Silicon micro-levers and a multilayer graphene membrane studied via laser photoacoustic detection

0443981 - ÚFCH JH 2016 RIV DE eng J - Článek v odborném periodiku
Zelinger, Zdeněk - Janda, Pavel - Suchánek, Jan - Dostál, M. - Kubát, Pavel - Nevrlý, V. - Bitala, P. - Civiš, Svatopluk
Silicon micro-levers and a multilayer graphene membrane studied via laser photoacoustic detection.
Journal of Sensors and Sensor Systems. Roč. 4, č. 1 (2015), s. 103-109. ISSN 2194-8771
Grant CEP: GA ČR(CZ) GA14-14696S
Grant ostatní: AV ČR(CZ) R200401401; COST(XE) TD1105
Institucionální podpora: RVO:61388955
Klíčová slova: TRACE GAS-ANALYSIS * MONOLAYER GRAPHENE * CANTILEVER ARRAY
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie

Laser photoacoustic spectroscopy (PAS) is a method that utilizes the sensing of the pressure waves that emerge upon the absorption of radiation by absorbing species. The use of the conventional electret microphone as a pressure sensor has already reached its limit, and a new type of microphone – an optical microphone – has been suggested to increase the sensitivity of this method. The movement of a micro-lever or a membrane is sensed via a reflected beam of light, which falls onto a position-sensing detector. The use of one micro-lever as a pressure sensor in the form of a silicon cantilever has already enhanced the sensitivity of laser PAS. Herein, we test two types of home-made sensing elements – four coupled silicon micro-levers and a multilayer graphene membrane – which have the potential to enhance this sensitivity further. Graphene sheets possess outstanding electromechanical properties and demonstrate impressive sensitivity as mass detectors. Their mechanical properties make them suitable for use as micro-/nano-levers or membranes, which could function as extremely sensitive pressure sensors. Graphene sheets were prepared from multilayer graphene through the micromechanical cleavage of basal plane highly ordered pyrolytic graphite. Multilayer graphene sheets (thickness ~102 nm) were then mounted on an additional glass window in a cuvette for PAS. The movements of the sheets induced by acoustic waves were measured using an He–Ne laser beam reflected from the sheets onto a quadrant detector. A discretely tunable CO2 laser was used as the source of radiation energy for the laser PAS experiments. Sensitivity testing of the investigated sensing elements was performed with the aid of concentration standards and a mixing arrangement in a flow regime.
Trvalý link: http://hdl.handle.net/11104/0246590