To begin, clean a silicon substrate using isopropyl alcohol, and let it air dry. Using a pipette, place one microliter of polystyrene beads suspended in water onto the center of the substrate. Place the polystyrene beads added substrate in a storage compartment containing bentonite clay dessicant to allow the water to evaporate.
Examine the dried polystyrene beads substrate and a previously prepared polyvinyl alcohol or PVA coated substrate under an optical microscope. Using ultra fine tweezers, gently losing the beads, then collect a few beads using a fine hair paintbrush and gently tap the hairs of the paintbrush over the freshly PVA coated wafer. Repeat collecting the beads until individual polystyrene beads adhere to the PVA surface as confirmed by optical microscopy.
Deposition of the polystyrene beads was confirmed by scanning electron microscopy imaging of the five micrometer bead on top of a pristine silicon substrate on top of a PVA film and covered with PVA.
