Biasing Distance and Heterogeneous Solution Effects in Liquid Gated Graphene Field Effect Transistors
Open Access
Author:
Felins, Michael
Graduate Program:
Engineering Science and Mechanics
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
October 25, 2022
Committee Members:
Albert Segall, Program Head/Chair Saptarshi Das, Thesis Advisor/Co-Advisor Mark William Horn, Committee Member Sahin K Ozdemir, Committee Member
Keywords:
Liquid gating Graphene Biosensor FET
Abstract:
Liquid gating is an important, novel detection mechanism for transistor devices
with a variety of applications in chemical and biological sensing. While applications
acknowledge the existence of liquid gating, they rarely consider the formed electric
double layer (EDL) and the effects bias distance and liquid composition may
have. Local biasing and local liquid composition can be considered in several
biosensing applications, and can be directly applied to neural sensing, as neural
activity is the largely the sum of action potentials, neurotransmitters, and ion
concentration changes. This work studies liquid biasing distances and heterogeneous
liquid effects in liquid gated graphene field-effect transistor (GFET) devices. The
former is done by evaluating key graphene device characteristics (such as the
Dirac point, transconductance, etc.) in relation to biasing distance; the latter is
done by spatially mapping characteristics of devices gated by the heterogeneous
liquid. These resulting trends suggest that the EDL itself should be a factor when
considering any biological sensing device and should be an additional consideration
alongside current neural sensing techniques.
