Additive Manufacturing of Living Electrodes

The combination of electrochemically active microorganisms with miniaturized electronics has immense potential for augmenting a wide range of practical bioelectronic applications such as biosensing, bioenergy harvesting, and bio-electrosynthesis. However, a major challenge to the controllable and seamless integration of biological systems and external electronics is the fundamental mismatch in physicochemical properties and weak signal transmission between the biotic-abiotic interfaces. Here, we demonstrated an innovative method to fabricate the conductive-polymer-bacteria living electrode with a rapid and controllable 3-D printing platform and simple electrochemical polymerization techniques. The monomer precursor 3,4-ethylenedioxythiophene (EDOT) was printed into a 3-electrode electrochemical cell containing the exoelectrogen Shewanella oneidensis wild type MR-1. The monomer was in-situ electrochemically polymerized to the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), entrapping and connecting the electrochemically active bacteria to the electrode within 35 min. Using cyclic voltammetry (CV), the living electrode showed enhanced bio-electrochemical activities, providing transformative development for bioenergy harvesters, biosensors and biomedical devices.