“…For instance, applying nanodiamond coating technology to fluid channels can increase the speed of sperm swimming in the channel, which can be used for sperm separation. 11 However, the interaction of nanodiamond with the differential maturity stages (uncapacitated and capacitated) of sperm and their subsequent effects on sperm characteristics is not well understood, making clinical application challenging. 12 In microfluidic technology, micro-structures formed in channels can separate sperm depending on their motility, [13][14][15][16][17][18] and the rheotaxis, which guides sperm's stream against the flow, can be utilized in microchannels to obtain highly motile sperm.…”