Flexible Electronics Department Provence Microelectronics Center
Postdoctoral fellowship in instrumentation of organic bioelectronic devices
Mines Saint-Etienne is a graduate engineering school of the Institut Mines-Télécom (IMT), the leading public group of engineering and management schools in France. IMT is an EPSCP (large establishment) under the supervision of the Ministry of the Economy, Finance and Industrial and Digital Sovereignty. The École Nationale Supérieure des Mines de Saint-Étienne (Mines Saint-Etienne) is responsible for training, research and innovation, transfer to industry and scientific, technical and industrial culture.
Mines Saint-Etienne represents: 2,400 engineering students and researchers in training, 480 staff (150 researchers and teacher-researchers), a consolidated budget of €46 million, 3 campuses dedicated to industry in Saint-Etienne and Lyon (region AURA), to microelectronics and connected objects in Gardanne (Aix-Marseille Provence area, region PACA) and to engineering for health in Saint-Etienne; 6 research units; 5 training and research centers; a leading technical and industrial scientific culture center in France “La Rotonde” (> 50,000 visitors / year).
The Provence Microelectronics Center (CMP) is located in Gardanne (in Bouches-du-Rhône, 13). It is one of Mines Saint-Etienne’s five training and research centers. It includes four departments including the Flexible Electronics department (FEL) within which the post-doctoral fellowship is open. Since 2005, the FEL department has been interested in activities relating to hybrid electronic systems. Most of the work is carried out around communicating electronic systems made on flexible substrates. At the technological level, research is carried out in the School's clean room in partnership with the Micropacks and IDFab technological platforms. The areas of application affect all sectors of society, in connection with sensor networks (medical patches for patient monitoring, abandoned sensors for the environment), advanced human-machine interfaces, etc.
Scientific Context and Objectives
Ultra-flexible, conformable and implantable organic electronic devices incorporating artificial intelligence promise to revolutionize real-time monitoring and treatment of chronic diseases. Such devices could be based on organic electrochemical transistors (OECTs) exploiting mixed ion-electron polymer conductors (PMIECs) as active layers. Indeed, PMIECs have emerged as an excellent hardware platform for interfacing biology with conventional electronics; identified as the “organic or plastic bioelectronics” field. The organic electrochemical transistor (OECTs) is considered one of the key elements to make such transduction. Its efficiency is evaluated through few Figures of Merit (FoM): i) transconductance (gm), ii) switching times (ionic vs. electronic), iii) in situ imaging of the dedoping propagation front ( for example, measurement of ionic mobility), iv) the electrochemical impedance to establish the equivalent electrical circuit and extract the capacitance. The control of hierarchical self- organization and the choice of the most favorable morphology in PMIECs are of paramount importance to improve the functioning of OECTs transduction. Beyond transduction applications, in the longer term, OECT is interesting for creating emerging applications in neuromorphic or bioelectronic circuits. Simple inverters have been presented in a CMOS type configuration. This provides a promising basis for studying advanced circuits.
Our current understanding shows that the swelling (or ionic penetration) properties of these (macro)molecular PMIECs are essential to properly drive OECTs. Indeed, the swelling of the rich hydrophilic (hence ionic) phases allows the ions to penetrate and move in the vicinity of the rich hydrophobic p-conjugated phases, modulating their doping states and therefore the quantity of electronic current circulating in the OECTs channel. Therefore, the total surface area exchanged between ionic and p-conjugated phases and their self-organization play a central role since such transduction takes place throughout the volume of the channel layer of an OECT.
