Fig. 4.

Voltage dependence and nanodiamond trapping. a–d Applied voltage was gradually increased at a frequency of 1 MHz and a greater number of trapped beads was observed at the trapping sites. e The occupancy (%) of the trapping sites was monitored as the applied bias amplitude was increased. The V _min for 190 nm polystyrene beads was 500 mV. f Nanodiamond particles were trapped at the trapping sites by applying 2 V and 100 kHz frequency