  Molecular Communication (MC) is a bio-inspired communication paradigm
utilizing molecules for information transfer. Research on this unconventional
communication technique has recently started to transition from theoretical
investigations to practical testbed implementations, primarily harnessing
microfluidics and sensor technologies. Developing accurate models for
input-output relationships on these platforms, which mirror real-world
scenarios, is crucial for assessing modulation and detection techniques,
devising optimized MC methods, and understanding the impact of physical
parameters on performance. In this study, we consider a practical microfluidic
MC system equipped with a graphene field effect transistor biosensor
(bioFET)-based MC receiver as the model system, and develop an analytical
end-to-end frequency-domain model. The model provides practical insights into
the dispersion and distortion of received signals, thus potentially informing
the design of new frequency-domain MC techniques, such as modulation and
detection methods. The accuracy of the developed model is verified through
particle-based spatial stochastic simulations of pulse transmission in
microfluidic channels and ligand-receptor binding reactions on the receiver
surface.
