  Simple and easy to implement testbeds are needed to further advance molecular
communication research. To this end, this paper presents an in-vessel molecular
communication testbed using magnetic nanoparticles dispersed in an aqueous
suspension as they are also used for drug targeting in biotechnology. The
transmitter is realized by an electronic pump for injection via a Y-connector.
A second pump provides a background flow for signal propagation. For signal
reception, we employ a susceptometer, an electronic device including a coil,
where the magnetic particles move through and generate an electrical signal. We
present experimental results for the transmission of a binary sequence and the
system response following a single injection. For this flow-driven particle
transport, we propose a simple parameterized mathematical model for evaluating
the system response.
