Fermentation based carbon nanotube multifunctional bionic composites.
The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.
Dipartimento di Ingegneria Civile e Ambientale, Università di Perugia, UdR INSTM, Strada di Pentima 4, I-05100 Terni, Italy.
Luca
L
Valentini
Dipartimento di Ingegneria Civile e Ambientale, Università di Perugia, UdR INSTM, Strada di Pentima 4, I-05100 Terni, Italy.
Silvia Bittolo
SB
Bon
Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, I-38123 Trento, Italy.
Stefano
S
Signetti
Centre for Materials and Microsystems, Fondazione Bruno Kessler, via Sommarive 18, I-38123 Trento, Italy.
Manoj
M
Tripathi
Centre for Materials and Microsystems, Fondazione Bruno Kessler, via Sommarive 18, I-38123 Trento, Italy.
Erica
E
Iacob
Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, I-38123 Trento, Italy.|Centre for Materials and Microsystems, Fondazione Bruno Kessler, via Sommarive 18, I-38123 Trento, Italy.|School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom.
Nicola M
NM
Pugno
D018441:Biofilms; D004553:Electric Conductivity; D005285:Fermentation; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000382:microbiology / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000166:cytology / Q000254:growth & development*; D013499:Surface Properties; D013718:Tensile Strength
D037742:Nanotubes, Carbon