The present application discloses two-phase cooling devices that may include at least three substrates: a metal with a wicking structure, an intermediate substrate and a backplane. The titanium thermal module may be adapted for use in a mobile device, such as a portable device or smartphone, where it may offer compelling performance advantages. The thermal module may also have a metal layer which may act as a shield for radiation or an antenna for radiation, or may add mechanical strength to the thermal module.