Novel cooling systems with very low material budget are being fabricated and studied. They consist of silicon wafers in which microchannels are etched and closed by bonding another wafer. This cooling option is being considered for future HEP detectors of the sLHC and linear colliders. It is currently under investigation as an option for the cooling of the NA62 Gigatracker silicon pixel detector and its front-end electronics where the microfabricated cooling plate would stand directly in the beam. In this particular case, microchannel cooling meets both the very aggressive X0 (0.15%) specifications and the anticipated 2 W/cm2 power dissipation by the active electronics.