Coupling enzymatic biopiles and physiological sensors by printing

This PhD is carried out in partnership with BeFC - Bioenzymatic Fuel Cells, a young start-up developing an enzymatic biopile and associated electronic platform, and the LGP2.

Enzymatic biofuel cells are currently being studied as an alternative to conventional batteries. The choice of materials based on their environmental impact is becoming essential in the design of these devices. Two major issues stand out for this thesis: the end-of-life and therefore production and use of conventional miniature batteries, which have a negative impact on the environment, and the use of numerous electronic components for connected devices, which are difficult to recycle. The thesis focused on printing the enzymatic biofuel cell on one side, and sensor printing on the other. The long-term aim is to couple the two systems, so that the printed biofuel cell powers the sensor system.

Initially, this work focused on the integration of an oxygen-reducing enzyme into a screen-printing ink. Complex challenges such as the accessibility of oxygen on the printed electrode, and the development of a functional, printable ink using environmentally friendly materials, were studied. The formulation of a bioactive ink and its printing on the (bio)cathode side was therefore the main subject of this section.

Subsequently, an ink formulation was developed for printing temperature sensors, in order to replace the sensors currently used on the electronic platform developed by BeFC. Paper substrates, specific for printed electronics, were studied and selected to replace the polymers usually used for these applications. Printing processes, in particular Aerosol Jet Printing, were selected and optimized for the application. Aerosol Jet Printing involved understanding and optimizing the ink and process parameters dedicated to this technology. In addition, an innovative development of paper-based biosensors to detect glucose concentration was also deployed at the end of the thesis.