Design, Optimisation and Predicted Performance of a Micro-Machined IR Sensor that Exploits the Squeeze Film Damping Effect to Measure Cantilever Beam Displacement

Smith, P D, Chatwin, C R and Young, R C D (2007) Design, Optimisation and Predicted Performance of a Micro-Machined IR Sensor that Exploits the Squeeze Film Damping Effect to Measure Cantilever Beam Displacement. Optics and Lasers in Engineering, 45 (4). pp. 503-522. ISSN 0143-8166

Full text not available from this repository.

Abstract

We describe the theoretical modelling of an infrared (IR) sensor based on an oscillating bi-material cantilever in which the beam is quantified as a function of the squeeze-film damping ratio, by measurement of the forced damped resonance frequency or phase angle. The structure under consideration is composed of a silicon nitride cantilever beam, coated with an upper gold absorbing layer. A detailed description of the optimisation of the cantilever geometry is described, with the gap height being identified as the critical parameter. The influence of the length, width, absorber gap and thickness of the two layers on signal-to-noise ratio (snr) is also discussed and an optimum configuration identified for each parameter. Phase modulation measurement techniques are found to provide the highest measurement resolution, with a thermal mechanical noise-limited performance of NE ¿T=0.21 mK, and an electronic noise-limited performance of NE ¿T=4 mK, being predicted for a 100×100 µm cantilever at 1 kHz measurement bandwidth.

Item Type: Article
Additional Information: This reports on a novel infared sensor based on an oscillating mems bi-material cantilever in which the beam is quantified as a function of the squeeze-film damping ratio, by measurement of the forced damped resonance frequency or phase angle. Phase modulation measurement techniques are found to provide the highest measurement resolution. This work was completed as part of a funded collaboration with Sensatech Ltd, contact tom@sensatech.com, tel: 01273-605964. Sensatech are currently working on device prototypes based on the design and performance that this paper predicts with a view to taking the technology into full production.
Schools and Departments: School of Engineering and Informatics > Engineering and Design
Depositing User: Chris Chatwin
Date Deposited: 06 Feb 2012 20:10
Last Modified: 30 Mar 2012 14:40
URI: http://sro.sussex.ac.uk/id/eprint/24391
📧 Request an update