A force sensor based on three weakly coupled resonators with ultrahigh sensitivity
A force sensor based on three weakly coupled resonators with ultrahigh sensitivity
A proof-of-concept force sensor based on three degree-of-freedom (DoF) weakly coupled resonators was fabricated using a silicon-on-insulator (SOI) process and electrically tested in 20 μTorr vacuum. Compared to the conventional single resonator force sensor with frequency shift as output, by measuring the amplitude ratio of two of the three resonators, the measured force sensitivity of the 3DoF sensor was 4.9 × 106/N, which was improved by two orders magnitude. A bias stiffness perturbation was applied to avoid mode aliasing effect and improve the linearity of the sensor. The noise floor of the amplitude ratio output of the sensor was theoretically analyzed for the first time, using the transfer function model of the 3DoF weakly coupled resonator system. It was shown based on measurement results that the output noise was mainly due to the thermal–electrical noise of the interface electronics. The output noise spectral density was measured, and agreed well with theoretical estimations. The noise floor of the force sensor output was estimated to be approximately 1.39nN for an assumed 10 Hz bandwidth of the output signal, resulting in a dynamic range of 74.8 dB.
MEMS, force sensor, resonant sensor, force sensitivity, thermal noise
151-162
Zhao, Chun
00e81968-02a9-4b1c-8b63-97aa9fbfd4e9
Wood, Graham S.
61de1458-e7f5-4712-925a-a95bb44580ee
Xie, Jianbing
130942fa-d891-40d0-bcb7-5dc548c56310
Chang, Honglong
5e79fc38-b84c-4e7b-aabe-dae9815cf324
Pu, Suan-Hui
8b46b970-56fd-4a4e-8688-28668f648f43
Kraft, Michael
c2ff2439-b909-4af3-824d-9d7c0d14dc3e
1 August 2015
Zhao, Chun
00e81968-02a9-4b1c-8b63-97aa9fbfd4e9
Wood, Graham S.
61de1458-e7f5-4712-925a-a95bb44580ee
Xie, Jianbing
130942fa-d891-40d0-bcb7-5dc548c56310
Chang, Honglong
5e79fc38-b84c-4e7b-aabe-dae9815cf324
Pu, Suan-Hui
8b46b970-56fd-4a4e-8688-28668f648f43
Kraft, Michael
c2ff2439-b909-4af3-824d-9d7c0d14dc3e
Zhao, Chun, Wood, Graham S., Xie, Jianbing, Chang, Honglong, Pu, Suan-Hui and Kraft, Michael
(2015)
A force sensor based on three weakly coupled resonators with ultrahigh sensitivity.
Sensors and Actuators A: Physical, 232, .
(doi:10.1016/j.sna.2015.05.011).
Abstract
A proof-of-concept force sensor based on three degree-of-freedom (DoF) weakly coupled resonators was fabricated using a silicon-on-insulator (SOI) process and electrically tested in 20 μTorr vacuum. Compared to the conventional single resonator force sensor with frequency shift as output, by measuring the amplitude ratio of two of the three resonators, the measured force sensitivity of the 3DoF sensor was 4.9 × 106/N, which was improved by two orders magnitude. A bias stiffness perturbation was applied to avoid mode aliasing effect and improve the linearity of the sensor. The noise floor of the amplitude ratio output of the sensor was theoretically analyzed for the first time, using the transfer function model of the 3DoF weakly coupled resonator system. It was shown based on measurement results that the output noise was mainly due to the thermal–electrical noise of the interface electronics. The output noise spectral density was measured, and agreed well with theoretical estimations. The noise floor of the force sensor output was estimated to be approximately 1.39nN for an assumed 10 Hz bandwidth of the output signal, resulting in a dynamic range of 74.8 dB.
Text
Zhao_A_force.pdf
- Accepted Manuscript
More information
Accepted/In Press date: 15 May 2015
e-pub ahead of print date: 1 June 2015
Published date: 1 August 2015
Keywords:
MEMS, force sensor, resonant sensor, force sensitivity, thermal noise
Organisations:
Nanoelectronics and Nanotechnology, Engineering Science Unit
Identifiers
Local EPrints ID: 378053
URI: http://eprints.soton.ac.uk/id/eprint/378053
ISSN: 0924-4247
PURE UUID: 0c6be5e5-f581-46b0-8a14-f0f1a02478f3
Catalogue record
Date deposited: 24 Jun 2015 14:00
Last modified: 15 Mar 2024 04:02
Export record
Altmetrics
Contributors
Author:
Chun Zhao
Author:
Graham S. Wood
Author:
Jianbing Xie
Author:
Honglong Chang
Author:
Michael Kraft
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
