Bubble formations. “Life happens in the gaps” one of my ongoing themes.
“- Dead ends, microwells, and sharp corners. Wetting in these structures is difficult and air can be trapped (Fig. 1a and 1b). These structures can be functionalized to increase their wettability.
- Wide low chambers. The use of these chambers is very common in microfluidics to perform reactions or to grow cells (Fig. 1c). However, the liquid front tends to have different speeds on both sides of the chamber and thus, a bubble can potentially form. The use of phase-guides might avoid the liquid front from advancing too fast in one direction than in the other. Pillars are another structure that equalizes the speed of the liquid front.
- Contact regions between two parts of a device. The surface where binding between two parts happens usually present irregularities, being a great place for bubble nucleation (Fig. 1d). Therefore, it is recommendable to use a cladding material to bind these structures.