3.2 Influence of Well Fill Volume on kLa
To investigate the influence of the fill volume on kLa, the kLa was measured at three well volumes (150, 200, 300 µL). As seen in Figure 2C, at a fill volume of 150µL, kLa values ranged from 12.37 h-1(Unmixed), 14.64 h -1 (3500 rpm) 34.2 h-1 (6500 rpm) to 88.2 h -1 (9000 rpm). At a fill volume of 200 µL, kLa values ranged from 9.60 h-1 (Unmixed), 8.88 h -1 (3500 rpm), 33.6 h -1 (6500 rpm) to 89.28 h-1 (9000 rpm). At a fill volume of 300 µL, kLa values ranged from 3.72 h -1(Unmixed), 9.12 h-1 (3500 rpm), 19.44 h-1 (6500 rpm) to 37.2 h -1 (9000 rpm). As fill volume increased, there was a decrease in observed kLa at a given rotational speed, a trend consistent with comparable sized microreactors [5,20,21]. The observed trend is expected, due to kLa being volume specific. Further, as discussed there is a critical rotational speed, beyond which there is an exponential increase in kLa. As demonstrated in Figure 2C, this critical value is dependent on fill volume, whereby the higher the well fill volume, the higher rotational speed required to reach the exponential increase in kLa.