  A well-defined insulating layer is of primary importance in the fabrication
of passive (e.g. capacitors) and active (e.g. transistors) components in
integrated circuits. One of the most widely known 2-Dimensional (2D) dielectric
materials is hexagonal boron nitride (hBN). Solution-based techniques are
cost-effective and allow simple methods to be used for device fabrication. In
particular, inkjet printing is a low-cost, non-contact approach, which also
allows for device design flexibility, produces no material wastage and offers
compatibility with almost any surface of interest, including flexible
substrates. In this work we use water-based and biocompatible graphene and hBN
inks to fabricate all-2D material and inkjet-printed capacitors. We demonstrate
an areal capacitance of 2.0 \pm 0.3 nF cm^(-2) for a dielectric thickness of
\sim 3 \mu m and negligible leakage currents, averaged across more than 100
devices. This gives rise to a derived dielectric constant of 6.1 \pm 1.7. The
inkjet printed hBN dielectric has a breakdown field of 1.9 \pm 0.3 MV cm^(-1).
Fully printed capacitors with sub-/mu m hBN layer thicknesses have also been
demonstrated. The capacitors are then exploited in two fully printed
demonstrators: a resistor-capacitor (RC) low-pass filter and a graphene-based
field effect transistor.
