High voltage flexible glucose/O2 fully printed hydrogel-based enzymatic fuel cell

Herein we report on a novel enzymatic fuel cell (EFC) based on stencil printed electrodes modified with pyrrolo quinoline quinone glucose dehydrogenase and bilirubin oxidase, which are assembled by considering two different configurations: (i) normal assembling in liquid electrolyte and (ii) six EFCs connected in series, each one comprising both bioanode and biocathode, coupled through a hydrogel-based electrolyte in a stack-like mode similar to a Voltaic pile. After a deep electrodes characterization, they are assembled according to the first configuration obtaining an open circuit voltage (OCV) of 0.562 ± 0.002 V. Moreover, the EFC performance are substantially improved by using the second configuration (six EFCs connected in series) obtaining an OCV of 2.36 ± 0.22 V with a maximum power output of 22.9 ± 0.9 μW at a cell voltage of 1.95 V (operating in 10 mM D-glucose). This innovative approach represents a proof-of-concept towards the development of renewable power sources and could serve as a critical step in powering implantable bioelectronics, such as pacemakers.