M.Sc Thesis | |
M.Sc Student | Eshel Yoni |
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Subject | Long Range Charge Transport Across Biological Materials: Measurements, Simulations and Applications |
Department | Department of Nanoscience and Nanotechnology | Supervisor | ASSOCIATE PROFESSOR Nadav Amdursky |
Full Thesis text | ![]() |
From cellular respiration to neuron firing, electronic and ionic charge transfer are key aspects of many biological functions. Our understanding of such processes in biology and their importance is still limited, and electrical properties of biological material and biology interaction with electrical signals is studied widely. In this thesis, we combine two different projects with a common denominator of bio-related charge transfer. Our two projects will touch two aspects of the field through simulations, bacterial nanowire and conductive scaffolds for tissue engineering.
When focusing on
electrons as charge carriers, up until lately, long-distance biological electron
transport was considered to be at about . However, recent discoveries of
bacterial nanowires revealed electron transfer along distances in the
millimetric scale and with high conductivity, challenging the previously perceived
long-range biological charge transfer. Accordingly, in our bacterial nanowire
chapter we tackle these recent findings directly, while hypothesizing that the
common incoherent electron transport might not be the predominant electron
transfer mechanism across the bacterial nanowire. Our goal here is to offer a
new electron transport mechanism that might explain very long-range electron
diffusion across this biological material. In our simulations, we find that a
mixed conductance model involving both incoherent and coherent steps can be
more appropriate for the bacterial nanowire system. Better understanding of
these mechanism could prove useful in improving and enhancing existing
applications such as in microbial fuel cells, and biosensing.
This interface of biology and conductive materials lately entered the field of cardiac and neuronal tissue engineering, where conductive scaffold showed increased tissue growth and connectivity and support cells synchronizing, but with little understanding as to the mechanism behind this affect. Hence, even though this interesting application of conductive scaffold seems promising, without understanding this phenomenon, it will be hard to advance its use. As such, in our conductive scaffold section, we aim in deciphering the electrical interface between the conductive scaffold to the engineered tissue. We model the electrical response of cardiac and neurons cells as well as their interaction with the conductive scaffold and show specifically what is the electrical role of the scaffold in propagating the signal and bridge across large distances and scar tissue.