Staff directory

Clement Joseph Jean Hebert

Postdoctoral Researcher
Advanced Electronic Materials and Devices



  • Flexible Graphene Solution-Gated Field-Effect Transistors: Efficient Transducers for Micro-Electrocorticography

    Hébert C., Masvidal-Codina E., Suarez-Perez A., Calia A.B., Piret G., Garcia-Cortadella R., Illa X., Del Corro Garcia E., De la Cruz Sanchez J.M., Casals D.V., Prats-Alfonso E., Bousquet J., Godignon P., Yvert B., Villa R., Sanchez-Vives M.V., Guimerà-Brunet A., Garrido J.A. Advanced Functional Materials; 28 (12, 1703976) 2018. 10.1002/adfm.201703976.

    Brain–computer interfaces and neural prostheses based on the detection of electrocorticography (ECoG) signals are rapidly growing fields of research. Several technologies are currently competing to be the first to reach the market; however, none of them fulfill yet all the requirements of the ideal interface with neurons. Thanks to its biocompatibility, low dimensionality, mechanical flexibility, and electronic properties, graphene is one of the most promising material candidates for neural interfacing. After discussing the operation of graphene solution-gated field-effect transistors (SGFET) and characterizing their performance in saline solution, it is reported here that this technology is suitable for μ-ECoG recordings through studies of spontaneous slow-wave activity, sensory-evoked responses on the visual and auditory cortices, and synchronous activity in a rat model of epilepsy. An in-depth comparison of the signal-to-noise ratio of graphene SGFETs with that of platinum black electrodes confirms that graphene SGFET technology is approaching the performance of state-of-the art neural technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Graphene in the Design and Engineering of Next-Generation Neural Interfaces

    Kostarelos K., Vincent M., Hebert C., Garrido J.A. Advanced Materials; 29 (42, 1700909) 2017. 10.1002/adma.201700909. IF: 19.791

    Neural interfaces are becoming a powerful toolkit for clinical interventions requiring stimulation and/or recording of the electrical activity of the nervous system. Active implantable devices offer a promising approach for the treatment of various diseases affecting the central or peripheral nervous systems by electrically stimulating different neuronal structures. All currently used neural interface devices are designed to perform a single function: either record activity or electrically stimulate tissue. Because of their electrical and electrochemical performance and their suitability for integration into flexible devices, graphene-based materials constitute a versatile platform that could help address many of the current challenges in neural interface design. Here, how graphene and other 2D materials possess an array of properties that can enable enhanced functional capabilities for neural interfaces is illustrated. It is emphasized that the technological challenges are similar for all alternative types of materials used in the engineering of neural interface devices, each offering a unique set of advantages and limitations. Graphene and 2D materials can indeed play a commanding role in the efforts toward wider clinical adoption of bioelectronics and electroceuticals. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • Interfacing neurons on carbon nanotubes covered with diamond

    Seyock S., Maybeck V., Scorsone E., Rousseau L., Hébert C., Lissorgues G., Bergonzo P., Offenhäusser A. RSC Advances; 7 (1): 153 - 160. 2017. 10.1039/c6ra20207a. IF: 3.108

    A recently discovered material, carbon nanotubes covered with diamond (DCNTs) was tested for its suitability in bioelectronics applications. Diamond shows advantages for bioelectronics applications (wide electro chemical window and bioinertness). This study investigates the effect of electrode surface shape (flat or three dimensional) on cell growth and behavior. For comparison, flat nanocrystalline diamond substrates were used. Primary embryonic neurons were grown on top of the structures and neither incorporated the structures nor did they grow in between the single structures. The interface was closely examined using focused ion beam (FIB) and scanning electron microscopy. Of special interest was the interface between cell and substrate. 5% to 25% of the cell membrane adhered to the substrate, which fits the theoretical estimated value. While investigating the conformity of the neurons, it could be observed that the cell membrane attaches to different heights of the tips of the 3D structure. However, the aspect ratio of the structures had no effect on the cell viability. These results let us assume that not more than 25% of cell attachment is needed for the survival of a functional neuronal cell. © The Royal Society of Chemistry.