  The promise of increasing channel counts in high density ($> 10^4$) neural
Microelectrode Arrays (MEAs) for high resolution recording comes with the curse
of developing faster characterization strategies for concurrent acquisition of
multichannel electrode integrities over a wide frequency spectrum. To
circumvent the latency associated with the current multiplexed technique for
impedance acquisition, it is common practice to resort to the single frequency
impedance measurement (i.e. $Z_{1 \text{kHz}}$). This, however, does not offer
sufficient spectral impedance information crucial for determining the capacity
of electrodes at withstanding slow and fast-changing stimulus and recordings.
In this work, we present \textit{HermEIS}, a novel approach that leverages
single cycle in-phase and quadrature signal integrations for reducing the
massive data throughput characteristic of such high density acquisition
systems. As an initial proof-of-concept, we demonstrate over $6$ decades of
impedance bandwidth ($5\times10^{-2} - 5\times10^{4}\text{ Hz}$) in a parallel
$4$-channel potentiostatic setup composed of a custom PCB with off-the-shelf
electronics working in tandem with an FPGA.
