Design-RF gas sensor-PHDthesis-2014


PhD subject 2014


Design and characterization of a novel carbon Microwave-based

Ultrasensitive gas Sensor



MDA group – IMS-Bordeaux Lab

in France (Intégration du Matériau au Système) is well recognized for its contribution in the area of microsensors and microsystems targeting health and environmental applications. The group was among the pioneers in the field of polymeric microfluidics combined with « Surface acoustic wave » (SAW) devices and were among the first to demonstrate the significant benefits of such an approach [1, 2].


(Micro et Nanotechnologies pour

Composants Optoélectroniques et Microondes) developed for about fifteen years EM-based modeling and design methodologies applied to the study of new RF and optoelectronic devices. A strong collaboration with

CINTRA in Singapore

( C NRS I nternational N TU T HALES R esearch A lliance) and


(Institute of Electronic, Microelectronic and Nanotechnology) was established for this ANR

(Agence Nationale de la Recherche) project. CINTRA has been actively working on fabrication of flexible electronics for numerous years (see fig. 1) [3] and has extended capabilities and expertise in printed technology and carbon nanotubes (CNTs)-based high frequency devices. IEMN lab is internationally recognized for their numerous contributions in the field of graphene material growth and devices fabrication for high frequency applications.

The combination of the unique knowledge of these

Figure 1.

Fabrication of prototype RF sensors by ink-jet printing on flexible substrate (paper) and

CNTs-based resonator realized at



four labs will open the way to design, fabrication, and measurement of novel CArbon and

Microwave-based Ultrasensitive gas Sensors (CAMUS).

This new type of sensor will: 1/ incorporate promising carbon materials as highly sensitive and selective element in the microwave band, 2/ be printed on flexible substrates such as Kapton and hydrophilic paper and 3/ be based on electromagnetic (


) transduction to facilitate its integration into a network of communicating sensors and to minimize energy consumption.

This PhD subject is devoted to evaluate by simulation and characterization the ability of sensor sensitivity (gas detection) based on EM transduction thanks to conductivity property change of the graphene or/and CNTs sensitive layers upon introduction of tested gases. Work will be organized in three major phases:

I.1) Realization of electronics and instrumentation for the characterization of the sensing structures and the evaluation of their performance for gas detection. The preliminary test cell is an important step for modelling and understanding the behavior of carbonaceous materials at very high frequencies under different gaseous atmospheres.

I.2) Study of EM software tools (HFSS, Comsol, etc) and of RF/microwave structures, to define a class of geometry adapted to sensing applications. Multi-physics modelling tools, which use full-wave EM

field simulation, are essential for understanding and studying of new designs of high frequency components. Such tools offer multiple state-of-the-art solver technologies based on either the proven finite element method or the well-established integral equation method. We have to select the appropriate solver for the type of simulation to perform on RF/microwave components.

II) Full-wave EM field simulation of preliminary designed gas sensor on different flexible substrates

(paper and kapton). The skills and know-how so acquired will allow the full-wave EM field simulation of one suitable sensor geometry with selected substrate and with sensitive layers of CNTs and graphene.

III) Finally, to carry out tests in a controlled environment to determine the sensor performance for gas detection in terms of sensitivity, linearity, selectivity and to evaluate the influence factors such as temperature and relative humidity, which represent major potential interferents.

[1] V. Raimbault, D. Rebière, C. Dejous, M. Guirardel, V. Conédéra, Acoustic Love wave platform with PDMS microfluidic chip,

Sensors & Actuators: A. Physical, 142 (1), 160-165, 2008.

[2] H. Tarbague et al., PDMS (Polydimethylsiloxane) Microfluidic Chip Molding for Love Wave Biosensor, j. Integrated Circuits and Systems (2010); v.5 pp.125-133.

[3] S. Pacchini, K. Frigui, S. Bila, C.A. Macuri, C. Brun, E. Flahaut, D. Baillargeat, T.B. Kang, CNTs effects on RF Resonator

Printed on Paper, Conf. IEEE and MTT-S, Intern. Microwave Symposium (IMS), 2013.


Entry requirements:

Candidates should have a minimum first or upper second class honours degree (or equivalent) in a suitable branch of Engineering.

We are looking for a motivated, talented student ready to deal with a multidisciplinary scientific field in the frame of a national and international collaboration. Good knowledge of physics and in particular electronics (design) is necessary.

The research will take place at IMS (Bordeaux) and XLIM (Limoges), with shared co-supervision. The proposed study is at the leading edge of a new area of research with large potential in our groups.

Start month:

1st September 2014

/Study Duration: Three


/Study mode:

Full Time.


PhD in electronic Engineering

/ Value:

The successful applicant will receive a stipend between 1382€ and 1657€ per month for 3 years.

Application deadline: 30/ 08/2014


Candidates should send CV, cover letter, and contact information for two references, as well as any information considered as relevant to promote the application (transcripts, …etc), to :

Corinne DEJOUS



(Assistant Professor)

E-mail :

[email protected]

, [email protected]

Phone :

+33 5 40 00 28 48, +33 5 40 00 27 73

Laboratoire de l’Intégration du Matériau au Système IMS , team MDA

Bordeaux University – Bât.A31, 351 cours de la Libération, 33405 TALENCE Cedex, France