  This paper reports on the development and testing of a novel, highly
efficient technique for the injection of very rare species into electron beam
ion traps (EBITs) for the production of highly charged ions (HCI). It relies on
in-trap laser-induced desorption of atoms from a sample brought very close to
the electron beam resulting in a very high capture efficiency in the EBIT. We
have demonstrated a steady production of HCI of the stable isotope
$^{165}\mathrm{Ho}$ from samples of only $10^{12}$ atoms ($\sim$ 300 pg) in
charge states up to 45+. HCI of these species can be subsequently extracted for
use in other experiments or stored in the trapping volume of the EBIT for
spectroscopic measurements. The high efficiency of this technique expands the
range of rare isotope HCIs available for high-precision nuclear mass and
spectroscopic measurements. A first application of this technique is the
production of HCI of the synthetic radioisotope $^{163}\mathrm{Ho}$ for a
high-precision measurement of the $Q_{\mathrm{EC}}$-value of the electron
capture in $^{163}\mathrm{Ho}$ within the Electron Capture in Holmium
experiment (ECHo collaboration) ultimately leading to a measurement of the
electron neutrino mass with an uncertainty on the sub-eV level.
