A thermal management device for dissipating heat from an electrical component includes a volume of working fluid configured to change from a liquid state to a vapor state in response to being heated by the electrical component. The thermal management device also includes a working fluid chamber configured to move the working fluid. The working fluid chamber includes an impermeable outer portion and a porous inner portion integrally formed with and connected to the impermeable outer portion. The inner portion is configured to move the working fluid when in the liquid state toward the electrical component. The impermeable outer portion is made of a first material and the porous inner portion is made of a second material. The first material is different from the second material.