Schematics of the μBC: (a) patterned PDMS layer, (b) microstructured glass bottoms with gold mirror for optical detection or with microheater, (c) PDMS-glass-microchip, (d) zoom in of implemented fluidic interface, (e) zoom in of the out-of-plane lens design that is patterned in PDMS to optically monitor bubble formation, (f) zoom in of implemented optical elements for OD monitoring in x-axis (in-plane).