A computing device comprising: a heat generating electronic component ; a housing that supports the heat generating electronic component , the housing having an inner surface and an outer surface; a thermal management device supported by the housing , the thermal management device comprising: a plate having a first surface and a second surface , the second surface of the plate facing the inner surface of the housing , the first surface of the plate partially defining a chamber of the thermal management device ; walls having a first end and a second end , the walls being disposed on the plate and extending away from the first surface of the plate , at the first end , to the second end , the walls partially defining the chamber of the thermal management device ; a layer of first material disposed on the second end of the walls , the layer of first material partially defining the chamber ; and a fluid disposed in the chamber ; wherein the thermal management device further comprises capillary features disposed on the first surface of the plate ; and wherein at least some of the capillary features are channels chemically etched onto the first surface of the plate. a heat generating electronic component ; a housing that supports the heat generating electronic component , the housing having an inner surface and an outer surface; a thermal management device supported by the housing , the thermal management device comprising: a plate having a first surface and a second surface , the second surface of the plate facing the inner surface of the housing , the first surface of the plate partially defining a chamber of the thermal management device ; walls having a first end and a second end , the walls being disposed on the plate and extending away from the first surface of the plate , at the first end , to the second end , the walls partially defining the chamber of the thermal management device ; a layer of first material disposed on the second end of the walls , the layer of first material partially defining the chamber ; and a fluid disposed in the chamber ; wherein the thermal management device further comprises capillary features disposed on the first surface of the plate ; and wherein at least some of the capillary features are channels chemically etched onto the first surface of the plate. a plate having a first surface and a second surface , the second surface of the plate facing the inner surface of the housing , the first surface of the plate partially defining a chamber of the thermal management device ; walls having a first end and a second end , the walls being disposed on the plate and extending away from the first surface of the plate , at the first end , to the second end , the walls partially defining the chamber of the thermal management device ; a layer of first material disposed on the second end of the walls , the layer of first material partially defining the chamber ; and a fluid disposed in the chamber ; wherein the thermal management device further comprises capillary features disposed on the first surface of the plate ; and wherein at least some of the capillary features are channels chemically etched onto the first surface of the plate. <EOS>