  Reliable and consistent preparation of atom probe tomography (APT) specimens
from aqueous and hydrated biological specimens remains a significant challenge.
One particularly difficult process step is the use of a focused ion beam (FIB)
instrument for preparing the required needle-shaped specimen, typically
involving a "lift-out" procedure of a small sample of material. Here, two
alternative substrate designs are introduced that enable using FIB only for
sharpening, along with example APT datasets. The first design is a laser-cut
FIB-style half-grid close to those used for transmission-electron microscopy,
that can be used in a grid holder compatible with APT pucks. The second design
is a larger, standalone self-supporting substrate called a "crown", with
several specimen positions that self-aligns in APT pucks, prepared by
electrical discharge machining (EDM). Both designs are made nanoporous, to
provide strength to the liquid-substrate interface, using chemical and vacuum
dealloying. We select alpha brass a simple, widely available, lower-cost
alternative to previously proposed substrates. We present the resulting
designs, APT data, and provide suggestions to help drive wider community
adoption.
