection; resonator sensor;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International

Conference_Location

Denver, CO

Print_ISBN

978-1-4244-4190-7

Electronic_ISBN

978-1-4244-4193-8

Type

conf

DOI

10.1109/SENSOR.2009.5285958

Filename

5285958