J. Launay

Design, realization and characterization of all-arround SiO2/Al 2 O 3 gate, suspended silicon nanowire chemical field effect transistors

We present a sensor platform associated to silicon-nanowire chemical field effect transistors (Si-nw-ChemFET). Innovations concern the use of networks of suspended silicon N+/P/N+ nanowires as conducting channel, the realization by thermal oxidation and Atomic-Layer Deposition (ALD) of a SiO2/Al2O3 gate insulator all-around the silicon nanowires, and their final integration into covered SU8-based microfluidic channels. The Si-nw-MOSFET/ChemFET fabrication process and electrical/electrochemical characterizations are presented. The fabrication process did not need an expensive and time-consuming e-beam lithography, but only fast and low cost standard photolithography protocols. Such microdevice will provide new opportunities for biochemical analysis at the micro/nanoscale.

Ring nanoelectrodes integrated into microwell arrays for the analysis of mitochondria isolated from leukemic cells

We report here the fabrication and the electrochemical characterization of recessed disk microelectrodes (rDME) and recessed ring nanoelectrodes (rRNE) integrated into microwell arrays. The technological process based on the reactive ion etching of a SiO 2 /Ti/Pt/Ti/SiO 2 stack is optimized in order to realize functional electrochemical microdevices on glass substrate and so, enable the coupling of amperometric measurements with optical analysis. Multiphysic simulations and electrochemical characterizations are carried out to study and enhance the amperometric performances of recessed ring nanoelectrodes arrays (rRNEA) according to their geometry. Finally, all these results demonstrate that rRNEA are fitted for the detection of bio-electrochemical species at the microscale and consequently, for the analysis of the metabolic status of isolated mitochondria through the measurement of dissolved oxygen and hydrogen peroxide.

Organic photodiode for detection of herbicides in water using microalgal photosynthesis

The growing interest for monitoring the quality of water has triggered the need of fast, portable and cheap detection systems. To answer this problematic, we developed a lab on a chip for herbicide detection based on micro algal photosynthesis. A blue organic light-emitting diode is used as the excitation source while the resulting algae luminescence is monitored using an organic photodiode (OPD). During the OPD optimization process, a correlation between fullerene acceptor concentration and dark current was supposed. Using a blend of DTS(PTTh2)2:PC60BM without interfacial layers result in dark current lower than 10−6 mA/cm2 at −2 V and EQE higher than 50% in the region of interest.

Design, realization and characterization of silicon nanowire ion sensitive field effect transistors

The aim of our research project is to achieve a potentiometric multi-sensor platform, consisting of ion sensitive field effect transistors ISFET and MOSFET, which channel is a nanowire or a network of horizontal Silicon nanowires and whose gate insulator is alumina AhO3 deposed by Atomic Layer deposition ALD. This microdevice will provide chemical and biological analyses in the liquid phase, in microfluidic channels.

Nanotechnology practical teaching at school and university

In the last two decades, the teaching of microelectronics and nanotechnologies has become more and more challenging. First, numerous fundamental sciences converge, which implies the introduction of more and complex theoretical concepts, from simple electronic to quantum mechanics, as well as from chemistry, biology, medicine, … Here, we present our teaching experience in short practical training programs adapted for secondary and university students where they confront their theoretical background to real life, i.e. by elaborating and testing their own micro/nano-system for a specified functionality.

Novel sensors for the Artificial Mouth

Similarly to human chewing, tasty compounds are released in saliva during the food piece mastication in the ‘Artificial Mouth’, and so, are available continuously. Glutamate is present in numerous food, as taste enhancer, has a nice and sought “umami” taste, specific receptors and different inter individual sensitivities, and is a fair marker of the release of tasty compounds. The three sensors (for pH, salt, or glutamate concentration) have the same size, so they are easily interchangeable. Up to now, only one kind of parameter may be analysed at a time by the different sensors. Nevertheless, combined electrodes may be developed in the future.

Polysiloxane Thin Films Optimisation for Potassium Detection using EIS Characterisation with Microelectrode Structures

Most chemical or biochemical analysis use current-voltage I(V) characterization as detection principle. Thus, the development of microelectrodes using standard silicon technologies process is required: they show advantages of mass production, generic structure, small dimensions, low cost, and are well adapted for the detection of chemical, biochemical or biological species in aqueous environment using specific impedimetric measurement methods.