Graphene-Based Bionic Composites with Multifunctional and Repairing Properties.

In this work, a novel bionic composite inspired by the concept of yeast fermentation has been proposed. It was observed that the addition of graphene nanoplatelets during the fermentation of extract of Saccharomyces cerevisiae fungi allows coupling of the graphene sheets to the yeast cell wall. This process resulted in the formation of a composite film with improved mechanical and electrical properties along with the capability of converting the light stimulus in the electrical signal. The mechanical properties of the prepared composites, namely, the fracture strength and Young's modulus, were studied via numerical simulations and are related to the properties of the constituent phases via rules of mixture. Finally, it was observed that graphene nanoplatelets, added to the nutrient broth, were able to reassemble onto the stressed cell surface and repair the surface cracking, partially restoring the pristine electrical and mechanical properties. The method reported here may find potential application in the development of self-healable bioelectronic devices and microorganism-based strain and chemical biosensors.