A quasi-isotropic silicon etching was performed to define pillars underneath the silicon oxide chips (Figure ). Next the photoresist was removed (Figure ), and the whole wafer was oxidized (Figure ) to convert the silicon pillars in silicon oxide pillars. At this technological stage, the microchips remain physically anchored to the substrate for their posterior chemical functionalization. Figure exhibits the SEM image of fabricated silicon oxide microchips anchored to the silicon substrate. When required, the chips can be removed from the wafer by mechanical peel-off using a water-soluble mounting media layer and subsequently recollected in Eppendorf tubes.