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WITHDRAWN - SM03.08.03 : Disordered, Combinatorial Nano-Biosynthesis with Biofilms

5:00 PM–7:00 PM Apr 5, 2018

PCC North, 300 Level, Exhibit Hall C-E

Description
Sanhita Ray1 Dibakar Sahoo1 Anjan Dasgupta1

1, University of Calcutta, Kolkata, , India

The unit component of any electronic device consists of an electrical junction between two materials of dissimilar charge conductivity. Conventional device designs provide for a logical or geometric distribution of these junctions in space. However, in our search for bio-mimetic electronic circuits, there is little scope for applying geometric design strategies: most bio-circuitry (e.g. neuronal circuitry or nerve-muscle junctions) follow a fractal distribution. In order to effectively simulate biological information processing, in an artificial circuit, we need to achieve a disordered distribution of material junctions. Bacterial biofilms have provided a way to achieve this. We have used biofilms to incorporate both conducting nanomaterials (graphene [1] and carbon nanotubes) and inorganic semiconductors (zinc oxide), with photoluminescent properties, into a series of combinatorial nano-biocomposites (cNBC). Two strategies were used for disordered material synthesis. Firstly, incorporation of powdered/suspended nanomaterial by using the growth process of biofilm. Secondly, biofilm was used as a template for synthesis of semiconducting and metallic nanostructures. Fractal distribution of semiconductor-semiconductor and metal-semiconductor junctions were obtained as verified by Energy Dispersive X-Ray Spectroscopy (EDX) mapping, performed on scanning electron micrographs. Current-voltage curves for these materials illustrated emergent behavior from the fractal network of logic (voltage) gates [2]. Information transfer through this material was studied using AC voltage input and studying the phase and amplitude change in obtained output signal. The output from random circuitry was obtained in terms of zinc oxide luminescence. The obtained cNBCs were living materials, as shown by live-dead staining. This work demonstrates nano-incorporated biofilms as a tunable, living, bioelectronics platform, that may be adapted according to fabrication needs.

References:
[1] Ray, Sanhita, et al. "Emerging Electrical Properties of Graphene incorporated Photosynthetic Biofilms." bioRxiv (2017): 132225.
[2] Park, Won Il, et al. "ZnO nanorod logic circuits." Advanced Materials 17.11 (2005): 1393-1397.

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