Enhanced properties of Love wave microsensors with Inkjet-Printed graphene oxide layers
Résumé
We report for the first time, a novel coating method on Love wave devices, leading the highway for a new generation of acoustic components in plenty of technological applications, especially as environmental sensors. Functional oxide thin films such as Graphene Oxide (GO) layers were deposited by inkjet printing method. Devices with several (1 to 10) layers of GO, between the Inter-Digitated Transducers (IDTs) and over almost the entire top surface of the device, were studied, both experimentally and theoretically with a 3D finite element modeling tool. It was shown that enhanced properties were offered by amalgamating ultra-thin GO films with SiO2 and thus leading to optimized surface acoustic wave propagation. Indeed, SiO2 has been widely chosen in numerous works [1] and plenty of applications [2] as a guiding layer material, since it provides an appropriate surface, chemically more stable than polymer guiding layer materials. Then, the operational frequency was increased and the insertion losses were decreased whilst adding each new layer of GO on SiO2 resulting in an improved guiding layer. Furthermore, due to the exceptional properties of GO and among them the effective surface, it was recently shown [3] that, similar devices have a great potential as vapor detectors, allowing unmatched sensitivities. With such improved GO-on-SiO2 films, this method can meet the requirements of high demanding gas, liquid or biological sensing applications. In addition, inkjet-printed GO also offers an easy way of functionalization by chemically tailoring its properties, which may allow to customize conveniently generic multisensor chips for selectivity purposes. References [1]. Länge, K., Rapp, B. E., & Rapp, M. (2008). Surface acoustic wave biosensors: a review. Analytical and bioanalytical chemistry, 391(5), 1509-1519. [2]. Jakoby, B., & Vellekoop, M. J. (1997). Properties of Love waves: applications in sensors. Smart materials and structures, 6(6), 668. [3]. Nikolaou, I.; Hallil, H.; Dejous, C.; Rebiere, D.; Deligeorgis, G.; Conedera, V., "Inkjet - Printed graphene layer by layer on SAW devices for gas detection applications," in SENSORS, 2015 IEEE , vol., no., pp.1-4, 1-4 Nov. 2015, doi: 10.1109/ICSENS.2015.7370509. - See more at: http://www.european-mrs.com/2016-spring-symposium-y-european-materials-research-society#sthash.zEu5VDfO.dpuf