Design and fabrication of an integrated microbiology impendance sensor
Published : 11 October 2018
Monitoring of bacterial growth is critical in various environmental fields such as the drinkable water’s distribution. The design and fabrication of compact and portable sensors is thus crucial for efficient and continuous in-situ measurements.
With this objective in mind, the IMEP-LaHC and G2Elab laboratories are starting a collaboration to develop an integrated lab on chip to monitor bacterial concentrations. The originality of the project lies in the co-integration on a single glass substrate of two sensing microfluidic functions based on different physical principles (optical absorption1 and impedance spectroscopy2). The IMEP-LAHC, skilled in integrated optics and in radiofrequency, will be in charge of the opto-fluidic function and of the impedance spectroscopy measurements. The G2Elab will offer its expertise in electrode design, microfluidic polymer microsystems and ionic conduction. The IGE Institute3, as end-user, will validate the device by experimental measurements of bacterial concentrations.
The proposed internship is linked to the impedance spectrometry function and aims at designing a microfluidic cell with built-in electrodes to provide a first test-device for impedance measurement.
The student will be under the co-supervision of researchers of both IMEP-LaHC and G2Elab. The internship will fulfill two main objectives. The first goal will be to implement the envisaged manufacturing process of a microfluidic cell in polymer material. The second is to design and deposit stainless steel electrodes on a glass substrate. This last will then be bonded onto the microfluidic cell as a cover. If time permits, the chip will be tested with a bacterial suspension.
To fulfill these objectives, the student will be trained in the two laboratories for various techniques of design and fabrication. The training includes in particular:
– Polymer embossing for the microfluidic cell fabrication4
– Interdigital electrodes design
– Clean room processes for the electrode deposition and cover bonding
Leticia GIMENO – 04 76 82 63 77
Bâtiment GreEn-ER, 21 avenue des martyrs CS 90624 38031 Grenoble Cedex 1 – France
Elise GHIBAUDO – 04 56 52 95 31
laboratoire IMEP – LaHC
MINATEC – INPG, 3 Parvis Louis Néel BP 257 38016 Grenoble Cedex 1 – France
1 Geoffray F., Allenet T., Canto F., et al. Development of an Opto-fluidic Microsystem Dedicated to Chemical
Analysis in a Nuclear Environment. Procedia Chemistry, 2016, vol. 21, p. 453-460.
2 Xavier P., D. Rauly, E. Chamberod and J.M.F. Martins. 2017. Theoretical evidence of maximum intracellular
currents vs frequency in an Escherichia coli cell submitted to AC voltage. Bioelectromagnetics 38(3) : 213-219.
3 Institut des Géosciences de l’Environnement – CS 40700 38058 Grenoble Cedex
4 Fujii, T. (2002). PDMS-based microfluidic devices for biomedical applications. Microelectronic Engineering,