A microfluidic system includes a microfluidic device connected to a bubble trap device whereby fluid flowing to the microfluidic device passes through the bubble trap device to remove gas bubbles prior to entering the microfluidic device. The bubble trap can include a separation chamber and an exhaust chamber separated by a hydrophobic porous membrane and gas bubbles in the fluid entering the separation chamber pass through the hydrophobic porous membrane into the exhaust chamber while the fluid remains in the separation chamber. The bubble trap can be formed by bonding a first body portion to a first side of the hydrophobic porous membrane and bonding a second body portion to a second side of the hydrophobic porous membrane. The exhaust chamber can be connected to an elongated exhaust channel that limits the evaporation losses of the fluid through the hydrophobic porous membrane.