  Useful materials must satisfy multiple objectives, where the optimization of
one objective is often at the expense of another. The Pareto front reports the
optimal trade-offs between competing objectives. Here we report a self-driving
laboratory, "Ada", that defines the Pareto front of conductivities and
processing temperatures for palladium films formed by combustion synthesis. Ada
identified previously untested combustion synthesis conditions that resulted in
the discovery of lower processing temperatures (below 200 {\deg}C) relative to
the prior art for this technique (250 {\deg}C), a temperature difference that
makes the coating of different commodity plastic materials possible (e.g.,
Nafion, polyethersulfone). These conditions enabled us to use combustion
synthesis to spray coat uniform palladium films with moderate conductivity (1.1
$\times$ 10$^5$ S m$^{-1}$) at 191 {\deg}C. Spray coating at 226 {\deg}C
yielded films with conductivities (2.0 $\times$ 10$^6$ S m$^{-1}$) comparable
to those of sputtered films (2.0 to 5.8 $\times$ 10$^6$ S m$^{-1}$). This work
shows how self-driving laboratories can discover materials satisfying multiple
objectives.
