Photoacoustic trace gas sensing using a miniature 3D printed gas cell

Research output: Contribution to conferenceSpeech

Abstract

Photoacoustic spectroscopy (PAS) as a measurement method for trace gas detection has the inherent property of favourable signal levels with reduction of the gas cell diameter. Approaches in miniaturisation have so far been presented through miniature milling or waver bonding, with the overall technique being employed for leak detection in industrial applications or diagnostics in medical and biological applications. We will present a further miniaturisation approach by using a 3D printed miniature PAS gas cell in combination with off-the-shelf fibre optics and MEMS membrane microphones. To achieve a low cost, small scale system, rapid prototyping fabrication is used with a stereolithography 3D printer (EnvisionTec Prefactory Desktop Aureus), building the 3D printed gas cell in one piece using laser induced polymerisation of an acrylic resin. The resonant PAS gas cell has a cylindrical acoustic resonator of 9.86mm length and 0.9mm radius, acoustic buffer volumes connected at the end of the open resonator and integrated holders for two fibre coupled gradient index (GRIN) lens collimators creating the optical interrogation path. Multiple miniature MEMS membrane microphones (Wolfson Microelectronics WM7131) are connected to the middle of the resonator to detect the pressure changes induced by modulation of the interrogating laser source at the first longitudinal acoustic resonance of the cell, therefore, amplifying the signal by the Q-factor of the resonant cell. The overall outer dimensions of the gas cell are less than 15mm x 25mm x 29mm.
We present our latest results on detection limits of the 3D printed gas sensor, using fibre coupled DFB lasers for interrogation of gas species in the NIR and quantitative measurements with calibrated gas mixtures. A further focus will be on integration of amplitude modulation techniques using, for example, a semiconductor optical amplifier and additional steps to increase signal sensitivities and aid system integration.

Conference

ConferencePhoton14
CountryUnited Kingdom
CityLondon
Period1/09/144/09/14
Internet address

Fingerprint

cells
gases
photoacoustic spectroscopy
resonators
interrogation
miniaturization
microphones
microelectromechanical systems
membranes
lasers
acoustic resonance
rapid prototyping
systems integration
acrylic resins
fibers
acoustics
printers
collimators
holders
shelves

Keywords

  • photoacoustic spectroscopy (PAS)
  • 3D printing
  • miniaturisation
  • PAS gas cells

Cite this

@conference{e43a193644c94aa4bb80a133c78fb371,
title = "Photoacoustic trace gas sensing using a miniature 3D printed gas cell",
abstract = "Photoacoustic spectroscopy (PAS) as a measurement method for trace gas detection has the inherent property of favourable signal levels with reduction of the gas cell diameter. Approaches in miniaturisation have so far been presented through miniature milling or waver bonding, with the overall technique being employed for leak detection in industrial applications or diagnostics in medical and biological applications. We will present a further miniaturisation approach by using a 3D printed miniature PAS gas cell in combination with off-the-shelf fibre optics and MEMS membrane microphones. To achieve a low cost, small scale system, rapid prototyping fabrication is used with a stereolithography 3D printer (EnvisionTec Prefactory Desktop Aureus), building the 3D printed gas cell in one piece using laser induced polymerisation of an acrylic resin. The resonant PAS gas cell has a cylindrical acoustic resonator of 9.86mm length and 0.9mm radius, acoustic buffer volumes connected at the end of the open resonator and integrated holders for two fibre coupled gradient index (GRIN) lens collimators creating the optical interrogation path. Multiple miniature MEMS membrane microphones (Wolfson Microelectronics WM7131) are connected to the middle of the resonator to detect the pressure changes induced by modulation of the interrogating laser source at the first longitudinal acoustic resonance of the cell, therefore, amplifying the signal by the Q-factor of the resonant cell. The overall outer dimensions of the gas cell are less than 15mm x 25mm x 29mm.We present our latest results on detection limits of the 3D printed gas sensor, using fibre coupled DFB lasers for interrogation of gas species in the NIR and quantitative measurements with calibrated gas mixtures. A further focus will be on integration of amplitude modulation techniques using, for example, a semiconductor optical amplifier and additional steps to increase signal sensitivities and aid system integration.",
keywords = "photoacoustic spectroscopy (PAS) , 3D printing, miniaturisation, PAS gas cells",
author = "Ralf Bauer and George Stewart and Walter Johnstone and Michael Lengden",
year = "2014",
month = "9",
language = "English",
note = "Photon14 ; Conference date: 01-09-2014 Through 04-09-2014",
url = "http://www.photon.org.uk/home",

}

Photoacoustic trace gas sensing using a miniature 3D printed gas cell. / Bauer, Ralf; Stewart, George; Johnstone, Walter; Lengden, Michael.

2014. Photon14, London, United Kingdom.

Research output: Contribution to conferenceSpeech

TY - CONF

T1 - Photoacoustic trace gas sensing using a miniature 3D printed gas cell

AU - Bauer, Ralf

AU - Stewart, George

AU - Johnstone, Walter

AU - Lengden, Michael

PY - 2014/9

Y1 - 2014/9

N2 - Photoacoustic spectroscopy (PAS) as a measurement method for trace gas detection has the inherent property of favourable signal levels with reduction of the gas cell diameter. Approaches in miniaturisation have so far been presented through miniature milling or waver bonding, with the overall technique being employed for leak detection in industrial applications or diagnostics in medical and biological applications. We will present a further miniaturisation approach by using a 3D printed miniature PAS gas cell in combination with off-the-shelf fibre optics and MEMS membrane microphones. To achieve a low cost, small scale system, rapid prototyping fabrication is used with a stereolithography 3D printer (EnvisionTec Prefactory Desktop Aureus), building the 3D printed gas cell in one piece using laser induced polymerisation of an acrylic resin. The resonant PAS gas cell has a cylindrical acoustic resonator of 9.86mm length and 0.9mm radius, acoustic buffer volumes connected at the end of the open resonator and integrated holders for two fibre coupled gradient index (GRIN) lens collimators creating the optical interrogation path. Multiple miniature MEMS membrane microphones (Wolfson Microelectronics WM7131) are connected to the middle of the resonator to detect the pressure changes induced by modulation of the interrogating laser source at the first longitudinal acoustic resonance of the cell, therefore, amplifying the signal by the Q-factor of the resonant cell. The overall outer dimensions of the gas cell are less than 15mm x 25mm x 29mm.We present our latest results on detection limits of the 3D printed gas sensor, using fibre coupled DFB lasers for interrogation of gas species in the NIR and quantitative measurements with calibrated gas mixtures. A further focus will be on integration of amplitude modulation techniques using, for example, a semiconductor optical amplifier and additional steps to increase signal sensitivities and aid system integration.

AB - Photoacoustic spectroscopy (PAS) as a measurement method for trace gas detection has the inherent property of favourable signal levels with reduction of the gas cell diameter. Approaches in miniaturisation have so far been presented through miniature milling or waver bonding, with the overall technique being employed for leak detection in industrial applications or diagnostics in medical and biological applications. We will present a further miniaturisation approach by using a 3D printed miniature PAS gas cell in combination with off-the-shelf fibre optics and MEMS membrane microphones. To achieve a low cost, small scale system, rapid prototyping fabrication is used with a stereolithography 3D printer (EnvisionTec Prefactory Desktop Aureus), building the 3D printed gas cell in one piece using laser induced polymerisation of an acrylic resin. The resonant PAS gas cell has a cylindrical acoustic resonator of 9.86mm length and 0.9mm radius, acoustic buffer volumes connected at the end of the open resonator and integrated holders for two fibre coupled gradient index (GRIN) lens collimators creating the optical interrogation path. Multiple miniature MEMS membrane microphones (Wolfson Microelectronics WM7131) are connected to the middle of the resonator to detect the pressure changes induced by modulation of the interrogating laser source at the first longitudinal acoustic resonance of the cell, therefore, amplifying the signal by the Q-factor of the resonant cell. The overall outer dimensions of the gas cell are less than 15mm x 25mm x 29mm.We present our latest results on detection limits of the 3D printed gas sensor, using fibre coupled DFB lasers for interrogation of gas species in the NIR and quantitative measurements with calibrated gas mixtures. A further focus will be on integration of amplitude modulation techniques using, for example, a semiconductor optical amplifier and additional steps to increase signal sensitivities and aid system integration.

KW - photoacoustic spectroscopy (PAS)

KW - 3D printing

KW - miniaturisation

KW - PAS gas cells

UR - http://www.photon.org.uk/home

M3 - Speech

ER -